Neuro-Ophthalmology & Neuro-Otology

Updated 06.22.2023
Released 12.18.2014
Expires For CME 06.22.2026

Sensorineural hearing loss

Author: Douglas J Lanska MD FAAN MS MSPH

Introduction

Overview

In this article, the author explains the clinical presentation, pathophysiology, prevention, diagnostic workup, and management of sensorineural hearing loss. Sensorineural hearing loss is most often caused by abnormalities in the hair cells of the organ of Corti in the cochlea. The hair cells may be abnormal at birth or damaged during an individual’s lifetime. There are both external causes of damage (eg, noise, trauma, and infection) and intrinsic abnormalities (eg, some genetic disorders). Less commonly, there may be dysfunction of the auditory nerve as a result of mass lesions, trauma, demyelination, infectious or inflammatory disorders, autoimmune processes, and nutritional disorders.

Key points

	• With sensorineural hearing loss, hearing is impaired for both air- and bone-conducted sounds.
	• There are different audiogram patterns for different causes of sensorineural hearing loss: presbycusis is typically associated with a downward-sloping, high-frequency loss pattern; noise-induced hearing loss is associated typically with a notched pattern (generally at 4 kHz); and Meniere disease is associated with a low-frequency trough pattern.
	• More than 50% of prelingual deafness is genetic, most often autosomal recessive and nonsyndromic. Genetic bases have also been identified for some postlingual deafness.
	• Functionally significant hearing loss is very common in the elderly, affecting about a third of those age 70 years or older, adversely impacting quality of life and ability to carry out routine activities and interact socially and, thereby, contributing to isolation, frustration, disappointment, and depression
	• Situations where prevention is most likely to impact hearing outcomes are the prevention of noise-induced hearing loss and the prevention of drug ototoxicity.
	• Cochlear implantation may improve audiologic performance and quality of life in elderly patients, even into their eighties

Historical note and terminology

In the second century, Galen of Pergamon (c130-c200) believed that hearing loss or deafness could be caused by dysfunction of the ear, acoustic nerve, or brainstem (108). Nevertheless, relatively little was known about the anatomy and physiology of the ear until the discovery of two of the middle ear ossicles (malleus and incus) in the early 16th century by Jacopo Beregario da Carpi (ca. 1460-ca. 1530) in the Provence of Modena, Italy (108).

Galen of Pergamon

Lithograph of Galen (AD 129-c200/c216) of Pergamon (modern-day Bergama, Turkey). Galen was a prominent Roman physician, surgeon, and philosopher of Greek ethnicity. Lithograph (c1865) by Grégoire & Deneux, Paris, of portrait b...
Jacopo Berengario da Carpi

Seventeeth century portrait of Jacopo Berengario da Carpi displayed in the Museum of the "Palazzo dei Pio," in Carpi, Province of Modena, Italy. (Courtesy of the History of Medicine Topographical Database: http://himetop.wikidot.c...

In 1543, in his De humani corporis fabrica (On the fabric of the human body), Andreas Vesalius (1514-1564) of Brussels later named the two then-known ossicles the “malleus” and the “incus”; he was the first to illustrate these structures (146), and he may have discovered the tensor tympani muscle. Nevertheless, despite the great advancements in anatomy that Vesalius brought about, otology and, particularly, the anatomy of the inner ear were relatively neglected by Vesalius (108; 71).

Andreas Vesalius

Woodcut frontispiece portrait of Flemish anatomist, physician, and surgeon Andreas Vesalius (1514-1564) from the Fabrica (1543). (Courtesy of the U.S. National Library of Medicine.)
Andreas Vesalius performing a public anatomy

Detail of Andreas Vesalius performing a public anatomy. (From the illustrated title page of the first edition of Vesalius’s De humani corporis fabrica (On the fabric of the human body) in 1543 (Vesalii 1543).)
Malleus and incus, the first drawing

The first published drawing of the malleus and incus, from the De humani corporis fabrica (On the fabric of the human body) by Andreas Vesalius. The same figure was shown in the 1543 and 1555 editions. This is reproduced fr...

Gabrielle Falloppio of Modena (Fallopius; 1523-1562) described all three auditory ossicles, the oval and round windows, the chorda tympani (although he was unclear whether this was a nerve), and the eponymous fallopian aqueduct or canal through which the facial nerve passes in the temporal bone (108).

Gabriel Falloppius

Italian professor of anatomy and surgery Gabriel Falloppius Mutinensis (Gabriele Falloppio of Modena, or Fallopius; 1523-1562). The years given in the figure (1551-1563) are the years of his appointment in Padua, although he died ...

Fallopius recognized the two parts of the inner ear: the “cochlea” and the “labyrinth,” the latter being composed of the vestibule and the semicircular canals (108).

Bartolomeo Eustachi (1524-1574) apparently independently described the stapes, presented cross sections of the temporal bone, and also provided a more complete description of the eponymous Eustachian tube that links the nasopharynx to the middle ear than was known from vague descriptions by Aristotle, Celsus, Vesalius, and others (108).

Bartolomeo Eustachi

Italian anatomist Bartolomeo Eustachi (1524-1574). (Courtesy of the U.S. National Library of Medicine.)
Bartolomeo Eustachi performing a human dissection

Bartolomeo Eustachi performing a human dissection, with several dog carcasses on the ground for comparative anatomical demonstrations. Illustration from the title page of Eustachi’s Tabulae Anatomicae (Eustachii 1783).
Cross section of the temporal bone by Bartolomeo Eustachi

Cross section of the temporal bone through the external auditory meatus, the tympanic cavity surrounding the bones of the middle ear, the superior and horizontal semicircular canals, and the cochlea. Illustration from Tabula 45...

Little progress was made in understanding the anatomy and physiology of hearing during the 17th century, particularly because after English physician William Harvey (1578-1657) published De Motu Cordis (On the Motion of the Heart and Blood) in 1628, anatomists and physiologists focused heavily on the cardiovascular system and ignored the sensory organs. English physician Thomas Willis (1621-1675) almost a half century after Harvey summarized the contemporary understanding of hearing (153).

Thomas Willis

English physician Thomas Willis (1621-1675) provided a clear summary of the limited understanding of the anatomy and physiology of the ear in the 17th century. (Courtesy of the U.S. National Library of Medicine.)

He claimed that the auricle collected and channeled sound particles toward the tympanic membrane, which facilitated or prepared the sound for reception in the inner ear. The internal auditory muscles and the ossicles served to sort the sounds. Sounds are then transmitted through the oval window to reverberate in the semicircular canals before reaching the cochlea and then the acoustic nerve. Willis was the first to realize that the cochlea is the auditory sense organ, ie, the site of sensory transduction (108).

The most important otological research in the 18th century was that of Italian physician-scientist Antonio Scarpa (1747-1832). In his Disquisitiones Anatomicae de Audiu et Olfactu (1789), Scarpa was the first to describe the membranous labyrinth (108). Among later 18th-century otological researchers was Dutch physician Fredrik Ruysch (1638-1731), whose meticulous drawings and skill in the technique of anatomical injection showed details as fine as the injected vessels in the mucous membrane of the complete ossicular chair.

Antonio Scarpa

Italian physician-scientist Antonio Scarpa (1747-1832) described the membranous labyrinth. (Courtesy of the U.S. National Library of Medicine.)
Fredrik Ruysch

Dutch physician Fredrik Ruysch (1638-1731). (Courtesy of the U.S. National Library of Medicine.)
Complete ossicular chain by Fredrik Ruysch

Meticulous drawing of the injected vessels in the mucous membrane of the complete ossicular chain by Fredrik Ruysch (1638-1731) (Ruyschius 1744).

In 1821, French physician Jean-Marc Gaspard Itard (1774-1838) published Traité des Maladies de l'Oreille et de l'Audition, a monograph that laid the foundation of modern otology with the results of Itard's studies of ear diseases in over 170 cases (72). Itard was also later recognized as an educator of deaf-mutes.

Jean-Marc Gaspard Itard

French physician Jean-Marc Gaspard Itard (1774-1838). (Courtesy of the U.S. National Library of Medicine.)

French otologist Prosper Ménière (1799-1862) devoted much of his career on diseases of the ear. Meniere studies at the Imperial Institute for Deaf Mutes in Paris (Institut Royal des Sourds et Muets à Paris) helped him recognize a group of patients with episodic and progressive auditory and vestibular symptoms, which he attributed to inner ear pathology (73).

Prosper Ménière

French otologist Prosper Ménière (1799-1862). (Courtesy of the U.S. National Library of Medicine.)

Ménière established that vertigo might be a symptom of labyrinthine disease and specifically recognized a fairly homogenous group of patients with auditory and vestibular dysfunction that he linked to inner ear pathology. Although largely discounted during his lifetime, this work received increased recognition after his death when in 1874 French neurologist Jean-Martin Charcot (1825-1893) labeled the disease “Maladie de Ménière.” Charcot also noted that episodic symptoms in affected patients ceased when the deafness became complete.

German physician, physiologist, and physicist Hermann Ludwig Ferdinand von Helmholtz (1821-1894) was a major contributor to sensory physiology (74).

Hermann Ludwig Ferdinand von Helmholtz

German physician, physiologist, and physicist Hermann Ludwig Ferdinand von Helmholtz (1821-1894). (From Popular Science Monthly 1874;5.)

While serving as professor of physiology at the University of Heidelberg, Helmholtz wrote Die Lehre von den Tonempfindungen als physiologische Grundlage für die Theorie der Musik (The Doctrine of the Sensations of Tone as a Physiological Basis for the Theory of Music, 1863), in which he introduced his place theory of frequency discrimination (54; 71). Helmholtz suggested that the ear could be understood as a sensory organ whose purpose is to decompose complex sounds (resulting from an admixture of various tones of different frequencies) into their component frequencies--a spectrum analyzer. Helmholtz proposed that each section of the tapering basilar membrane of the cochlea operated as an independent resonator with a natural period of vibration, or resonance, that responded only to sounds that vibrated at that period, like the tensioned strings on a harp. Based on the anatomy of the basilar membrane, which is three to four times wider at the apex than the base, Helmholtz postulated that high-frequency tones are perceived near the base of the cochlea, whereas lower frequencies are perceived toward the apex, just as short harp or piano strings produce high-frequency notes whereas long strings produce low-frequency notes. Helmholtz’s theory of hearing was a place theory, according to which the pitch of a sound is determined by the place where the membrane vibrates, in contrast to temporal or timing theories of hearing in which the frequency of neural firing determines the perception of pitch (71).

As early as 1885, an “auditory chart” was developed that graphically presented auditory acuity as a function of frequency, with responses based on testing with a set of standard tuning forks (148). Later means of graphically presenting auditory acuity as a function of frequency were developed in the early 20th century (148). In 1899, American psychologist Carl Emil Seashore (1866-1949) invented an audiometer, which was marketed initially around 1900 (118; 128; 91; 148).

Carl Seashore

Carl Seashore developed one of the first commercial audiometers around 1899. (Contributed by Dr. Douglas Lanska.)

In the 1920s, Western Electric developed a commercially successful electronic audiometer (148); this went through a series of technological improvements, including the incorporation of bone-conduction testing capability by 1928.

In the 1940s and 1950s, Hungarian-born biophysicist and physiologist Georg (György) von Bekesy (1899-1972) studied experimentally how sound is analyzed and communicated in the cochlea and extended research that had begun in the 19th century in psychoacoustics by Helmholtz (11; 12; 71). Bekesy invented an early type of automated audiometer, which was released in 1946 and continued in use until the 1990s. Bekesy went on to develop a modern place theory of hearing to explain how the cochlea functions as a frequency analyzer, work that overthrew Helmholtz’s earlier resonance theory. Bekesy’s theory was based on his discovery that sound vibrations travel along the basilar membrane in waves, peaking at different places, where nerve receptors determine pitch and loudness. Bekesy found that the entire basilar membrane vibrates, although the point of maxim amplitude varies in a systematic way with the fundamental frequency of the vibration because of the tapering shape of the membrane as it stretches along the length of the cochlea. This is the underlying basis for tonotopic or place coding, in which the inner ear hair cells with the greatest response code for the fundamental frequency of the sound. As Helmholtz had postulated for different reasons, Bekesy found that high-frequency tones are perceived near the base of the cochlea whereas lower frequencies are perceived toward the apex. For his “discoveries of the physical mechanism of stimulation within the cochlea,” Bekesy was awarded the 1961 Nobel Prize in Physiology or Medicine (12; 73).

Other studies, however, have indicated that pitch is coded by a combination of rate information for lower frequencies and place information for higher frequencies; in consequence, a number of rate-place schemes have been proposed (22). Moreover, since the 1970s we have learned that the ear does not act passively, as both Helmholtz and Bekesy had thought, but instead is an active detector (77; 38; 149; 60; 46; 65).

Clinical manifestations

Presentation and course

	• Prelingual hearing loss is present before speech develops, whereas postlingual hearing loss occurs after normal speech development.
	• Children with postlingual deafness experience a much higher linguistic achievement level than those with prelingual deafness.
	• Even children with mild to moderate sensorineural hearing loss have auditory processing deficits that adversely affect language development in children.
	• Patients affected by sensorineural hearing loss have difficulty hearing the speech of others, which sounds mumbled or muffled, and typically have difficulty understanding conversations when there is background noise.
	• Those with high-frequency sensorineural hearing loss, as from presbycusis or noise-induced hearing loss, have particular difficulty perceiving or discriminating high-pitched consonants (eg, ch, f, k, s, t, or th) compared to lower-pitched vowel sounds and also have more difficulty hearing the higher-pitched voices of women and children than they have hearing men’s voices.
	• An individual has sensorineural hearing impairment if the average bone-conducted threshold at 500 Hz, 1000 Hz, and 2000 Hz (ie, the “speech-frequency pure-tone average”) is greater than 25 dB.
	• Sensorineural hearing loss can be considered asymmetric if the interaural difference in pure-tone thresholds is at least 10 dB at two frequencies or at least 15 dB at one frequency.

Prelingual hearing loss by definition is present before speech develops, whereas postlingual hearing loss occurs after the development of normal speech. All congenital hearing loss is necessarily prelingual, but not all prelingual hearing loss is congenital. Children with postlingual deafness experience a much higher level of linguistic achievement than those with prelingual deafness. Children who are prelingually deaf and cannot hear sounds below 60 decibels (ie, about the loudness of a vacuum cleaner) will not be able to develop oral language skills comparable to those of their normal-hearing peers. Children born with profound hearing impairment (ie, of 90 decibels or more, or about the loudness of a food blender) generally have delayed or impaired speech, language, and reading development. Even children with mild-moderate unilateral sensorineural hearing loss have a higher frequency of speech and language delay, so such children also need close monitoring of speech, language, and auditory development and functioning (83).

Children with mild to moderate sensorineural hearing loss have auditory processing deficits that adversely affect language development in children (50). Deficits in a general auditory processing are necessary but not sufficient for language difficulties, whereas deficits in slow-rate amplitude modulation (envelope) detection are sufficient but not necessary for language difficulties, and deficits in the discrimination of a single speech contrast (eg, /bɑ/ vs. /dɑ/) are neither necessary nor sufficient for language difficulties (50).

Vestibular dysfunction is a common comorbidity associated with childhood sensorineural hearing loss (53; 41). Early identification of vestibular dysfunction in children with sensorineural hearing loss facilitates early intervention to mitigate the negative impact on motor, behavioral, and neurocognitive development (53; 89).

Patients affected by sensorineural hearing loss have difficulty hearing the speech of others, which sounds mumbled or muffled, and typically have difficulty understanding conversations when there is background noise. Those with high-frequency sensorineural hearing loss, as from presbycusis or noise-induced hearing loss, have particular difficulty perceiving or discriminating high-pitched consonants (eg, ch, f, k, s, t, or th) compared to lower-pitched vowel sounds and also have more difficulty hearing the higher-pitched voices of women and children than they have hearing men’s voices. Some sounds may be distorted or perceived as overly loud: when talking at a regular pitch and volume, the patient may have difficulty discriminating speech sounds, whereas compensatory efforts by the speaker to talk in a lower register and more loudly can produce an irritated response from the patient (eg, “You don’t have to yell!”) (75). Talking very loudly or shouting does not necessarily help understanding because it primarily increases the intensity level of vowels rather than consonants; in addition, loud sounds are often uncomfortable for such patients because of recruitment. In patients with sensorineural hearing loss, sounds are also frequently distorted so that a pure tone may be heard as a buzz, broadband noise, or a complex mixture of tones. Some patients experience diplacusis (ie, the perception of a single auditory stimulus as two separate sounds, which may differ in pitch or in time). In addition, sensorineural hearing loss contributes significantly to isolation, stress, and depression and may also cause or contribute to paranoia (28; 163; 64; 126). Furthermore, sensorineural hearing loss is often associated with subjective tinnitus, which for some patients may be the most troubling symptom as it may impair concentration, preclude adequate sleep, and cause or contribute to anxiety and depression.

An individual has sensorineural hearing impairment if the average bone-conducted threshold at 500 Hz, 1000 Hz, and 2000 Hz (ie, the “speech-frequency pure-tone average”) is greater than 25 dB (09). Sensorineural hearing impairment is graded by the magnitude of the speech-frequency pure-tone average in the better ear, and for clinical purposes, pure-tone averages of 25 dB, 40 dB, and 60 dB can be considered the thresholds of mild, moderate, and severe hearing impairments (26; 47; 09). The World Health Organization grades of hearing impairment are similar but are assessed in the better ear based on a 4-frequency pure tone average of the hearing thresholds at 500, 1000, 2000, and 4000 Hz (Table 1) (155). The degree of hearing loss may also be specified for each frequency or for each frequency region (ie, low, mid, or high frequencies on the audiogram) based on the following broad frequency ranges: low (lower than 500 Hz), middle (501 to 2000 Hz), or high (higher than 2000 Hz) (Table 2) (19).

Table 1. World Health Organization Grades of Hearing Impairment (assessed in better ear)

Hearing threshold level*	Grade	Impairment	Description
25 or less	0	No impairment	No or very slight hearing problems. Able to hear whispers.
26-40	1	Slight	Able to hear and repeat words spoken in a normal voice at 1 meter.
41-60	2	Moderate	Able to hear and repeat words using a raised voice at 1 meter.
61-80	3	Severe	Able to hear some words when shouted into the better ear.
> 80	4	Profound	Unable to hear even a shouted voice.
*Note: Hearing threshold level, based on a 4-frequency pure tone average dB hearing level (decibels Hearing Level) at 500, 1000, 2000, 4000 Hz in the better ear.

Table 2. Degree of Hearing Loss

Degree of hearing loss	Hearing loss range (dB hearing level)
Normal Slight Mild Moderate Moderately severe Severe Profound	–10 to 15 16 to 25 26 to 40 41 to 55 56 to 70 71 to 90 91+

Sensorineural hearing loss can be categorized by laterality (ie, unilateral or bilateral, with bilateral sensorineural hearing loss further categorized by symmetry in terms of both degree and configuration), onset (sudden or insidious), and course (static or stable, fluctuating, or progressive).

Although a variety of definitions have been proposed in the literature, sensorineural hearing loss can be considered asymmetric if the interaural difference in pure-tone thresholds is at least 10 dB at two frequencies or at least 15 dB at one frequency (138). Asymmetric sensorineural hearing loss is fairly common, especially in those with a history of significant noise exposure (25; 106; 107; 138). However, asymmetric sensorineural hearing loss can rarely indicate retrocochlear pathology, such as acoustic neuroma (138).

Prognosis and complications

In children, prelingual hearing loss can lead to delayed social development, delayed language acquisition, and social isolation from hearing peers. Such problems can be ameliorated by learning and using sign language, attending a school for the deaf, and self-identifying with deaf culture, although this can increase isolation from his or her parents, particularly if they do not know, or make an effort to learn, sign language.

Those with postlingual hearing loss are also more likely to suffer from isolation, and they also experience increased levels of stress and depression compared with their normal-hearing peers; this is particularly true in the elderly, for whom significant hearing loss may also cause or contribute to paranoia (28; 163; 64; 126). Sensorineural hearing loss may also contribute to the development of dementia in the elderly; in animal models, sensorineural hearing loss may lead to dementia-related pathological changes in hippocampal neurons (121).

Biological basis

	• For sensorineural hearing loss, there is dysfunction of the cochlea (“sensory”) or the auditory nerve (“neural”); although the central auditory pathways could also be considered “neural,” hearing loss resulting from disorders of these pathways is traditionally considered separately as “central” hearing loss.
	• A clinically important distinction in cases of sensorineural hearing loss is whether the condition is “sensory” (ie, cochlear) or whether it is “neural” (ie, “retrocochlear”).
	• Cochlear disorders are typically the purview of audiologists and otolaryngologists whereas retrocochlear disorders are much more likely to reflect neurologic disorders, some of which may require neurosurgical intervention.
	• Sensorineural hearing loss is most often caused by abnormalities in the hair cells of the organ of Corti in the cochlea.

Etiology and pathogenesis

Sensorineural disorders involve dysfunction of the sensory receptors or conduction of signals from the sensory receptors to the brain. For sensorineural hearing loss, there is dysfunction of the cochlea (“sensory”) or the auditory nerve (“neural”). Although the central auditory pathways could also be considered “neural,” hearing loss resulting from disorders of these pathways is traditionally considered separately as “central” hearing loss. A clinically important distinction in cases of sensorineural hearing loss is whether the condition is “sensory” (ie, cochlear) or whether it is “neural” (ie, “retrocochlear”). Cochlear disorders are typically the purview of audiologists and otolaryngologists whereas retrocochlear disorders are much more likely to reflect neurologic disorders, some of which may require neurosurgical intervention.

Sensorineural hearing loss is most often caused by abnormalities in the hair cells of the organ of Corti in the cochlea. The hair cells may be abnormal at birth or may be damaged during an individual’s lifetime. There are both external causes of damage (eg, noise, trauma, and infection) and intrinsic abnormalities (eg, some genetic disorders). Less commonly, there may be dysfunction of the auditory nerve as a result of mass lesions, trauma, demyelination, infectious or inflammatory disorders, autoimmune processes, and nutritional disorders.

Epidemiology

	• Hearing loss is the most common birth defect and the most prevalent sensorineural disorder in developed countries.
	• About 70% of genetic hearing loss is nonsyndromic, and about 30% is syndromic.
	• More than 50% of prelingual deafness is genetic, most often autosomal recessive and nonsyndromic.
	• Half of severe childhood deafness results from simple mendelian inheritance, the vast majority (87%) of which results from autosomal recessive mutations.
	• For individuals 12 years and older in the United States, about 13% (approximately one in eight) have bilateral hearing loss, and about 20% (approximately one in five) have a unilateral or bilateral hearing loss.
	• The prevalence of hearing loss increases with age.

Hearing loss is the most common birth defect and the most prevalent sensorineural disorder in developed countries (56; 57). Two per 1000 newborns have bilateral permanent sensorineural hearing loss of at least moderate severity (40 dB or greater), but by adolescence the prevalence increases to 3.5 per 1000 (96).

Etiology of pediatric sensorineural hearing loss. Genetic hearing loss may appear as an isolated finding or as part of a syndrome (63). About 70% of genetic hearing loss is nonsyndromic, and about 30% is syndromic. More than 50% of prelingual deafness is genetic, most often autosomal recessive and nonsyndromic. Most genes associated with genetic forms of deafness are involved in hair bundle morphogenesis, form constituents of the extracellular matrix, function to maintain ion homeostasis in the cochlea, or serve as transcription factors.

Half of severe childhood deafness results from simple mendelian inheritance, the vast majority (87%) of which results from autosomal recessive mutations (40). Consanguineous progeny have a 76% higher risk of developing sensorineural hearing loss than nonconsanguineous progeny (117). Recessive inheritance is responsible for two thirds of congenital deafness (94). At least 16% of the normal population are carriers of a gene for congenital deafness (94; 95). More than 80 genetic loci have been identified among those with autosomal recessive deafness, with responsible loci present on every autosome (ie, chromosome that is not an allosome or sex chromosome). At least half of autosomal recessive nonsyndromic hearing loss is attributed to autosomal recessive deafness 1A (DFNB1A; OMIM 22090), autosomal recessive deafness 1B (DFNB1B; OMIM 612645), or digenic GJB2/GJB6 deafness (OMIM 22090). DFNB1A is caused by mutations in the GJB2 gene (the “gap junction protein, beta-2” gene) on chromosome 13q12.11, which encodes the gap-junction protein connexin 26, whereas DFNB1B is caused by mutations in the GJB6 gene (the “gap junction protein, beta-6” gene) on chromosome 13q12.11, which encodes the gap-junction protein connexin 30 (104; 04). Genes less frequently implicated in autosomal recessive nonsyndromic hearing loss are SLC26A4, MYO15A, OTOF, (DFNB9, encoding otoferlin), CDH23, TMC1, CLDN14 (DFNB29), TRIOBP, and mtDNA 12S rRNA (151; 68; 82; 109; 62). None of the genes associated with autosomal dominant nonsyndromic hearing loss accounts for a preponderance of cases.

For individuals 12 years and older in the United States, 30 million or about 13% (approximately one in eight) have bilateral hearing loss, and 48 million or about 20% (approximately one in five) have a unilateral or bilateral hearing loss (81). The prevalence of hearing loss increases with age; this change reflects the individual impacts of genetic and environmental factors as well as the interactions between specific environmental triggers and an individual's genetic predisposition, as illustrated by aminoglycoside-induced ototoxicity (75). The prevalence of hearing loss is higher in men than women across nearly all age decades and for nearly all regions of the world (02; 81; 156).

Sensorineural hearing loss in the elderly. Functionally significant hearing loss is very common in the elderly, affecting about a third of those age 70 years or older (21). This can adversely affect quality of life and compromise an older individual’s ability to carry out routine activities and interact socially, thereby contributing to isolation, frustration, disappointment, and depression (98; 99). The ability to understand spoken speech is often interpreted as an indicator of cognitive abilities, especially in the elderly, so impaired hearing often negatively influences how other people perceive and interact with an elderly person; it also contributes not infrequently to inappropriate diagnoses of dementia by clinicians. In addition, hearing impairment is a significant predictor of postural imbalance and falls in children and older individuals (147; 89).

The underlying causes of sensorineural hearing loss in the elderly are varied and include cumulative effects of prior toxic exposures, noise-induced hearing loss, age-related changes, and genetic susceptibility. Various genes are involved in late-onset hearing loss and a significant portion of cases of late-onset hearing loss is due to genetic causes (137).

Specific risk factors. A population-based cohort study in Taiwan found that patients with sensorineural hearing loss have a higher incidence of developing glaucoma, but the replicability, potential mechanisms, and significance of this finding are, as yet, unclear (24).

A systematic review and meta-analysis also identified iron-deficiency anemia as a possible risk factor for sensorineural hearing loss (93). The odds of sensorineural hearing loss were 55% higher in individuals with iron-deficiency anemia than those without. The age-specific odds ratios were 1.36 in adults and 3.67 in children.

In the National Health and Nutrition Examination Study (NHANES) database, using a national sample of the U.S. population, the presence of chronic obstructive pulmonary disease (COPD) was associated with elevated hearing thresholds (worse hearing) at each frequency (120). The presence of chronic obstructive pulmonary disease was independently associated with a 3.3 dB increase in the high-frequency pure tone average (3, 4, 6, 8 kHz), and 2.3 dB increase in the low-frequency pure tone average (.5, 1, 2 kHz) after controlling for medical, social, and environmental covariates (120). The presence of chronic obstructive pulmonary disease was independently associated with a 1.85-fold increased odds of isolated low-frequency sensorineural hearing loss.

Prevention

	• Because there is no effective medical or surgical therapy for most instances of sensorineural hearing loss, prevention is essential.
	• Situations where prevention is most likely to impact hearing outcomes are the prevention of noise-induced hearing loss and the prevention of drug ototoxicity.
	• Although at-risk subjects should use hearing protection, a significant proportion of at-risk workers use hearing protection either inconsistently or not at all.
	• Sound does not have to be annoying or painful to cause hearing loss over time.
	• Hearing protection should be worn if individuals find it necessary to raise their voice to carry on a conversation easily.
	• Precautions should be followed to minimize ototoxicity: (1) document preexisting hearing loss or vestibular dysfunction before prescribing vestibulotoxic or ototoxic medications; (2) administer aminoglycosides for no longer than 1 week; (3) avoid aminoglycosides in patients whose calculated creatinine clearance is less than 1.2 L/h; (4) monitor peak and trough aminoglycoside levels and adjust dosing accordingly; (5) use extended dosing intervals (such as once daily instead of multiple daily administration); (6) avoid combinations of aminoglycosides with other nephrotoxic or ototoxic drugs; (7) and discontinue ototoxic agents when clinical vestibulotoxicity or ototoxicity is detected.

There is no effective medical or surgical therapy for most instances of sensorineural hearing loss. Therefore, prevention is essential. The situations where prevention is most likely to impact hearing outcomes are the prevention of noise-induced hearing loss and the prevention of drug ototoxicity.

Unfortunately, present health promotion initiatives for hearing loss prevention are insufficient and are largely limited to the prevention of noise-induced hearing loss (16; 30; 134). Hearing protection should be used by at-risk subjects (eg, workers in heavy industry, foundry workers, textile industry workers, mill workers, heavy equipment operators, construction workers, machine operators and assemblers, bottling plant workers, soldiers and military aviators and aircrew, professional musicians and sound technicians, miners, farmers, and other agricultural workers, etc.). Unfortunately, a significant proportion of at-risk workers use hearing protection either inconsistently or not at all (100).

There is contradictory evidence that hearing loss prevention programs are effective in the long term (142). Low-quality evidence suggests that stricter legislation can reduce noise levels in workplaces, with substantial reductions demonstrated in some individual circumstances, but there are no controlled studies of the effectiveness of such measures in preserving hearing (142). The limited success of hearing loss prevention programs may be explained by limited use of hearing protection, suboptimal knowledge of noise as a hazard, workplace noisiness, and the benefits of hearing protection devices among some workers (111). Even when full-shift equivalent noise levels are well above the level at which hearing protection devices are required, usage rates are often quite low (32). Improvements are needed in implementing, reinforcing, and evaluating technical interventions and long-term effects. Education is critical because many affected individuals are reluctant to wear hearing protection, and many who wear it do not wear it consistently or correctly. If feasible, environmental controls should be placed to control noise exposure (30; 42). Concurrent with engineering controls, a range of hearing protection devices should be available free of charge, and hearing protection training should be reviewed, particularly for lower-skilled workers (111). Unfortunately, most companies give inadequate attention to environmental noise controls and instead rely primarily on hearing protectors to prevent hearing loss (30; 31). However, without noise controls at the source, exposed workers remain at unnecessary risk (31). Indeed, about two fifths of employees (38%) do not use hearing protectors routinely (30). Hearing protection use correlates with the completeness of company hearing protection programs, suggesting that underuse of hearing protection by employees is “in some substantial part, attributable to incomplete or inadequate company efforts” (30).

In an occupational setting, the Occupational Safety and Health Administration requires baseline and annual audiometric pure-tone air-conduction threshold testing of both ears at 500, 1000, 2000, 3000, 4000, and 6000 Hz for employees exposed to at least 50% of the permissible noise exposure level (OSHA Law and Regulations: 1910.95 Ocupational Noise Exposure). Testing is generally scheduled at least 14 hours after the employee's last noise exposure to minimize the effect of temporary threshold shifts; if this is not possible, employees should wear hearing protection until tested. If an employee's noise exposure exceeds the Occupational Safety and Health Administration’s permissible exposure level, employers may need to establish environmental controls to reduce noise, issue hearing protectors, or rotate employees to less noisy tasks for part of the work day. Some employers issue hearing protection even when the Occupational Safety and Health Administration standards are met because even at somewhat lower noise levels, some employees may develop permanent noise-induced hearing loss (102). A further complexity is that the Occupational Safety and Health Administration regulations do not cover a variety of workers exposed to excessive noise, including farmers, construction workers, and employees of small businesses where noise levels often exceed recommended levels.

Recreational noise exposure is usually less frequent and of shorter duration than occupational noise exposure, but it may compound occupational noise damage. Many power tools, lawnmowers, firearms, sound speakers, and personal listening devices (eg, MP3 players) exceed safe sound exposure levels. For example, approximate dBA sound levels are 90 for a lawnmower, 100 for a chainsaw, 120 for a rock concert, and 140 for a shotgun blast. The impulsive noise of firearms may be particularly damaging to the cochlea (125; 133). The main hearing loss-related risk factor for teenagers is exposure to recreational noise: frequent attendance at discotheques and pop-music concerts, use of personal stereos, and noise exposure in school workshops (85; 55; 45; 130; 132). Most students are unconcerned about potential effects of loud noise, and the use of hearing protection is minimal (less than 5%) (45).

Sound does not have to be annoying or painful to cause hearing loss over time. Hearing protection should be worn if individuals need to raise their voice to easily carry on a conversation. Hearing protection devices commonly available include ear muffs or earplugs. Ear muffs usually have higher noise-reduction ratings than earplugs; they can be worn in combination in extremely high noise environments, but the maximum noise reduction is approximately 50 dB because of bone conduction through the skull (102), and combination use of earplugs and earmuffs disrupts sound localization (122). Some individuals find ear muffs to be hot, cumbersome, or cosmetically unappealing, any of which can adversely affect usage (07). Training in earplug insertion is important for good attenuation (135). For difficult-to-fit external auditory canals, custom earplugs can be made from an earmold impression. Special earplugs are also available for special needs (eg, for cosmetic considerations, hunting, singing, band members, or specific work environments). In military situations, active noise cancellation earmuffs equipped for communication purposes seem to be the best protection for soldiers during military exercises (103). Misfit earplugs or earmuffs are much less effective and may not adequately protect hearing. Hearing aids (most of which are vented), cotton balls, and earplugs designed for swimming are all inadequate for hearing protection.

Whenever possible, the following precautions should be followed to minimize ototoxicity (20; 86; 136): (1) document preexisting hearing loss or vestibular dysfunction before prescribing vestibulotoxic or ototoxic medications; (2) administer aminoglycosides for no longer than 1 week; (3) avoid aminoglycosides in patients whose calculated creatinine clearance is less than 1.2 L/h; (4) monitor peak and trough aminoglycoside levels and adjust dosing accordingly; (5) use extended dosing intervals (such as once daily instead of multiple daily administration); (6) avoid combinations of aminoglycosides with other nephrotoxic or ototoxic drugs; (7) and discontinue ototoxic agents when clinical vestibulotoxicity or ototoxicity is detected. To avoid permanent impairment, aminoglycoside therapy should cease as soon as symptoms of either auditory or vestibular ototoxicity appear (51). If identified early, much of the symptomatic toxicity is reversible (150; 37; 14).

Specific medications may help prevent sensorineural hearing loss in specific populations. In type 2 diabetics, the use of statins is significantly associated with a 25% reduced risk of sensorineural hearing loss, regardless of age and sex (52). In obese hypertensive men (primarily middle-aged, white men), the use of calcium-channel blockers is associated with a 24% reduced risk of sensorineural hearing loss (131).

Differential diagnosis

Associated or underlying disorders

Congenital disorders include various genetic factors (including causes of otic capsule dysplasia syndromes and rare chromosomal syndromes), intrauterine infections (rubella, cytomegalovirus, herpes simplex, syphilis), and maternal drug or alcohol abuse (157). Genetic factors cause more than 50% of congenital hearing loss (13). Genetic hearing loss may be autosomal dominant, autosomal recessive, or X-linked.

Multiple conditions cause acquired sensorineural hearing loss after birth, including (1) infectious and postinfectious conditions (eg, COVID-19 [although very limited data are yet available], suppurative labyrinthitis, meningitis, measles, mumps [ie, epidemic parotitis], herpes zoster oticus [ie, Ramsay Hunt syndrome], and zika); (2) ototoxic drugs (eg, aminoglycosides [eg, tobramycin], loop diuretics [eg, furosemide], antimetabolites [eg, methotrexate], alkylating agents [eg, cisplatin], salicylates [eg, aspirin], proton pump inhibitors); (3) autoimmune factors (including Susac syndrome); (4) traumatic head injury (eg, inner ear concussion, perilymph fistula, shear injury of the eighth nerve, temporal bone fracture); (5) Meniere disease; (6) noise-induced cochlear injury; (7) vascular injury (labyrinthine infarction, superficial siderosis); (8) neoplastic and paraneoplastic conditions (eg, cerebellopontine angle tumors [eg, “acoustic neuroma” or vestibular schwannoma, and meningioma], carcinomatous meningitis, paraneoplastic subacute hearing loss or cochleovestibulopathy); (9) cranial radiation therapy; (10) nutritional disorders (eg, profound B-vitamin deficiencies); (11) intracranial hypertension; (12) sickle-cell disease; and (13) age-related changes (ie, presbycusis) (10; 101; 58; 88; 129; 143; 160). Diabetes and chronic obstructive pulmonary disease are also associated with an increased risk of sensorineural hearing loss, but the pathogenetic mechanisms are unclear (116; 120). Vitiligo is associated with an increased risk of sensorineural hearing loss, presumably indicating an autoimmune mechanism (79; 80).

Multiple conditions cause acquired sensorineural hearing loss after birth, including infectious and postinfectious conditions (eg, suppurative labyrinthitis, meningitis, measles, mumps [ie, epidemic parotitis], herpes zoster oticus [ie, Ramsay Hunt syndrome]), ototoxic drugs (eg, aminoglycosides [eg, tobramycin], loop diuretics [eg, furosemide], antimetabolites [eg, methotrexate], and salicylates [eg, aspirin]), autoimmune factors (including Susac syndrome), traumatic head injury (eg, inner ear concussion, perilymph fistula, shear injury of the eighth nerve, temporal bone fracture), Meniere disease, noise-induced cochlear injury, vascular injury (labyrinthine infarction, superficial siderosis), neoplastic and paraneoplastic conditions (eg, cerebellopontine angle tumors [eg, “acoustic neuroma” or vestibular schwannoma, and meningioma], carcinomatous meningitis, paraneoplastic subacute hearing loss or cochleovestibulopathy), cranial radiation therapy, nutritional disorders (eg, profound B-vitamin deficiencies, as seen in prisoners of war), and age-related changes (ie, presbycusis) (10; 101).

Subacute hearing loss with or without associated vestibular dysfunction can occur as a paraneoplastic condition in association with small-cell lung cancer, thymoma, neuroblastoma, and B-cell follicular lymphoma (87; 49; 39; 144; 113; 36; 59). In patients with paraneoplastic subacute hearing loss, the damage is generally cochlear or cochleovestibular. Some cases of subacute hearing loss may have anti-Hu antibodies (39; 59; 113) or glutamic acid decarboxylase autoantibody (144), but the antigens and antibodies involved in paraneoplastic cochleovestibulopathy remain unknown (49), and, consequently, the mechanism of paraneoplastic cochleovestibulopathy is not well understood.

Common causes of sensorineural hearing loss in the elderly include aging (ie, presbycusis), noise exposure, and vascular occlusive disease (43). Distinguishing among these various causes is facilitated by attention to history (eg, noise or toxin exposure, trauma, etc.), timing of onset and course of hearing loss, determination of whether the hearing loss is unilateral or bilateral, the distribution of hearing loss as a function of sound frequency, associated manifestations (eg, vertigo), and family history. Subjective tinnitus is often associated with sensorineural hearing loss, although the perceived abnormal sounds are generated centrally, probably at least in part by a “release” mechanism akin to that proposed for Bonnet visual hallucinations. Genetic factors contribute to a large proportion of late-onset cases of bilateral sensorineural hearing loss: in a Japanese study, potentially causative genetic variants were identified in 60% of the cases when genetic analysis of 63 known deafness genes was performed using massively parallel DNA sequencing (137).

Conditions that commonly produce cochlear sensorineural hearing loss include genetic disorders, intrauterine infections, infectious or postinfectious disorders, vascular damage or ischemia, noise exposure, ototoxicity, autoimmune disorders, Ménière disease, age-related changes (ie, presbycusis), and trauma. Causes of retrocochlear sensorineural hearing loss include superficial siderosis, some viral infections (eg, measles), meningitis, carcinomatous meningitis, internal auditory canal and cerebellopontine angle tumors, and head injury.

Diagnostic workup

	• The U.S. Preventive Services Task Force has concluded that current evidence is insufficient to assess the balance of benefits and harms of screening for hearing loss in asymptomatic adults aged 50 years or older without diagnosed hearing loss in the primary care setting.
	• Elderly individuals who complain of or acknowledge hearing impairment require audiometry, whereas those who deny hearing impairment should be screened with the whispered-voice test.
	• The Weber and Rinne tests should not be used for general screening.
	• Pure-tone audiometry (air and bone conduction) involves determination of the lowest intensity at which an individual hears a sequence of pure tones as a function of frequency (or pitch); specific frequencies from 250 (close to middle C) to 8000 Hz are tested using earphones and oscillators.
	• Patients with asymmetric sensorineural hearing loss may be followed with serial audiograms (every 6 months) if they have known significant asymmetric noise exposure, no recent changes in hearing or word recognition, and no associated symptoms or signs (eg, vertigo, hemiataxia).
	• Patients without a history of significant asymmetric noise exposure or other known cause of asymmetric sensorineural hearing loss as well as those with progression of asymmetric sensorineural hearing loss should undergo brainstem auditory-evoked potential testing.
	• MRI imaging is not a cost-effective screening technique for acoustic neuroma among all patients with asymmetric sensorineural hearing loss.
	• MRI should be reserved for cases with a high clinical suspicion or cases with abnormal or inconclusive results from brainstem auditory-evoked potential testing.
	• The “rule 3000” is a clinical decision rule that can help guide a more cost-effective approach to utilization of MRI in patients with asymmetric sensorineural hearing loss: if asymmetric sensorineural hearing loss of at least 15 dB is present at 3000 Hz, MRI should be performed; in contrast, if there is less than 15 dB of asymmetry at this frequency, patients can be followed biannually with audiometry.
	• MRI is also recommended to evaluate congenital total hearing loss, as this may aid in identifying and classifying inner ear abnormalities, determining contraindications to cochlear implantation, and predicting intraoperative difficulties in those considered candidates for cochlear implantation.
	• A stepwise diagnostic approach, including imaging, genetic testing, and pediatric evaluation can identify a cause for sensorineural hearing loss in two thirds of affected children.

The U.S. Preventive Services Task Force has concluded that current evidence is insufficient to assess the balance of benefits and harms of screening for hearing loss in asymptomatic adults aged 50 years or older without diagnosed hearing loss in the primary care setting (97). Elderly individuals who complain of or acknowledge hearing impairment require audiometry, whereas those who deny hearing impairment should be screened with the whispered-voice test (09). With the whispered voice test, the examiner whispers a set of three random numbers and letters while gently using the end of his or her finger to occlude and rub the external auditory canal of the patient’s nontested ear (rubbing is necessary because occlusion of the external auditory canal does not provide sufficient masking) (09). The whispered voice test should be performed with the examiner either standing behind the patient or with the patient’s eyes closed to prevent lip-reading. To ensure that the patient understands the instructions, a trial run using a loud voice is recommended. Individuals who perceive the whispered voice do not require further testing, whereas those unable to perceive the whispered voice require audiometry (09). The Weber and Rinne tests should not be used for general screening.

Distinguishing among the various causes of sensorineural hearing loss is facilitated by attention to history (eg, family history of hearing impairment, exposures during pregnancy for congenital cases, age of onset, noise or toxin exposure, trauma, etc.), onset (eg, sudden, subacute, or chronic), course (eg, static, fluctuating, or progressive), determination of whether the hearing loss is unilateral or bilateral, the pattern or profile of hearing loss (ie, distribution of hearing loss as a function of sound frequency), and associated manifestations (eg, vertigo, ataxia, etc.).

Audiometry subjectively determines how the individual processes auditory information; consequently, audiometry requires patient cooperation and the ability to communicate effectively concerning auditory perceptions of presented acoustic stimuli. Pure-tone audiometry (air and bone conduction) involves determination of the lowest intensity at which an individual hears a sequence of pure tones as a function of frequency (or pitch). Specific frequencies from 250 (close to middle C) to 8000 Hz are tested using earphones and oscillators. Intensity or loudness is measured in decibels (dB), which is a logarithmic unit used to describe the ratio of two sound pressures, where the reference threshold is the average threshold for a normal-hearing adult. The audiogram is a graphic profile of hearing thresholds (in dB hearing level) as a function of frequency (in Hz). The pattern of auditory thresholds as a function of frequency shown on an audiogram is helpful diagnostically; for example, a low-frequency pattern of sensorineural hearing loss is typical of Ménière disease, Wolfram syndrome, and Susac syndrome; a sloping high-frequency hearing loss pattern is typical of presbycusis, and a notched pattern (with the notch at 4 kHz) is typical of noise-induced hearing loss. Audiologists use special behavioral techniques to test hearing in infants and young children.

Sensorineural hearing loss, low-frequency trough pattern

Audiogram showing a low-frequency trough pattern of sensorineural hearing loss, commonly seen in Meniere disease. The left ear is shown. (Courtesy of James Lanska.)
Sensorineural hearing loss, sloping pattern

Audiogram showing symmetric gradually sloping high-frequency sensorineural hearing loss. The right ear is shown. (Courtesy of James Lanska.)
Sensorineural hearing loss, notched pattern

Audiogram showing a “4 kHz notch” (or colloquially a “4K notch”) pattern of sensorineural hearing loss commonly seen in noise-induced hearing loss. Both ears are shown. (Courtesy of James Lanska.)

Speech audiometry tests include assessment of speech reception thresholds, speech detection thresholds, and word recognition (19). The speech reception threshold is the lowest intensity level at which a patient can correctly repeat half of a series of common bisyllabic words from a closed set that are spoken with equal emphasis on both syllables (so-called “spondee” words, like “baseball,” “airplane,” and “playground”), preferably using recorded materials rather than monitored live voice (ie, spoken by the audiologist, processed, and presented at a specific intensity). The speech reception threshold should correspond closely to the pure-tone average: assuming that a patient fully understands the audiologist’s directions, a speech reception threshold substantially better than the pure-tone average suggests possible malingering or exaggeration of hearing loss whereas a speech reception threshold that is substantially worse than the pure-tone average may indicate hearing loss with severe distortion of speech sounds (19). In certain circumstances (eg, when a patient has difficulty understanding speech or is hesitant to guess when uncertain), the audiologist may use a limited set of test words that are first practiced with the patient; in this situation, the speech reception threshold more closely approximates the threshold of the best component frequency used in the computation of the pure-tone average rather than the pure-tone average itself (19). When speech reception threshold cannot be measured (as in infants), speech detection threshold may be used instead: speech detection threshold is the lowest intensity level at which a patient can detect the presence of speech, and it generally corresponds to the best test frequency threshold (19). Word recognition (or “speech discrimination”) measures a patient’s ability to repeat a list of monosyllabic words at a suprathreshold level (approximately 40 dB above the speech reception threshold or at a comfortable listening level if this is too loud for the patient) (19).

Physiologic tests of the auditory system can objectively determine the functional status of the auditory system and can be performed at any age. Such tests include immittance testing, evoked otoacoustic emissions, and brainstem auditory evoked response testing (also known as auditory brainstem response testing). Immittance testing (ie, tympanometry, acoustic reflex thresholds, and acoustic reflex decay) is used to assess middle ear pressure, tympanic membrane mobility, Eustachian tube function, mobility of the middle ear ossicles, and the function of the acoustic reflex pathway. Evoked otoacoustic emissions are sounds originating within the cochlea as a manifestation of the activity of the cochlear outer hair cells; evoked otoacoustic emissions are present in ears with hearing sensitivity better than 40 to 50 dB hearing level and are measured using an external-auditory-canal probe with a microphone and transducer. Brainstem auditory evoked response or auditory brainstem response testing uses a series of clicks to evoke electrophysiologic responses in the eighth cranial nerve and auditory brainstem, which are recorded with surface electrodes. The auditory brainstem response wave V detection threshold can be used to estimate auditory thresholds in patients who cannot cooperate (eg, young children, and aphasic or demented patients) or will not cooperate (eg, malingering patients) with behavioral tests such as pure-tone audiometry. Because broadband click or tone burst stimuli are needed to elicit sufficient neural synchrony for an observable response with auditory brainstem response threshold estimation, this technique cannot be used to provide a frequency profile of hearing as in an audiogram (19). The auditory brainstem response wave V detection threshold does not assess low frequency (lower than 1500 Hz) auditory sensitivity but instead correlates roughly with hearing sensitivity in the range from 1500 to 4000 Hz. Nevertheless, auditory brainstem response threshold estimation does not measure hearing per se, and such thresholds may be normal even in the absence of the auditory cortex when sound perception is obviously impossible (19).

Ancillary testing (eg, videonystagmography or electronystagmography, vestibular-evoked myogenic potentials, magnetic resonance imaging, temporal bone CT, and molecular genetic testing) is helpful in selected cases, including some cases with congenital hearing loss or acquired asymmetric sensorineural hearing loss. In general cases with acquired symmetric sensorineural hearing loss, in the absence of other manifestations (eg, vestibular or central nervous system signs or symptoms), do not require ancillary testing.

Patients with asymmetric sensorineural hearing loss may be followed with serial audiograms (every 6 months) if they have known significant asymmetric noise exposure, no recent changes in hearing or word recognition, and no associated symptoms or signs (eg, vertigo, hemiataxia) (138). Patients without a history of significant asymmetric noise exposure or other known cause of asymmetric sensorineural hearing loss as well as those with progression of asymmetric sensorineural hearing loss should undergo brainstem auditory-evoked potential testing (138).

MRI imaging is not a cost-effective screening technique for acoustic neuroma among all patients with asymmetric sensorineural hearing loss (66). Among young adult men receiving screening audiometry as military recruits, only 0.3% had asymmetric sensorineural hearing loss, and only 0.3% of these had a causative intracranial lesion, none of whom had a vestibular schwannoma (66). One patient had an enlarged vestibular aqueduct, and the other patient had asymmetric prominence of the cisternal portion of the eighth cranial nerve without contrast enhancement of unclear basis. MRI should be reserved for cases with a high clinical suspicion or cases with abnormal or inconclusive results from brainstem auditory-evoked potential testing (138). Various prediction rules have been proposed (115; 03; 27). The “rule 3000” is a clinical decision rule that can help guide a more cost-effective approach to utilization of MRI in patients with asymmetric sensorineural hearing loss--if asymmetric sensorineural hearing loss of at least 15 dB is present at 3000 Hz, MRI should be performed; in contrast, if there is less than 15 dB of asymmetry at this frequency, patients can be followed biannually with audiometry (115; 03).

MRI has also been recommended in the evaluation of congenital total hearing loss, as this may aid in identifying and classifying inner ear abnormalities, determining contraindications to cochlear implantation, and predicting intraoperative difficulties in those considered candidates for cochlear implantation (29; 141). Inner ear abnormalities were found by MRI in 20% to 40% of imaged ears among patients with congenital profound or total deafness (29; 141).

However, although both CT and MRI have important and often complementary diagnostic utility, in a multi-institutional retrospective chart review of patients under 18 years of age, CT had superior diagnostic yield in identifying abnormalities associated with bilateral sensorineural hearing loss (162). In this study, approximately a quarter of the 313 patients had an abnormal finding on CT or MRI. The concordance rate was 92%. The diagnostic yield of CT and MRI were 25% and 18%, respectively. CT was significantly more likely to yield an abnormal finding versus MRI. The most common findings on CT were cochlear and semicircular canal abnormalities, whereas the most common findings on MRI were cochlear nerve aplasia/hypoplasia and semicircular canal abnormalities.

Higher rates of abnormalities are identified by CT and MR imaging in children with profound hearing loss (approximately 40%) compared to milder hearing loss approximately 10% to 30%), and in asymmetric sensorineural hearing loss (approximately 50%) compared to symmetric sensorineural hearing loss (approximately 30%) (141). In one study of pediatric unilateral sensorineural hearing loss patients who underwent CT of the temporal bone, MRI, or both as part of their clinical work-up, uniform criteria for pursuing imaging were not employed, but even in this grab sample (obtained from a multiinstitutional retrospective chart review at tertiary medical centers) there was a significant yield of abnormalities detected by CT or MRI—40% of 2019 had abnormalities identified by CT of the temporal bone, MRI, or both (119); almost all of these were results of optic capsule dysplasia, most commonly enlarged vestibular aqueduct and cochlear abnormalities (eg, cochlear nerve aplasia or hypoplasia) (119).

When superficial siderosis is suspected, a thorough evaluation is necessary to localize the source of bleeding. MRI is the most important diagnostic study in conjunction with lumbar puncture and selective use of angiography. Although CT may suggest the diagnosis of superficial siderosis, MRI is more sensitive and specific (127; 17; 69). Although used in the past (152), there is little role for brain biopsy any longer to diagnose this condition. Nevertheless, even with thorough diagnostic evaluation, the source of bleeding remains unidentified in many cases (92; 69). When superficial siderosis is diagnosed on brain imaging and no source is identified, spinal imaging is essential (78; 48).

A stepwise diagnostic approach, including imaging, genetic testing, and pediatric evaluation, can identify a cause for sensorineural hearing loss in two thirds of affected children (140). If sensorineural hearing loss is diagnosed within the first 3 weeks after birth, cytomegalovirus (CMV) testing should be performed to identify patients that may benefit from antiviral treatment (67). If sensorineural hearing loss is diagnosed in an infant after 3 weeks, testing can be done using dried blood spots samples, if testing capability is available. In children with bilateral sensorineural hearing loss, genetic testing should be performed, ideally with next generation sequencing techniques. Ophthalmological evaluation must be done on all children with sensorineural hearing loss. High-resolution CT and/or MRI should be performed to assess for anatomic causes of hearing loss and to determine candidacy for cochlear implantation when indicated. In a study of 423 children with sensorineural hearing loss, the most commonly identified cause among those with bilateral sensorineural hearing loss was a genetic mutation (26%), whereas among those with unilateral sensorineural hearing loss, the most commonly identified cause was a structural anomaly of the temporal bone (27%) (140). The probability of finding an etiologic diagnosis is significantly higher in children under 1 year of age and in children with profound sensorineural hearing loss (140).

Genetic tests are available for only a subset of the recognized causes of genetic hearing loss, including some with a high frequency as a cause of deafness (ie, mutations in GJB2 with DFNB1B), some associated with another recognizable clinical or radiological feature (ie, SLC26A4 and Pendred syndrome [OMIM 274600] and enlarged vestibular aqueduct), and some associated with a recognizable audiogram profile (eg, WFS1 with low-frequency sensorineural hearing loss in Wolfram syndrome I). One retrospective chart review of 430 pediatric patients with nonsyndromic sensorineural hearing loss at a tertiary pediatric hospital found that some genetic testing was ordered in 28% of cases, and comprehensive genetic testing was ordered in 25% of cases (112). Of those with comprehensive genetic testing, a definitive genetic etiology was identified in only 12%.

Sensorineural hearing loss associated with nonsyndromic large vestibular aqueduct syndrome has been localized to 7q31 and results from recessive mutations in the anion transporter gene SLC26A4 responsible for many cases of Pendred syndrome (01; 139; 18; 15; 158; 08; 159; 105; 110; 23; 123). SLC26A4 codes for pendrin, a membrane transporter that can exchange anions between the cytosol and the extracellular fluid (105). Both Pendred syndrome and nonsyndromic hearing loss associated with an enlarged vestibular aqueduct can also result from disruption of the transcriptional control of SLC26A4, either by interfering with a key transcriptional element in the SLC26A4 promoter that binds FOX11 (a transcriptional activator of SCL26A4) or by mutations in FOX11 itself (159). Considerable phenotypic variability exists among patients with biallelic SLC26A4 mutations, but the basis for this variability is unknown and may relate to modifier genes or environmental factors (123). Wolfram syndrome (WFS1; OMIM 222300) is an autosomal-recessive allelic disorder characterized by optic atrophy, diabetes mellitus, hearing loss, and diabetes insipidus; it is caused by homozygous or compound heterozygous mutations in the WFS1 gene on chromosome 4p16.1.

Management

	• Healthcare professionals and family members can improve communication with affected patients by facing the person (so that the impaired person can easily see face and lip movements), speaking in a lower register with short simple sentences, and eliminating extraneous background sounds when possible.
	• Hearing aids are the principal form of rehabilitation for sensorineural hearing loss and can significantly improve communication and reduce hearing handicap.
	• Hearing aids are effective for treating mild to moderate hearing loss when the device is appropriately selected and fit for the patient and when the patient is motivated and able to use the device.
	• Even in demented patients, hearing aids are generally well tolerated and reduce disability caused by hearing impairment, so dementia per se is not a reason to preclude evaluation for a hearing aid; however, hearing aids do not reduce cognitive dysfunction, behavioral problems, or psychiatric manifestations in such patients.
	• Assistive devices and training in “speech-reading” are helpful for many elderly patients with presbycusis and other forms of sensorineural hearing loss.
	• Instruction in sign language should be considered for those with severe hearing loss not corrected by a hearing aid.
	• Cochlear implantation may improve audiologic performance and quality of life, including among elderly patients, even into their eighties.

Healthcare professionals and family members can improve communication with affected patients by facing the person (so that the impaired person can easily see face and lip movements), speaking in a lower register with short, simple sentences, and eliminating extraneous background sounds when possible. Hearing aids are the principal form of rehabilitation for sensorineural hearing loss and can significantly improve communication and reduce hearing handicap (154; 44).

Hearing aids are effective for treating mild to moderate hearing loss when the device is appropriately selected and fit for the patient and when the patient is motivated and able to use the device. Even in demented patients, hearing aids are generally well tolerated and reduce disability caused by hearing impairment, so dementia per se is not a reason to preclude evaluation for a hearing aid; however, hearing aids do not reduce cognitive dysfunction, behavioral problems, or psychiatric manifestations in such patients (05). Patients generally require a period of acclimatization to hearing aid use, which is associated with an apparent gain in the signal-to-noise ratio and lower cognitive load required for use (90).

In addition, assistive devices (eg, a built-in telephone amplifier, low-frequency doorbells, amplified ringers, close-captioned television decoders, flashing alarm clocks, flashing smoke detectors, and alarm bed vibrators) and training in “speech-reading” (ie, using visual cues to help determine what is being spoken) are helpful for many elderly patients with presbycusis and other forms of sensorineural hearing loss (44; 154).

Instruction in sign language should be considered for those with severe hearing loss not corrected by a hearing aid. For selected patients with profound hearing loss that is not improved by a simple hearing aid, a cochlear implant device may provide functional hearing (101); there is no absolute age threshold beyond when this procedure cannot be done for appropriate patients.

Cochlear implantation may improve audiologic performance and quality of life, including among elderly patients, even into their eighties (70; 33; 124; 61). Pain and transient vertigo are the most common complications reported in elderly patients following cochlear implantation (33).

In children, guidelines for cochlear implantation require the following:

“(1) bilateral profound bilateral sensorineural hearing loss in children aged 9 to 24 months and bilateral severe to profound sensorineural hearing loss in children older than 2 years; (2) use of appropriately fitted hearing aids for 3 months (this can be waived if there is evidence of ossification); and (3) demonstration of limited progress with auditory, speech, and language development" (06).

Speech and language measures and health-related quality of life can improve in children undergoing unilateral cochlear implantation for asymmetric sensorineural hearing loss (84) and also apparently for cochlear implantation in children with unilateral sensorineural hearing loss (161), although a wider experience will be necessary before this should influence management guidelines.

Targeted management of the underlying etiology may be necessary in a small fraction of patients with sensorineural hearing loss, including some patients with barotrauma, traumatic brain injury, acoustic trauma (ie, exposure to excessively loud noise), sudden sensorineural hearing loss, progressive asymmetric sensorineural hearing loss (which may represent the effects of a tumor of the eighth cranial nerve or some other cerebellopontine angle mass), subacute bilateral progressive sensorineural hearing loss (which may represent autoimmune inner ear disease), and fluctuating sensorineural hearing loss (which may represent Meniere disease, especially in association with subjective tinnitus, aural fullness, and vertigo). Meniere disease may be treated medically with a low-sodium diet, diuretics, and corticosteroids, but if the vertigo is not medically controlled, various surgical procedures may be considered. Sensorineural hearing loss either from tumors of the eighth nerve or compressing the eighth nerve generally is not reversed with surgical removal or irradiation; if the hearing loss is mild and the tumor is very small, hearing may be saved in 50% of those undergoing hearing preservation surgery for tumor removal.

References

01: Abe S, Usami S, Hoover DM, Cohn E, Shinkawa H, Kimberling WJ. Fluctuating sensorineural hearing loss associated with enlarged vestibular aqueduct maps to 7q31, the region containing the Pendred gene. Am J Med Genet 1999;82:322-8. PMID 10051166
02: Agrawal Y, Platz EA, Niparko JK. Prevalence of hearing loss and differences by demographic characteristics among US adults: data from the National Health and Nutrition Examination Survey, 1999-2004. Arch Intern Med 2008;168(14):1522-30. PMID 18663164
03: Ahsan SF, Standring R, Osborn DA, Peterson E, Seidman M, Jain R. Clinical predictors of abnormal magnetic resonance imaging findings in patients with asymmetric sensorineural hearing loss. JAMA Otolaryngol Head Neck Surg 2015;141(5):451-6. PMID 25719460
04: Al-Achkar W, Al-Halabi B, Ali B, Moassass F. First report of prevalence c.IVS1+1G>A and del (GJB6-13S1854) mutations in Syrian families with non-syndromic sensorineural hearing loss. Int J Pediatr Otorhinolaryngol 2017;92:82-7. PMID 28012540
05: Allen NH, Burns A, Newton V, et al. The effects of improving hearing in dementia. Age Aging 2003;32:189-93. PMID 12615563
06: Anne S, Brown KD, Goldberg DM, et al. Pediatric bilateral sensorineural hearing loss: minimum test battery and referral criteria for cochlear implant candidacy evaluation. Otolaryngol Head Neck Surg 2022;166(3):405-9. PMID 34281450
07: Arezes PM, Miguel AS. Hearing protectors acceptability in noisy environments. Ann Occup Hyg 2002;46(6):531-6. PMID 12176768
08: Azaiez H, Yang T, Prasad S, et al. Genotype-phenotype correlations for SLC26A4-related deafness. Hum Genet 2007;122(5):451-7. PMID 17690912
09: Bagai A, Thavendiranathan P, Detsky AS. Does this patient have hearing impairment. JAMA 2006;295(4):416-28.** PMID 16434632
10: Bass JK, Hua CH, Huang J, et al. Hearing loss in patients who received cranial radiation therapy for childhood cancer. J Clin Oncol 2016;34(11):1248-55. PMID 26811531
11: Bekesy G. Experiments in Hearing. Translated and edited by E.G. Wever. Acoustical Society of America. New York: McGraw Hill Book Co., 1960.
12: Bekesy G. Concerning the pleasures of observing, and the mechanics of the inner ear: Nobel Lecture, December 11, 1961. In: Nobel Lectures, Physiology or Medicine 1942-1962. Amsterdam: Elsevier Publishing Company, 1964:722-45.
13: Bilavsky E, Shahar-Nissan K, Pardo J, Attias J, Amir J. Hearing outcome of infants with congenital cytomegalovirus and hearing impairment. Arch Dis Child 2016;101(5):433-8. PMID 26826174
14: Black FO, Peterka, RJ, Elardo SM. Vestibular reflex changes following aminoglycoside-induced ototoxicity. Laryngoscope 1987;97:582-6. PMID 3573904
15: Blons H, Feldmann D, Duval V, et al. Sceening of SLC26A4 (PDS) gene in Pendred’s syndrome: a large spectrum of mutations in France and phenotypic heterogeneity. Clin Genet 2004;66:333-40. PMID 15355436
16: Borchgrevink HM. Does health promotion work in relation to noise. Noise Health 2003;5(18):25-30. PMID 12631433
17: Bracchi M, Savoiardo M, Triulzi F, et al. Superficial siderosis of the CNS: MR diagnosis and clinical findings. Am J Neuroradiol 1993;14:227-36. PMID 8427096
18: Campbell C, Cucci RA, Prasad S, Green GE. Pendred syndrome, DFNB4, and PDS/SLC26A4: identification of eight novel mutations and possible genotype-phenotype correlations. Hum Mutat 2001;17:403-11. PMID 11317356
19: Campbell K. Essential Audiology for Physicians. San Diego & London: Singular Publishing Group, 1998.**
20: Campbell KC, Durrant J. Audiologic monitoring for ototoxicity. Otolaryngol Clin North Am 1993;26:903-14. PMID 8233496
21: Campbell VA, Crews JE, Moriarity DG, Zack MM, Blackman DK. Surveillance for sensory impairment, activity limitation, and health-related quality of life among older adults. Surveillance for selected public health indicators affecting older adults – United States, 1993-1997. MMWR CDC Surveill Summ 1999;48(8):131-56. PMID 10634273
22: Carney LH. Spatiotemporal encoding of sound level: models for normal encoding and recruitment of loudness. Hear Res 1994;76:31-44. PMID 7928712
23: Chen K, Wang X, Sun L, Jiang H. Screening of SLC26A4, FOXI1, KCNJ10, and GJB2 in bilateral deafness patients with inner ear malformation. Otolaryngol Head Neck Surg 2012;146(6):972-8. PMID 22412181
24: Chien HW, Wu PH, Wang K, et al. Increased incidence of glaucoma in sensorineural hearing loss: a population-based cohort study. Int J Environ Res Public Health 2019;16(16). PMID 31416136
25: Chung DY, Mason K, Gannon RP, Willson GN. The ear effect as a function of age and hearing loss. J Acoust Soc Am 1983;73:1277-82. PMID 6853839
26: Clark JG. Uses and abuses of hearing loss classification. ASHA 1981;23:493-500.** PMID 7052898
27: Conley M, Diaz RC. Asymmetric sensorineural hearing loss and vestibular schwannoma: when to image? Curr Opin Otolaryngol Head Neck Surg 2020;28(5):335-9. PMID 32841960
28: Cooper AF, Curry AR, Kay DW, Garside RF, Roth M. Hearing loss in paranoid and affective psychoses of the elderly. Lancet 1974;2(7885):851-4. PMID 4137694
29: Dagkiran M, Dagkiran N, Surmelioglu O, et al. Radiological imaging findings of patients with congenital totally hearing loss. J Int Adv Otol 2016;12(1):43-8. PMID 27340982
30: Daniell WE, Swan SS, McDaniel MM, Camp JE, Cohen MA, Stebbins JG. Noise exposure and hearing loss prevention programmes after 20 years of regulations in the United States. Occup Environ Med 2006;63(5):343-51. PMID 16551755
31: Davies H, Marion S, Teschke K. The impact of hearing conservation programs on incidence of noise-induced hearing loss in Canadian workers. Am J Ind Med 2008;51(12):923-31. PMID 18726988
32: Edelson J, Neitzel R, Meischke H, et al. Predictors of hearing protection use in construction workers. Ann Occup Hyg 2009;53(6):605-15. PMID 19531807
33: Eshraghi AA, Rodriguez M, Balkany TJ, et al. Cochlear implant surgery in patients more than seventy-nine years old. Laryngoscope 2009;119:1180-3. PMID 19301411
34: Eustachii B. Tabulae anatomicae. Rome: Francisci Gonzagae, 1714.
35: Eustachii B. Tabulae anatomicae. Rome: Pauli Junchi, 1783.
36: Evoli A, Minicuci GM, Vitaliani R, et al. Paraneoplastic diseases associated with thymoma. J Neurol 2007;254(6):756-62. PMID 17325820
37: Fee WE Jr. Aminoglycoside ototoxicity in the human. Laryngoscope 1980;90:1-19. PMID 7432055
38: Fettiplace R. Active hair bundle movements in auditory hair cells. J Physiol 2006;576:29-36. PMID 16887874
39: Fisher PG, Wechsler DS, Singer HS. Anti-Hu antibody in a neuroblastoma-associated paraneoplastic syndrome. Pediatr Neurol 1994;10(4):309-12. PMID 8068157
40: Fraser GR. Profound childhood deafness. J Med Genet 1964;1:118-51. PMID 14234108
41: Gadsboll E, Erbs AW, Hougaard DD. Prevalence of abnormal vestibular responses in children with sensorineural hearing loss. Eur Arch Otorhinolaryngol 2022;279(10):4695-707. PMID 35156132
42: Gates DM, Jones MS. A pilot study to prevent hearing loss in farmers. Public Health Nurs 2007;24:547-53. PMID 17973732
43: Gates GA, Cobb JL, D'Agostino RB, Wolf PA. The relation of hearing in the elderly to the presence of cardiovascular disease and cardiovascular risk factors. Arch Otolaryngol Head Neck Surg 1993;119:156-61. PMID 8427676
44: Gates GA, Rees TS. Hear ye? Hear ye! Successful auditory aging. West J Med 1997;167(4):247-52. PMID 9348755
45: Gilles A, Van Hal G, De Ridder D, Wouters K, Van de Heyning P. Epidemiology of noise-induced tinnitus and the attitudes and beliefs towards noise and hearing protection in adolescents. PLoS One 2013;8(7):e70297. PMID 23894638
46: Gillespie PG, Müller U. Mechanotransduction by hair cells: models, molecules, and mechanisms. Cell 2009;139:33-44. PMID 19804752
47: Goldstein DP. Hearing impairment, hearing aids and audiology. ASHA 1984;26:24-35, 38.** PMID 6487402
48: Gonella MC, Fischbein NJ, Lane B, Shuer LM, Greicius MD. Episodic encephalopathy due to an occult spinal vascular malformation complicated by superficial siderosis. Clin Neurol Neurosurg 2010;112(1):82-4. PMID 19857921
49: Gulya AJ. Neurologic paraneoplastic syndromes with neurotologic manifestations. Laryngoscope 1993;103(7):754-61. PMID 8341101
50: Halliday LF, Tuomainen O, Rosen S. Language development and impairment in children with mild to moderate sensorineural hearing loss. J Speech Lang Hear Res 2017;60(6):1551-67. PMID 28547010
51: Halmagyi GM, Fattore CM, Curthoys IS, Wade S. Gentamicin vestibulotoxicity. Otolaryngol Head Neck Surg 1994;111:571-4. PMID 7970794
52: Han HW, Yee J, Park YH, Gwak HS. Association between statin use and sensorineural hearing loss in type 2 diabetic patients: a hospital-based study. Pharmaceuticals (Basel) 2021;14(11):1076. PMID 34832858
53: Hazen M, Cushing SL. Vestibular evaluation and management of children with sensorineural hearing loss. Otolaryngol Clin North Am 2021;54(6):1241-51. PMID 34774232
54: Helmholtz HL. On the sensations of tone as a physiological basis for the theory of music (Translated by A.J. Ellis). London: Longmans, Green, & Co., 1885.
55: Henderson E, Testa MA, Hartnick C. Prevalence of noise-induced hearing-threshold shifts and hearing loss among US youths. Pediatrics 2011;127(1):e39-46. PMID 21187306
56: Hilgert N, Smith RJ, Van Camp G. Forty-six genes causing nonsyndromic hearing impairment: Which ones should be analyzed in DNA diagnostics. Mutat Res 2009a;681:189-96. PMID 18804553
57: Hilgert N, Smith RJ, Van Camp G. Function and expression pattern of nonsyndromic deafness genes. Curr Mol Med 2009b;9(5):546-64. PMID 19601806
58: Huang X, Jia Y, Jiao L. Sensorineural hearing loss as the prominent symptom in meningeal carcinomatosis. Curr Oncol 2021;28(5):3240-50. PMID 34449589
59: Hudhud KH, Masood A, Oh Y, Hegazi A. Neurocognitive deficits in a patient with small cell lung cancer: a case report. Cases J 2008;1(1):278. PMID 18954460
60: Hudspeth AJ. Making an effort to listen: mechanical amplification in the ear. Neuron 2008;59:530-45. PMID 18760690
61: Huinck WJ, Mylanus EAM, Snik AFM. Expanding unilateral cochlear implantation criteria for adults with bilateral acquired severe sensorineural hearing loss. Eur Arch Otorhinolaryngol 2019;276(5):1313-20. PMID 30810818
62: Iwasa YI, Nishio SY, Sugaya A, et al. OTOF mutation analysis with massively parallel DNA sequencing in 2,265 Japanese sensorineural hearing loss patients. PLoS One 2019;14(5):e0215932. PMID 31095577
63: Jecmenica J, Bajec-Opančina A, Ječmenica D. Genetic hearing impairment. Childs Nerv Syst 2015;31(4):515-9. PMID 25686889
64: Jones EM, White AJ. Mental health and acquired hearing impairment: a review. Br J Audiol 1990;24(1):3-9. PMID 2180515
65: Kazmierczak P, Müller U. Sensing sound: molecules that orchestrate mechanotransduction by hair cells. Trends Neurosci 2012;35:220-9. PMID 22177415
66: Khan HZ, Park CY, Lim MA, et al. Radiographic findings in young adults with asymmetric sensorineural hearing loss. Am J Otolaryngol 2019;40(1):78-82. PMID 30472122
67: Kilic S, Bouzaher MH, Cohen MS, Lieu JEC, Kenna M, Anne S. Comprehensive medical evaluation of pediatric bilateral sensorineural hearing loss. Laryngoscope Investig Otolaryngol 2021;6(5):1196-207. PMID 34667865
68: Kim BJ, Kim AR, Lee C, et al. Discovery of CDH23 as a significant contributor to progressive postlingual sensorineural hearing loss in Koreans. PLoS One 2016;11(10):e0165680. PMID 27792758
69: Kumar N, McKeon A, Rabinstein AA, Kalina P, Ahlskog JE, Mokri B. Superficial siderosis and CSF hypovolemia: the defect (dural) in the link. Neurology 2007;69(9):925-6. PMID 17724297
70: Kunimoto M, Yamanaka N, Kimura T, et al. The benefit of cochlear implantation in the Japanese elderly. Auris Nasus Larynx 1999;26:131-7. PMID 10214890
71: Lanska DJ. Georg von Bekesy. In: Aminoff MJ, Daroff RB, editors. Encyclopedia of the Neurological Sciences. 2nd ed. Oxford: Academic Press/Elsevier, 2014a;1:403-4.
72: Lanska DJ. Hermann von Helmholtz. In: Aminoff MJ, Daroff RB, editors. Encyclopedia of the Neurological Sciences. 2nd ed. Oxford: Academic Press/Elsevier, 2014b;2:539-40.
73: Lanska DJ. Jean-Marc Gaspard Itard. In: Aminoff MJ, Daroff RB, editors. Encyclopedia of the Neurological Sciences. 2nd ed. Oxford: Academic Press/Elsevier, 2014c;2:765-6.
74: Lanska DJ. Prosper Ménière. In: Aminoff MJ, Daroff RB, editors. Encyclopedia of the Neurological Sciences. 2nd ed. Oxford: Academic Press/Elsevier, 2014d;2:1055-6.
75: Lanska DJ. Disorders of the special senses in the elderly. In: Nair A, Sabbagh M, editors. Geriatric Neurology. Chichester, West Sussex, UK: John Wiley & Sons, 2014e:396-459.**
76: Lanska JR, Lanska DJ. Andreas Vesalius. In: Aminoff MJ, Daroff RB, editors. Encyclopedia of the Neurological Sciences. 2nd ed. Oxford: Academic Press/Elsevier, 2014;4:638-9.
77: LeMasurier M, Gillespie PG. Hair-cell mechanotransduction and cochlear amplification. Neuron 2005;48:403-15. PMID 16269359
78: Lemmerling M, De Praeter G, Mollet P, et al. Secondary superficial siderosis of the central nervous system in a patient presenting with sensorineural hearing loss. Neuroradiology 1998;40:312-4. PMID 9638673
79: Li CL, Ma SH, Wu CY, Chang PH, Chang YT, Wu CY. Association between sensorineural hearing loss and vitiligo: a nationwide population-based cohort study. J Eur Acad Dermatol Venereol 2022;36(7):1097-103. PMID 35274365
80: Lien KH, Ger TY, Chi CC. Association of vitiligo with high-frequency sensorineural hearing loss: a systematic review and meta-analysis. J Eur Acad Dermatol Venereol 2022;36(3):373-9. PMID 34779053
81: Lin FR, Niparko JK, Ferrucci L. Hearing loss prevalence in the United States. Arch Intern Med 2011;171(20):1851-2. PMID 22083573
82: Luo J, Bai X, Zhang F, et al. Prevalence of mutations in deafness-causing genes in cochlear implanted patients with profound nonsyndromic sensorineural hearing loss in Shandong Province, China. Ann Hum Genet 2017;81(6):258-66. PMID 28786104
83: Mahomva C, Kim A, Lieu JEC, Goldberg DM, Anne S. Speech and language outcomes in mild-moderate unilateral sensorineural hearing loss. Int J Pediatr Otorhinolaryngol 2021;141:110558. PMID 33340985
84: Malhotra PS, Densky J, Melachuri M, et al. The impact of cochlear implantation on speech and language outcomes in children with asymmetric sensorineural hearing loss. Int J Pediatr Otorhinolaryngol 2022;152:110979. PMID 34844163
85: Martinez-Wbaldo Mdel C, Soto-Vázquez C, Ferre-Calacich I, Zambrano-Sánchez E, Noguez-Trejo L, Poblano A. Sensorineural hearing loss in high school teenagers in Mexico City and its relationship with recreational noise. Cad Saude Publica 2009;25(12):2553-61. PMID 20191147
86: Matz G. Aminoglycoside cochlear ototoxicity. Otolaryngol Clin North Am 1993;26:705-12. PMID 8233484
87: McGill T. Carcinomatous encephalomyelitis with auditory and vestibular manifestations. Ann Otol Rhinol Laryngol 1976;85(1 Pt 1):120-6. PMID 176918
88: McIntyre KM, Favre NM, Kuo CC, Carr MM. Systematic review of sensorineural hearing loss associated with COVID-19 infection. Cureus 2021;13(11):e19757. PMID 34938632
89: Melo RS, Lemos A, Raposo MCF, Monteiro MG, Lambertz D, Ferraz KM. Repercussions of the degrees of hearing loss and vestibular dysfunction on the static balance of children with sensorineural hearing loss. Phys Ther 2021;101(10):pzab177. PMID 34270771
90: Megha, Maruthy S. Auditory and cognitive attributes of hearing aid acclimatization in individuals with sensorineural hearing loss. Am J Audiol 2019;28(2S):460-70. PMID 31461327
91: Miles WR. Carl Emil Seashore: 866-1949. A biographical memoir. Washington DC: Natonal Academy of Sciences, 1956.
92: Miliaras G, Bostantjopoulou S, Argyropoulou M, Kyritsis A, Polyzoidis K. Superficial siderosis of the CNS: report of three cases and review of the literature. Clin Neurol Neurosurg 2006;108:499-502. PMID 16720225
93: Mohammed SH, Shab-Bidar S, Abuzerr S, Habtewold TD, Alizadeh S, Djafarian K. Association of anemia with sensorineural hearing loss: a systematic review and meta-analysis. BMC Res Notes 2019;12(1):283. PMID 31122277
94: Morton NE. The mutational load due to detrimental genes in man. Am J Hum Genet 1960;12:348-64. PMID 14424476
95: Morton NE. Genetic epidemiology of hearing impairment. Ann NY Acad Sci 1991;630:16-31. PMID 1952587
96: Morton CC, Nance WE. Newborn hearing screening--a silent revolution. N Engl J Med 2006;354:2151-64. PMID 16707752
97: Moyer VA. Screening for hearing loss in older adults: US Preventive Services Task Force recommendation statement. Ann Intern Med 2012;157(9):655-61. PMID 22893115
98: Mulrow CD, Aguilar C, Endicott JE, et al. Quality-of-life changes and hearing impairment. A randomized trial. Ann Intern Med. 1990a;113(3):188-94. PMID 2197909
99: Mulrow CD, Aguilar C, Endicott JE, et al. Association between hearing impairment and the quality of life of elderly individuals. J Am Geriatr Soc. 1990b;38(1):45-50. PMID 2295767
100: O'Brien I, Ackermann BJ, Driscoll T. Hearing and hearing conservation practices among Australia's professional orchestral musicians. Noise Health. 2014;16(70):189-95. PMID 24953885
101: Omichi R, Kariya S, Maeda Y, Nishizaki K. Cochlear implantation is a therapeutic option for superficial siderosis patients with sensorineural hearing loss. J Laryngol Otol 2016;130(4):408-11. PMID 26857965
102: Osguthorpe JD, Klein AJ. Occupational hearing conservation. Otolaryngol Clin North Am 1991;24:403-14. PMID 1857619
103: Paakkonen R, Lehtomaki K. Protection efficiency of hearing protectors against military noise from handheld weapons and vehicles. Noise Health 2005;7(26):11-20. PMID 16053601
104: Pandya A, Arnos KS, Xia XJ, et al. Frequency and distribution of GJB2 (connexin 26) and GJB6 (connexin 30) mutations in a large North American repository of deaf probands. Genet Med 2003;5(4):295-303. PMID 12865758
105: Pera A, Dossena S, Rodighiero S, et al. Functional assessment of allelic variants in the SLC26A4 gene involved in Pendred syndrome and nonsyndromic EVA. Proc Natl Acad Sci U S A 2008;105(47):18608-13. PMID 19017801
106: Pirila T. Left-right asymmetry in the human response to experimental noise exposure. Acta Otolaryngol 1991;111:861-6. PMID 1759571
107: Pirila T, Jounio-Ervasti K, Sorri M. Left-right asymmetries in hearing threshold levels in three age groups of a random population. Audiology 1992;31:150-61. PMID 1642566
108: Politzer A. History of Otology. Translated by: Mistein S, Portnoff C, Coleman A. Volume 1. Phoenix, AZ: Columella Press, 1981.
109: Pollak A, Lechowicz U, Murcia Pieńkowski VA, et al. Whole exome sequencing identifies TRIOBP pathogenic variants as a cause of post-lingual bilateral moderate-to-severe sensorineural hearing loss. BMC Med Genet 2017;18(1):142. PMID 29197352
110: Pourova R, Janousek P, Jurovcík M, et al. Spectrum and frequency of SLC26A4 mutations among Czech patients with early hearing loss with and without enlarged vestibular aqueduct (EVA). Ann Hum Genet 2010;74(4):299-307. PMID 20597900
111: Rashaad Hansia M, Dickinson D. Hearing protection device usage at a South African gold mine. Occup Med (Lond) 2010;60(1):72-4. PMID 19666963
112: Raymond M, Walker E, Dave I, Dedhia K. Genetic testing for congenital non-syndromic sensorineural hearing loss. Int J Pediatr Otorhinolaryngol 2019;124:68-75. PMID 31163360
113: Renna R, Plantone D, Batocchi AP. Teaching NeuroImages: a case of hearing loss in a paraneoplastic syndrome associated with anti-Hu antibody. Neurology 2012;79(15):e134. PMID 23045521
114: Ruyschius F. Responsio, ad Virum Expertissimum Dr. Johannem Henricum Graetz. In: Epistolam ejus Anatomicam, Problematicam. De Structura Nasi Cartilaginea, vasis sanguiferis Arteriosis Membranae & Cavitatis tympani & ossiculorum auditus, horumque periostio. Epistola anatomica, problematica octava. Amstelaedami [Amsterdam]: Jansonio-Waesbergios, 1744.
115: Saliba I, Martineau G, Chagnon M. Asymmetric hearing loss: rule 3,000 for screening vestibular schwannoma. Otol Neurotol 2009;30:515-21. PMID 19395982
116: Samocha-Bonet D, Wu B, Ryugo DK. Diabetes mellitus and hearing loss: a review. Ageing Res Rev 2021;71:101423. PMID 34384902
117: Sanyelbhaa H, Kabel A, Abo El-Naga HAE, Sanyelbhaa A, Salem H. The risk ratio for development of hereditary sensorineural hearing loss in consanguineous marriage offspring. Int J Pediatr Otorhinolaryngol 2017;101:7-10. PMID 28964313
118: Seashore CE. An audiometer: Studies in Psychology 2. Iowa City: University of Iowa Press, 1899:158-63.
119: Shah J, Pham GN, Zhang J, et al. Evaluating diagnostic yield of computed tomography (CT) and magnetic resonance imaging (MRI) in pediatric unilateral sensorineural hearing loss. Int J Pediatr Otorhinolaryngol 2018;115:41-4. PMID 30368390
120: Sharma RK, Chern A, Begasse de Dhaem O, Golub JS, Lalwani AK. Chronic obstructive pulmonary disease is a risk factor for sensorineural hearing loss: A US population study. Otol Neurotol 2021;42(10):1467-75. PMID 34387615
121: Shen Y, Hu H, Fan C, et al. Sensorineural hearing loss may lead to dementia-related pathological changes in hippocampal neurons. Neurobiol Dis 2021;156:105408. PMID 34082124
122: Simpson BD, Bolia RS, McKinley RL, Brungart DS. The impact of hearing protection on sound localization and orienting behavior. Hum Factors 2005;47(1):188-98. PMID 15960096
123: Song MH, Shin JW, Park HJ, et al. Intrafamilial phenotypic variability in families with biallelic SLC26A4 mutations. Laryngoscope 2014;124(5):E194-202. PMID 24338212
124: Sprinzl GM, Riechelmann H. Current trends in treating hearing loss in elderly people: a review of the technology and treatment options - a mini-review. Gerontology 2010;56:351-8. PMID 20090297
125: Starck J, Toppila E, Pyykko I. Impulse noise and risk criteria. Noise Health 2003;5(20):63-73. PMID 14558894
126: Stein LM, Thienhaus OJ. Hearing impairment and psychosis. Int Psychogeriatr 1993;5(1):49-56. PMID 8499573
127: Stevens I, Petersen D, Grodd W, Poremba M, Dichgans J. Superficial siderosis of the central nervous system: a 37-year follow-up of a case and review of the literature. Eur Arch Psychiatry Clin Neurosci 1991;241:57-60. PMID 1832307
128: Stoddard GD. Carl Emil Seashore: 1866-1949. Am J Psychol 1950;63(3):456-62. PMID 15432786
129: Strum D, Kapoor E, Shim T, Kim S, Sabetrasekh P, Monfared A. Prevalence of sensorineural hearing loss in pediatric patients with sickle cell disease: a meta-analysis. Laryngoscope 2021;131(5):1147-56. PMID 33091179
130: Sulaiman AH, Seluakumaran K, Husain R. Hearing risk associated with the usage of personal listening devices among urban high school students in Malaysia. Public Health 2013;127(8):710-5. PMID 23474376
131: Sutton SS, Magagnoli J, Cummings TH, Hardin JW. Calcium channel blockers and the risk of sensorineural hearing loss. Otol Neurotol 2022;43(2):e140-7. PMID 34855682
132: Taljaard DS, Leishman NF, Eikelboom RH. Personal listening devices and the prevention of noise induced hearing loss in children: the Cheers for Ears Pilot Program. Noise Health 2013;15(65):261-8. PMID 23771425
133: Tambs K, Hoffman HJ, Borchgrevink HM, Holmen J, Samuelsen SO. Hearing loss induced by noise, ear infections, and head injuries: results from the Nord-Trondelag Hearing Loss Study. Int J Audiol 2003;42(2):89-105. PMID 12641392
134: Thorne PR, Ameratunga SN, Stewart J, et al. Epidemiology of noise-induced hearing loss in New Zealand. N Z Med J 2008;121(1280):33-44. PMID 18791626
135: Toivonen M, Pääkkönen R, Savolainen S, Lehtomäki K. Noise attenuation and proper insertion of earplugs into ear canals. Ann Occup Hyg 2002;46(6):527-30. PMID 12176767
136: Triggs E, Charles B. Pharmacokinetics and therapeutic drug monitoring of gentamicin in the elderly. Clin Pharmacokinet 1999;37:331-41. PMID 10554048
137: Uehara N, Fujita T, Yamashita D, et al. Genetic background in late-onset sensorineural hearing loss patients. J Hum Genet 2022;67(4):223-230. PMID 34824372
138: Urben SL, Benninger MS, Gibbens ND. Asymmetric sensorineural hearing loss in a community-based population. Otolaryngol Head Neck Surg 1999;120:809-14. PMID 10352431
139: Usami S, Abe S, Weston MD, Shinkawa H, Van Camp G, Kimberling WJ. Non-syndromic hearing loss associated with enlarged vestibular aqueduct is caused by PDS mutations. Hum Genet 1999;104:188-92. PMID 10190331
140: van Beeck Calkoen EA, Engel MSD, van de Kamp JM, et al. The etiological evaluation of sensorineural hearing loss in children. Eur J Pediatr 2019;178(8):1195-205. PMID 31152317
141: van Beeck Calkoen EA, Merkus P, Goverts ST, et al. Evaluation of the outcome of CT and MR imaging in pediatric patients with bilateral sensorineural hearing loss. Int J Pediatr Otorhinolaryngol 2018;108:180-5. PMID 29605351
142: Verbeek JH, Kateman E, Morata TC, Dreschler WA, Mischke C. Interventions to prevent occupational noise induced hearing loss. Cochrane Database Syst Rev 2012;10:CD006396. PMID 23076923
143: Verjan-Carrillo EJ, Murillo-Zamora E, Ceja-Espíritu G, Guzmán-Esquivel J, Mendoza-Cano O. Factors associated with increased odds of sensorineural hearing loss in infants exposed to the Zika virus during pregnancy. J Infect Dev Ctries 2021;15(4):590-4. PMID 33956662
144: Vernino S, Lennon VA. Autoantibody profiles and neurological correlations of thymoma. Clin Cancer Res 2004;10(21):7270-5. PMID 15534101
145: Vesalii A. De humani corporis fabrica. Basel: Oporinus, 1543.
146: Vesalii A. De humani corporis fabrica. Basel: Oporinus, 1555:43.
147: Viljanen A, Kaprio J, Pyykkö I, Sorri M, et al. Hearing as a predictor of falls and postural balance in older female twins. J Gerontol A Biol Sci Med Sci 2009;64A:312-7. PMID 19182227
148: Vogel DA, McCarthy PA, Bratt GW, Brewer C. The clinical audiogram: its history and current use. Communicative Disorders Review 2007;1(2):81-94.**
149: Vollrath MA, Kwan KY, Corey DP. The micromachinery of mechanotransduction in hair cells. Annu Rev Neurosci 2007;30:339-65. PMID 17428178
150: Wallner LJ. The otologic effects of streptomycin therapy. Ann Otol Rhinol Laryngol 1949;58:111-6. PMID 18137816
151: Wei Q, Wang S, Yao J, et al. Genetic mutations of GJB2 and mitochondrial 12S rRNA in nonsyndromic hearing loss in Jiangsu Province of China. J Transl Med 2013;11:163. PMID 23826813
152: Willeit J, Aichner F, Fleber S, et al. Superficial siderosis of the central nervous system: report of 3 cases and review of the literature. J Neurol Sci 1992;111:20-5. PMID 1402994
153: Willis T. De anima brutorum quae hominis vitalis ac sensitiva est: exercitationes duae. Prior physiologica ejusdem naturam, partes, potentias & affectiones tradit. Altera pathologica morbos qui ipsam, & sedem ejus primariam, nempe cerebrum & nervosum genus afficiunt, explicat, eorumque therapeias instituit. Oxonii [Oxford]: E Theatro Sheldoniano, Impensis Ric. Davis, 1672.
154: Working Group on Communication Aids for the Hearing-Impaired. Speech-perception aids for hearing-impaired people: current status and needed research. J Acoust Soc Am 1991;90:637-83.** PMID 1939883
155: World Health Organization. WHO Report of the Informal Working Group On Prevention Of Deafness And Hearing Impairment Programme Planning. Geneva: World Health Organization, 1991.
156: World Health Organization. WHO global estimates on prevalence of hearing loss. Mortality and Burden of Diseases and Prevention of Blindness and Deafness. Geneva: World Health Organization, 2012.
157: Xia W, Yan H, Zhang Y, et al. Congenital human cytomegalovirus infection inducing sensorineural hearing loss. Front Microbiol 2021;12:649690. PMID 33936007
158: Yang JJ, Tsai CC, Hsu HM, Shiao JY, Su CC, Li SY. Hearing loss associated with enlarged vestibular aqueduct and Mondini dysplasia is caused by splice-site mutation in the PDS gene. Hear Res 2005;199:22-30. PMID 15574297
159: Yang T, Vidarsson H, Rodrigo-Blomqvist S, Rosengren SS, Enerback S, Smith RJ. Transcriptional control of SLC26A4 is involved in Pendred syndrome and nonsyndromic enlargement of vestibular aqueduct (DFNB4). Am J Hum Genet 2007;80(6):1055-63. PMID 17503324
160: Yee J, Han HW, Gwak HS. Proton pump inhibitor use and hearing loss in patients with type 2 diabetes: Evidence from a hospital-based case-control study and a population-based cohort study. Br J Clin Pharmacol 2022;88(6):2738-46. PMID 34970788
161: Zeitler DM, Dunn C, Schwartz SR, et al. Health-related quality of life in children with unilateral sensorineural hearing loss following cochlear implantation. Otolaryngol Head Neck Surg 2023;168(6):1511-20. PMID 36934432
162: Zhang J, Sawaf T, Anne S, et al. Imaging in pediatric bilateral sensorineural hearing loss: Diagnostic yield with computed tomography versus magnetic resonance imaging. Int J Pediatr Otorhinolaryngol 2021;147:110778. PMID 34049106
163: Zimbardo PG, Andersen SM, Kabat LG. Induced hearing deficit generates experimental paranoia. Science 1981;212(4502):1529-31. PMID 7233242

This is an article preview.
Start a Free Account
to access the full version.

Nearly 3,000 illustrations, including video clips of neurologic disorders.
Every article is reviewed by our esteemed Editorial Board for accuracy and currency.
Full spectrum of neurology in 1,200 comprehensive articles.
Listen to MedLink on the go with Audio versions of each article.

Questions or Comment?

MedLink®, LLC

3525 Del Mar Heights Rd, Ste 304
San Diego, CA 92130-2122

Toll Free (U.S. + Canada): 800-452-2400

US Number: +1-619-640-4660

Support: service@medlink.com

Editor: editor@medlink.com

ISSN: 2831-9125

Sensorineural hearing loss

Differential Diagnosis

otic capsule dysplasia syndromes
intrauterine infections
rubella
cytomegalovirus
herpes simplex
- syphilis
- maternal drug or alcohol abuse
- infectious and postinfectious conditions
- suppurative labyrinthitis
- meningitis
- measles
- mumps
- herpes zoster oticus
- ototoxic drugs
- autoimmune factors
- Susac syndrome
- traumatic head injury
- inner ear concussion
- perilymph fistula
- shear injury of the eighth nerve
- temporal bone fracture
- Meniere disease
- noise-induced cochlear injury
- vascular injury
- labyrinthine infarction
- superficial siderosis
- neoplastic and paraneoplastic conditions
- cerebellopontine angle tumors
- carcinomatous meningitis
- paraneoplastic subacute hearing loss
- cochleovestibulopathy
- nutritional disorders
- presbycusis
- small cell lung cancer
- thymoma
- neuroblastoma
- B-cell follicular lymphoma
- noise exposure
- vascular occlusive disease

Also Relevant

Autoimmune sensorineural hearing loss
Central deafness
Hearing loss in infants and children
Meniere syndrome
Noise-induced hearing loss
- Otic capsule dysplasia
- Presbycusis
- Pure-tone audiometry
- Subjective tinnitus
- Sudden deafness

Sensorineural hearing loss …

Sensorineural hearing loss

Introduction

Overview

Key points

Historical note and terminology

Clinical manifestations

Presentation and course

Table 1. World Health Organization Grades of Hearing Impairment (assessed in better ear)

Table 2. Degree of Hearing Loss

Prognosis and complications

Biological basis

Etiology and pathogenesis

Epidemiology

Prevention

Differential diagnosis

Associated or underlying disorders

Diagnostic workup

Management

Media

References

Contributors

Author

Patient Profile

ICD & OMIM codes

This is an article preview.
Start a Free Account
to access the full version.

Questions or Comment?

Also in This Category

Recurrent painful ophthalmoplegic neuropathy

Congenital lymphocytic choriomeningitis virus infection

Hearing loss in infants and children

Urinary dysfunction in neurologic disorders

NF2-related schwannomatosis

Dysphagia

Neurovascular injuries

Botulinum toxin treatment of neurologic disorders

Sensorineural hearing loss

Introduction

Overview

Key points

Historical note and terminology

Clinical manifestations

Presentation and course

Table 1. World Health Organization Grades of Hearing Impairment (assessed in better ear)

Table 2. Degree of Hearing Loss

Prognosis and complications

Biological basis

Etiology and pathogenesis

Epidemiology

Prevention

Differential diagnosis

Associated or underlying disorders

Diagnostic workup

Management

Media

References

Contributors

Author

Patient Profile

ICD & OMIM codes

This is an article preview. Start a Free Account to access the full version.

Questions or Comment?

Also in This Category

Recurrent painful ophthalmoplegic neuropathy

Congenital lymphocytic choriomeningitis virus infection

Hearing loss in infants and children

Urinary dysfunction in neurologic disorders

NF2-related schwannomatosis

Dysphagia

Neurovascular injuries

Botulinum toxin treatment of neurologic disorders

This is an article preview.
Start a Free Account
to access the full version.