Hearing Impairment 

Updated: Oct 07, 2021
Author: Rahul K Shah, MD, FACS, FAAP; Chief Editor: Ravindhra G Elluru, MD, PhD 

Overview

Practice Essentials

Hearing loss is more prevalent than diabetes mellitus, myelomeningocele, all pediatric cancers, and numerous other medical conditions.[1] However, medical professionals typically learn little about hearing impairment, about how to advise parents of children who are deaf or hard of hearing, or about the special considerations needed in the care of children with hearing loss.

In the past two decades, recommendations for universal neonatal hearing screening resulted in numerous articles regarding the tests, the efficacy of testing, the role of the audiologist in amplification, and the importance of early intervention programs.[2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]

The role of the primary care physician cannot be overemphasized. In many instances, the otolaryngologist develops a long-term relationship with patients and their families, caring for the patients through their spectrum of development, especially if the otolaryngologist is part of a cochlear implant program. In addition to the surgeon, most cochlear implant teams include audiologists, speech therapists, and, sometimes, social workers. These teams can be very helpful to deaf children, their families, and their primary care physicians.

Pediatricians play a crucial role in providing referrals to audiologists, otolaryngologists, and special programs. To do so, they must understand the nature of hearing loss and the equipment that can improve auditory reception, the linguistic and social development of children who have hearing impairment, and the educational and linguistic options available to children who are deaf or hard of hearing.

The goals must always be to integrate the child into the family and into society and to enable the growth and development of a healthy, confident child who is deaf or hard of hearing. To meet these goals, clinicians should use whichever communication strategy and equipment that is best suited for the individual child and his or her family.

Anatomy

Sound waves arrive to the auricle and are channeled through the external auditory canal to the tympanic membrane. When they strike the tympanic membrane, the waves cause it to vibrate, setting off a chain of vibrations along the ossicles (malleus, incus, and stapes) to the membrane of the oval window at the entrance to the cochlea. This process amplifies environmental sound by approximately 20-fold.

The cochlea is the end organ of hearing and is shaped like a snail shell with two and one half turns. (See Inner Ear Anatomy.) Inside, two membranes longitudinally divide the cochlea into three sections: the scala tympani, the scala vestibuli, and the scala media. All three are filled with fluids of differing ion concentrations (similar to intracellular and extracellular constituents).

Along one of the membranes in the scala media, or cochlear duct, lie the internal and external hair cells. Movement of the stapes on the oval window creates a wave or vibration in the perilymph fluid of the cochlea. This fluid movement, which opens ion channels in the hair cells, displaces the hair cells, triggering an action potential and causing a nerve in the cochlea to fire to the brain.

Thousands of nerves, representing more than 20,000 frequencies, are located along the length of the cochlea; these nerves account for the hearing range. The microscopic nerves culminate in the cochlear portion of the eighth cranial nerve. The location of the vibration in the cochlea correlates with the frequency of the original pitch. Low-frequency sounds are near the apex, and high-frequency sounds are near the base.

Pathophysiology

Types of hearing loss

Conductive hearing loss (CHL) results from anything that decreases the transmission of sound from the outside world to the cochlea. Causes include abnormal formation of the auricle or helix, impaction of cerumen in the ear canal, effusions in the middle ear, or dysfunction or fixation of the ossicular chain. Otosclerosis is one of the most common examples.

An important cause of CHL is a cholesteatoma, a locally destructive but benign growth. Other neoplasms can affect the middle ear as well. Examples include glomus tympanicum or glomus jugulare, schwannomas of the facial nerve, and hemangiomas. Dehiscence of the roof of the middle ear (tegmen mastoideum), such as is caused by an encephalocele, can result in CHL. In CHL, sounds perceived by the brain are diminished but are generally not distorted.

Sensorineural hearing loss (SNHL) may result from disruptions in transmission after the cochlea. These disruptions may be a result of hair cell destruction in the cochlea or damage to the eighth cranial nerve. Sounds perceived by the brain are both diminished and distorted. The degree of distortion is independent of the degree of hearing loss; for example, it is possible to have only mild hearing loss yet have very poor speech discrimination.

Auditory dyssynchrony should be considered in the setting of no auditory brainstem response (ABR), no middle-ear muscle response, normal otoacoustic emissions, or normal cochlear microphonics.

Mixed hearing loss has components of both CHL and SNHL.

Categories of hearing loss

Regardless of the type, the American National Standards Institute defines hearing loss in terms of decibels (dB) lost, as follows:

  • Slight hearing loss - 16-25 dB
  • Mild hearing loss - 26-40 dB
  • Moderate hearing loss - 41-55 dB
  • Severe hearing loss - 71-90 dB
  • Profound - More than 90 dB

Etiology

In 2014, the American College of Medical Genetics and Genomics published a guideline that provided information about the frequency, causes, and presentations of hearing loss and suggested approaches to clinical evaluation aimed at identifying an etiologic diagnosis of hearing loss (see Guidelines).[14]

Genetic causes

Most sources cite genetic causes as accounting for at least 50% of hearing loss.[1, 15, 16, 17] These can be divided into syndromic and nonsyndromic types. As with all genetic syndromes, genetic causes of hearing loss may be autosomal dominant (AD), autosomal recessive (AR), X-linked, mitochondrial, or sporadic.

Nonsyndromic deafness accounts for slightly more than two thirds of all cases of genetic deafness. It probably accounts for most cases classified as unknown. Children with nonsyndromic deafness are deaf or hard of hearing; however, they have no other physical abnormalities, no particular risk to other organ systems, and no increased risk of mental deficiency. Some children have a history of deafness in a close or distant family member. Others have new mutations or an AR gene with no known proband. The histories of subsequent siblings and progeny may help to distinguish a genetic cause from developmental arrest or a prenatal insult.

Exciting developments in genetic mapping have revealed approximately two dozen abnormal genes that lead to deafness. These genes have been classified according to their mode of inheritance: ADs (DFNA1 through DFNA48), ARs (DFNB1 through DFNB67), X-linked recessives (DFN1 through DFN8), or mitochondrial (at least five loci identified, including 12Sr RNA and tRNA-Ser UCN).

Mutations in these genes result in a functional or structural defect (eg, collagen in the basilar membrane; a structural defect in a membrane-gating protein, such as connexin-26).[18] In some of these, one or more specific mutations in the DNA sequence have been identified. One example is DFNA44, for which the problem is on gene CCDC50, which codes for Ymer, a cytoplasmic protein that inhibits the downregulation of the epidermal growth factor receptor, affecting the normal development of the structural organization of the pillar cells of the inner ear.[19, 20] Several of the genes exhibit variable penetrance, and so the presence of the gene does not correlate directly with the degree of hearing loss.

Syndromic deafness accounts for the remaining cases of genetic deafness, with more than 300 syndromes described.[2] Some syndromes have a particular inheritance pattern (eg, AD for Waardenburg syndrome and Gernet syndrome, AR for Jervell Lange-Nielson syndrome and Winter syndrome, X-linked for Alport syndrome and Rosenberg syndrome). Others are sporadic (eg, cat-eye syndrome, Turner syndrome, Klinefelter syndrome).

Physical findings usually help indicate the presence of a particular syndrome; however, children with some syndromes do not develop the associated physical findings until late in childhood. Other children present early in life with either deafness or the sequelae of a biochemical or metabolic derangement.

As noted above, syndromes may affect any single organ or several organ systems. Just as the genetics of nonsyndromic deafness have advanced, more is known about the genetics of syndromes associated with deafness. For example, Waardenburg syndrome type IV is caused by an abnormality of endothelin 3 (EDN3), which results in abnormalities of ligand molecules affecting striatal intermediate, GI, and pigment cells.[21]

Syndromic associations

A small sample of syndromes associated with deafness is summarized in Table 1 below. A few may be familiar, though many are not; most are fairly uncommon.

Table 1. Selected Syndromes Associated With Deafness (Open Table in a new window)

Organ or System

Syndrome

Inheritance Pattern

Type of Hearing Loss

Obvious Physical Abnormalities

External ear

DiGeorge sequelae

Sporadic

CHL

Yes

Branchio-oto-facial syndrome

AD

CHL

Yes

Townes-Brocks syndrome

AD

SNHL

Yes

Miller syndrome

AR

CHL

Yes

Bixler syndrome

AR

CHL

Yes

Cardiac

Coloboma, heart disease, atresia choanae, retarded growth, and ear anomalies (CHARGE) syndrome

AD, AR, X linked, sporadic

SNHL, mixed

Yes

Jervell Lange-Nielson syndrome

AR

SNHL

No

Limb-oto-cardiac syndrome

AR

CHL

Yes

Renal

Alport syndrome

AD, AR, X linked

SNHL

Yes or no

Branchio-oto-renal syndrome

AD

SNHL, CHL

Yes

Kearns-Sayre syndrome

Sporadic

SNHL

Yes

Epstein syndrome

AD

SNHL

No

Barakat syndrome

AR

SNHL

No

Mental (retardation)

Noonan syndrome

Sporadic

SNHL

Yes

Killian/Teschler-Nicola syndrome

Sporadic

SNHL

Yes

Cockayne syndrome, type I

AR

SNHL

Yes

Gustavson syndrome

X linked

SNHL

Yes

Dermatologic

Waardenburg syndrome

AD

SNHL

Yes

Lentigines, ECG, ocular, pulmonary, abnormal, retardation, and deafness (LEOPARD) syndrome

AD

SNHL

Yes

Senter syndrome

AR

SNHL

Yes

Black locks with albinism and deafness (BADS) syndrome

AR

SNHL

Yes

Davenport syndrome

AR

SNHL

Yes

Endocrine and/or metabolic

Pendred syndrome

AR

SNHL

Yes or no

Johanson-Blizzard syndrome

AR

SNHL

Yes

Refetoff syndrome

AR

SNHL

Yes

Wolfram syndrome

AR

SNHL

Yes or no

Kallmann syndrome

AD, AR, X linked

SNHL, mixed

Yes or no

Facial

Goldenhar syndrome

AD, AR

CHL, SNHL

Yes

Frontometaphyseal dysplasia

X linked

Mixed

Yes

Escher-Hirt syndrome

AD

CHL

Yes

Levy-Hollister syndrome

AD

SNHL

Yes

Ophthalmologic

Usher syndrome

AR

SNHL

Yes or no

Marshall syndrome

AD

SNHL

Yes

Alström syndrome

AR

SNHL

Yes

Harboyan syndrome

AR

SNHL

Yes or no

Fraser syndrome

AR

CHL

Yes

Jensen syndrome

X linked

SNHL

No

Orthopedic

Klippel-Feil sequelae

Sporadic

CHL, SNHL

Yes

Stickler syndrome

AD

CHL, SNHL, mixed

Yes

Craniometaphyseal dysplasia

AD, AR

CHL, mixed

Yes

Oto-spondylo-megaepiphyseal dysplasia (OSMED) syndrome

AR

SNHL

Yes

AD = autosomal dominant; AR = autosomal recessive; CHL = conductive hearing loss; SNHL = sensorineural hearing loss.

For many of these syndromes, good data about actual prevalences are difficult to find. The first few syndromes listed for each organ or system are the ones most commonly known. They may be most widely recognized because their associated findings or illnesses may result in high morbidity or mortality, because the physical stigmata are classic and therefore make the syndrome easily identifiable, or because they are overrepresented in test questions on pediatric examinations.

Antenatal causes

Antenatal causes lead to 5-10% of hearing losses. Congenital infections (eg, cytomegaloviral [CMV] infections, herpes, rubella, syphilis, toxoplasmosis, varicella) can result in SNHL.[22] Fetal exposure to teratogens (eg, methyl mercury, retinoic acid, thalidomide, trimethadione) may also result in SNHL. Most of these perinatal insults result in physical abnormalities, which should prompt the clinician to recognize the diagnosis and perform a confirmatory evaluation.

However, the physical findings sometimes are subtle or are not apparent until the child ages (eg, Hutchinson molars). In these cases, it may be the identification of hearing loss that leads to the evaluation leading to the diagnosis, or even the later appearance of developmental delays. Even if children with a known antenatal exposure pass the neonatal screen, careful follow-up of their hearing is necessary.

Perinatal causes

Perinatal causes are responsible for 5-15% of hearing losses. A history of prematurity, low birth weight, anoxia or low Apgar scores (see the Apgar Score calculator), hyperbilirubinemia, or sepsis should prompt an evaluation of hearing because these conditions may also result in SNHL.

Postnatal causes

About 10-20% of hearing loses are due to postnatal causes. Childhood infections, such as meningitis or mumps, may result in SNHL. Treatment with ototoxic medications, such as aminoglycosides or furosemide, also can lead to SNHL. Otitis media or major head injury may cause SNHL or CHL. A study by Schieffer et al found that iron deficiency anemia was associated with an increased likelihood of SNHL in children and adolescents.[23]

Unknown causes

In about 20-30% of deaf children, no certain cause can be identified. Their hearing losses likely result from a maldevelopment of the ear or the neurologic system. Such an event may have been a developmental accident or the result of an undiagnosed infection or exposure to a teratogenic agent. However, many are likely due to an undiagnosed genetic defect that may represent a new mutation or a genetic recessive trait. Psychogenic hearing loss is also known to occur.[24]

Epidemiology

United States and international statistics

Hearing loss occurs in approximately 5-10 per 1000 children in the United States. Roughly 1-3 in 1000 children are born with profound hearing loss, and 3-5 in 1000 are born with mild-to-moderate hearing loss that may affect language acquisition unless hearing, language, or both are aided.[6] The prevalence of hearing loss requiring intervention among graduates from neonatal intensive care units (NICUs) is 1-4%. Acquired hearing loss in children may add another 10-20% to these numbers.[15]

The prevalence of hearing loss in adolescents aged 12-19 years appears to be increasing in the United States.[25]  A 2010 study found that this increase in prevalence was approximately one third greater from 2005 to 2006 than from 1988 to 1994. Interestingly, significant hearing loss (≥25 dB) was particularly increased, to the point where approximately 1 in 20 adolescents has this type of hearing loss. Noise-induced hearing loss contributes substantially to the increased incidence of hearing loss in adolescents.

Data from the United States Census show that almost 3% of the population in the workforce reports having some hearing loss, including CHL, SNHL, or mixed loss.

Worldwide, SNHL occurs in 9-27 per 1000 children.

Age- and sex-related demographics

Most hearing loss in children is congenital or acquired perinatally.[16] However, hearing loss may occur at any age. Approximately 10-20% of all cases of deafness are acquired postnatally, though some genetic causes of deafness result in hearing loss that begins during childhood or adolescence or is slowly progressive and therefore diagnosed in childhood or adolescence.

No sex predilection is known. Some hereditary causes of deafness or acquired deafness may occur more frequently in one sex than in the other. However, the overall prevalence of deafness is equal in male and female individuals.

Patient Education

Assisting and educating parents

It must be remembered that although most deaf children are otherwise healthy, a parent's response to having a child with hearing impairment is generally the same as that of a parent whose child has a physical disability or chronic medical condition. Some deaf children have both hearing loss and other disabilities or medical conditions. Help parents to identify available resources (such as those listed at the end of this section), or refer them to a social worker or counselor who can provide specialized assistance.

In some states, social workers assigned to families with deaf or hard-of-hearing children are required to have a background in disabilities or hearing loss. Many states assign the next social worker available, in which case the worker has no more ability to determine the best form of communication, the best school environment, or the best resources than the primary care provider does.

The information available on the Internet may be selected strictly on the basis of geographic location, the number of "hits" in a search engine (making the site appear at the top of the list), alphabetical sorting, or the manner in which the resource is structured. If possible, the patient’s family should be directed towards people with expertise in the field and towards sources without obvious bias.

Parents must understand that deafness is not an all-or-nothing categorization and that being hard of hearing is not defined by the hearing loss being in the middle ranges (eg, 30-60 dB). Children with CHL are likely to develop good use of speech with appropriate amplification. Children with SNHL are more variable.

In SNHL, the nature of the sound may be distorted, which means that amplification of the deficit may not improve the child's language comprehension in any meaningful way. A helpful analogy is that of a radio signal that is mostly static; it remains unintelligible no matter how loud it is. Therefore, children with moderate SNHL (41-55 dB) may have minimal benefit to improving language comprehension, although they may have good benefit from improved ability to hear environmental cues.

Communication is the most important loss in deafness. Communication is necessary for socialization and integration into the family and into society. All interventions must have the goal of optimizing the child's ability to successfully communicate and interact socially.

Lip-reading (oralism) and sign language

Considerable debate continues regarding the choice of lip-reading (oralism) versus sign language. Lip-reading may be taught alone or supplemented with cued speech. In the United States, sign language can be in the form of American Sign Language (ASL) or Signed English (SE) with Signing Exact English/Seeing Essential English (SEE, which is sometimes distinguished as Signing Exact English [SEE 1] and Seeing Essential English [SEE 2]). PSE (Pidgin Signed English) is not used educationally, but functionally it combines the use of signs using an English-based grammar, but like any pidgin language uses neither proper English grammar nor ASL grammar.

Parents must be able and willing to accept and then participate in the language that they chose for their child. They should be vigilant and remember that school failures and behavior problems are not inherent to deafness but frequently result from a frustrated child who has no language, no ability to communicate, and no ability to connect with others.

Advantages and disadvantages of lip-reading

The greatest advantage of lip-reading is that parents and society are required to make only minimal adjustments for the deaf individual. Therefore, deaf children must learn to speak for themselves and understand the speech of others.

The disadvantages are numerous. First, formal training can begin only at school age. Therefore, language acquisition is delayed beyond the optimal neurobiologic window for language acquisition, between approximately age 3-5 years (although some evidence indicates it may be as young as 9-18 mo).

Second, almost half of the consonants in English appear similar when spoken (eg, d-t, f-v, g-k, b-p-m). That is, they look identical on the lips but are distinguishable to hearing people when spoken. Other sounds appear the same, such as /ch/, /j/, and /sh/, making "chew," "Jew," and "shoe" indistinguishable from each other (this includes the "soft g" as in "George" and all variations of /sh/, as in "fish," "Charlotte," and "nation." Many vowel sounds appear similar, especially compared with their written equivalent. For example, the sound /oo/ may be written as “to,” “too,” “threw,” “through,” “due,” or “shoe.”

Lip-reading is hard to master and tiring to perform. To appreciate the difficulty, imagine reading this page with no spaces between the words and with only periods as punctuation. Then, imagine the text passing in front of you as if on an electronic billboard, and that every /p/ might be a /b/ or /m/, every /d/ could be a /t/, every /ch/ could be /j/ or /sh/, and so on.

Fourth, lighting, distance, speech impediments, accents, and foreign objects or motion can make lip-reading more difficult (eg, faces silhouetted by light, food, pencils, fingers, mustaches, turning the head).

As a result, typical lip-readers understand only one third of a one-to-one conversation. The best lip-readers understand about two thirds. In general, children with more hearing and better speech discrimination than others are most successful with lip-reading.

Finally, the lip-reader cannot localize a speaker. During a one-to-one conversation between the lip-reader and one other person, there is only the one set of lips to watch. Even a third person makes the conversation difficult because when the speaker’s lips stop moving, it could be a pause, or the other speaker has started speaking. The lip-reader must guess if he or she should continue to look at the speaker’s lips, risking missing the opening words of the second party (those which best set up context—for example, agreement or disagreement with the first speaker). To look at the other person’s lips risks missing the continued comments of the speaker.

In a group setting, the lip-reader may miss several entire comments by the time his or her eyes identify the speaker. Having more hearing is helpful in group situations. Although hearing aids help to localize sound, they also amplify each voice equally, which may decrease the ability to accurately use the sounds that are heard.

Deaf and hard-of-hearing people who use either lip-reading or cued speech must learn to speak for themselves. They have varying success, but many can make themselves understood in most situations.

The challenge is simple. They must learn to create sounds they cannot hear. A simple analogy would be teaching a blind person to paint in watercolors. It would be possible for blind people to make the design by embossing the paper with an image they can feel, and then fill in the areas (like painting by numbers) with colors they cannot truly imagine. Deaf people use surrogates for sound to produce noises they cannot imagine. Traditional “sound surrogates” would be making a feather blow with plosive sounds, or feeling the throat vibrate to understand when the larynx is engaged.

More modern technologies include matching speech patterns on oscilloscopes or similar equipment, or “green light” when the deaf person’s spoken word matches the computer’s. Many hearing people cannot even imitate another regional or foreign accent, and few people speaking a new language ever speak without a residual accent from their native language, despite the fact that they can hear the new language and compare their voice with it. Just as some hearing people go to a specialist to learn to speak with an accent or to ablate their native accent, some deaf people who already have learned to speak will return to speech therapists every few years to maintain their speech quality.

Puberty and growth, changes in their vocal cords due to maturation and use (or misuse), and changes in their mouth and shape of their oropharynx occur throughout their lives, altering their ability to produce speech sounds. Without being able to hear themselves and self-correct, they seek professional help to do so.

Cued speech

Cued speech aids lip-reading because hand shapes are placed near the mouth. These shapes help in discriminating sounds that are difficult to distinguish by observing the lips alone.

Parents must learn how to cue. The technique is similar to shorthand in that as sounds, not letters, are cued. For example, the /sh/ sounds in fish, chard, and nation are all cued in the same way, with a "L" or "gun" hand shape placed by the chin, whereas the /p/, /b/, and /m/, which are identical on the lips, are cued by the chin with one finger, four fingers, or all five fingers with the fingers flat and close together, respectively.

Because cued speech is the language of neither the parents nor society, cued-speech interpreters may be required in situations such as interviews or public events. These interpreters are harder to locate than sign-language or oral interpreters.

Similar to instruction in lip-reading, instruction in cued speech cannot begin at an early age; therefore, language acquisition is delayed.

Systems of manual and visual sign language

In the United States, manual and visual signing systems include SEE and ASL.

SEE is visually encoded English, using or adapting the signs of ASL and imposing exact order of the spoken word on the signs. SEE invents suffixes (dog vs dogs), conjugations (see vs sees, -ing, -ed), and signs (the) that are not necessary in the grammar of ASL. These make the signs and sign order identical to English.

SEE is long and tiresome. However, children who use SEE grow up signing what they learn to read and write, just as hearing children speak and hear what they later read and write. Because it takes too long, most people end up omitting or changing some of the signs, and they use PSE. Therefore, children do not benefit from the English-grammar aspect of SEE as much as they might; they learn neither proper English grammar nor proper ASL grammar.

ASL has a unique grammar. It requires fewer signs than SEE does to complete most thoughts because it incorporates space and time into the motion of signs in a way that spoken language cannot. It is efficient and beautiful to watch. However, the child must grow up being bilingual. The grammar used for ASL must be translated into English in order to write.

An advantage of ASL or SEE is that instruction may begin immediately when hearing loss is diagnosed. In fact, children of parents who are deaf learn to sign as their first language, and they begin to sign babble as early as 6-9 months, when hearing children begin to babble normally. In addition, signs are clearly visible at distances, and signing is the preferred language of the Deaf community.

Research suggests that a strong linguistic background is as important to reading and language development as the actual language itself. Therefore, learning ASL may aid the development of English language skills rather than confuse them. Remember, it was not too long ago that educators told immigrant parents not to confuse their children with their foreign languages and to focus on English. Now it is accepted that children can easily learn several languages simultaneously, and it may enhance their ability to acquire languages later in life.

The biggest disadvantage is that sign language is not the language of the hearing world; therefore, interpreters are necessary. It is usually not the language of the family, and many families are intimidated by having to learn a new language to communicate with their child. In fact, 20% of children who are deaf who sign have no family members who sign, and 40% have only one family member who signs. Parents must be reminded that as long as they are one sign ahead of their child in early childhood, they know all they need to maintain communication and linguistic development. With only a few signs, love and discipline can be clearly expressed.

Total communication with sign language and voice

Total communication allows children with residual hearing to benefit from supplemental auditory information. It may also help students in lip-reading because signs with meaning can be associated with movements of the mouth. (For example, mouth the words "I'm going to bed" to your spouse at bedtime; he or she probably understands because the phrase is short and the context is clear; if you said it at a baseball game, your spouse initially would assume he or she had misunderstood.)

The main disadvantage is that speaking English while signing ASL at the same time is almost impossible. As a result, neither of the grammars is effectively or consistently applied.

School placement and schools for children with hearing impairment

Educational placements largely depend on the choice of language.

Children who are learning to lip-read attend an oral school where lip-reading is taught. A portion of the day is spent in lip-reading instruction, and other subjects cannot truly be learned until adequate language is established. As children age, they can be placed in a regular hearing classroom ("mainstreamed") if their lip-reading and vocal skills are sufficient. Their experience there depends on the teacher's ability to accommodate the needs of the student (eg, by not spending much time facing the blackboard and away from the student). Oral interpreters may also be provided to the student in a mainstream classroom. Many children who are deaf and who have succeeded to this point do well in school with their peers.

The experience for students using Cued Speech is not dissimilar. Once their language skills are established, they may stay in a program that uses Cued Speech, or they may enter a mainstream classroom with a Cued Speech interpreter.

Many children who are entering a school where sign language is used have already learned some signs at home or in early intervention. The classroom may consist of deaf children of deaf adults whose first language is ASL and children with minimal sign language skills. Because sign language is visual, young children who are immersed in a signing setting rapidly acquire the signs for objects, people, and, ultimately, grammar. Shortly thereafter, formal educational programming can begin. The process is analogous to most kindergarten classes, which tend to be more social than academic, and language acquisition occurs in a similar fashion in many bilingual school programs for foreign languages.

The use of ASL or SEE in schools is debated by educators, but it is of relatively little importance early in the child’s education, especially when the goal is to foster the development of language, communication, and social skills.

Another debate is the location of deaf/signing programs, residential or mainstream programs. Placing children who are deaf or hard of hearing with hearing children in the least restrictive environment (mainstreaming) may not be as successful for deaf children as it is for children with other disabilities. Many so-called mainstream classrooms are isolated from those for hearing children, and the children who are deaf are instead grouped with children who have learning disabilities or mental retardation. Even in an integrated classroom, instruction happens through the interpreter.

When children are engaging in nonacademic subjects or when no interpreter is present, communication between deaf students and their classmates is limited. Children who have acquired only minimal sign skills will not understand the interpreter, and they have minimal opportunity to practice their signing with their classmates who do not sign. Children who have more advanced sign language may do much better in a hearing classroom from the academic perspective, but their ability to socialize with other students or participate in extracurricular activities is limited.

In some cities, there are deaf programs at hearing schools. Some of these programs put deaf children of varying ages together with a signing teacher. The educational model is more like independent study, with each child working on their assignments. However, the language of instruction is sign, and they interact with signing classmates. Other programs are able to assemble sufficient numbers of deaf students to have entire classes of deaf students with a signing teacher, but on the campus of a hearing school. Depending on the programs resources, students usually are able to participate in extracurricular activities.

Residential deaf schools are on the decline because of the recent desire to keep deaf children at home with their families. Relatively few independent day schools for the deaf exist: no more than one or two in each state.

At a deaf school, where everyone signs, students can participate in many extracurricular and academic activities, such as debate team, football, and cheerleading. Because most deaf children live in a hearing household that is linguistically isolated to them, a school environment that is completely linguistically accessible to the child promotes self-esteem and social skills. The children are able to use sign language all day and all night. They engage and interact with peers and deaf children of different ages. They can develop leadership skills in a way that they may not be able to living at home. Most deaf adults who attended such residential schools look back on that experience as being the best time of their lives.

Choice of language and school placement

The debates rage on, and all parties can be vehement in their views. No one opinion is right, and little literature of adequate quality strongly supports any particular standpoint. Few well-performed studies exist, and the results of most studies cannot be generalized to apply to the majority of children who are deaf and hard of hearing. Therefore, the best approach is to make decisions based on the individual, to meet the needs of a particular child, including the parents’ beliefs and resources, and programs available to them. The goal of pediatricians should be continual monitoring of the child's progress. If the child is not succeeding in one environment or with one choice, suggest a trial in a different one.

Devices to aid children with hearing impairment

Young children need only hearing aids. As they grow, the family should be encouraged to obtain devices such as strobe lights connected to doorbells, timers, alarm clocks, and fire alarms. Telecommunication Devices for the Deaf (TDDs) and teletypewriters (TTYs) are machines than enable deaf people to use the phone. Computers with modems or video/webcam, cell phones with text messaging or instant messaging, and other hand-held devices all permit children to communicate using modern technologies.

These and other aids help children with hearing impairment to develop a sense of independence and accomplishment, just as hearing children do when they complete tasks such as waking up for school using their own alarm clock or baking a cake for the first time.

Schools should also use FM amplification systems to transmit the teacher's voice to a small headphone speaker the child wear just behind the hearing aid. This system amplifies the teacher's voice over extraneous noise.

All new televisions are equipped with closed captioning, which decodes the captioning of dialogue and action provided with most television shows, videotapes, and DVDs. This not only makes television accessible but also promotes reading skills in deaf and hearing children alike.

Resources

Alexander Graham Bell Association for the Deaf and Hard of Hearing

3417 Volta Place, NW

Washington, DC 20007

Voice: (202) 337-5220

TTY: (202) 337-5221

Fax: 202-337-8314

E-mail: info@agbell.org

American Academy of Audiology

11730 Plaza America Drive, Suite 300,

McLean, VA 22102

Voice: (800) AAA-2336, (703) 790-8466

Fax: (703) 790-8631

E-mail: info@audiology.org

American Deafness and Rehabilitation Association (ADARA)

ADARA National Office

PO Box 480

Myersville, MD 21773

E-mail: ADARAorgn@aol.com

American Hearing Research Foundation

8 South Michigan Avenue, Suite 814

Chicago, IL 60603-4539

Voice: (312) 726-9670

Fax: (312) 726-9695

E-mail: ahrf@american-hearing.org

Gallaudet University

Laurent Clerc National Deaf Education Center

and

National Center for Law and the Deaf

800 Florida Avenue, NE

Washington, DC 20002

Hearing Loss Association of America (HLAA, formerly Self Help for Hard of Hearing People [SHHH])

7910 Woodmont Ave, Suite 1200

Bethesda, MD 20814

Phone: (301) 657-2248

Helen Keller National Center for Deaf-Blind Youths and Adults (HKNC)

141 Middle Neck Road

Sands Point, NY 11050

Voice, TTY: (516) 944-8900

E-mail: hkncinfo@hknc.org

House Ear Institute (HEI)

2100 West Third Street

Los Angeles, CA 90057

Voice: (213) 483-4431

TTD: (213) 483-2642

Fax: (213) 483-8789

E-mail: info@hei.org

National Association of the Deaf (NAD)

8630 Fenton Street, Suite 820

Silver Spring, MD 20910-3819

Voice: (301) 587-1788

TTY: (301) 587-1789

Fax: (301) 587-1791

National Cued Speech Association (NCSA)

5619 McLean Drive

Bethesda, MD 20814-1021

Voice, TTY: (800) 459-3529, (301) 915-8009

National Fraternal Society of the Deaf

1188 South Sixth Street

Springfield, IL 62703

Voice: (217) 789-7429

TTY: (217) 789-7438

Office of Special Education and Rehabilitative Services (OSERS)

US Department of Education

400 Maryland Avenue, SW

Washington, DC 20202-7100

Voice: (202) 245-7468

Parmly Hearing Institute

Loyola University

6525 North Sheridan Road

Chicago, IL 60626

Voice: (773) 508-2710

Fax: (773) 508-2719

E-mail: rfay@luc.edu (Richard R. Fay, director)

Rainbow Alliance of the Deaf (RAD)

Steven Schumacher, RAD Secretary

9804 Walker House Road, Suite 4

Montgomery Village, MD 20886-0506

Registry of Interpreters for the Deaf, Inc

333 Commerce Street

Alexandria, VA 22314

Phone: (703) 838-0030

Telecommunications for the Deaf, Inc (TDI)

8630 Fenton Street, Suite 604

Silver Spring, MD 20910

Voice: (301) 589-3786

TTY: (301) 589-3006

Fax: (301) 589-3797

E-mail: info@tdi-online.org

Triological Society (The American Laryngological, Rhinological, and Otological Society, Inc.)

555 North 30th Street

Omaha, NE 68131

Voice: (402) 346-5500

Fax: (402) 346-5300

E-mail: info@triological.org

USA Deaf Sports Federation (USADSF, formerly American Athletic Association of the Deaf [AAAD])

102 North Krohn Place

Sioux Falls, SD 57103-1800

Voice: (605) 367-5760

TTY: (605) 367-5761

E-mail: HomeOffice@usdeafsports.org

World Recreation Association of the Deaf, Inc (WRAD)

PO Box 3211

Quartz Hill, CA 93586

Videophone: (661) 943-8879

Additional patient education resources

For patient education resources, see the Ear, Nose, and Throat Center, as well as Hearing Loss.

 

Presentation

History

General presentation and age at detection

Before neonatal hearing screening was routine, deafness was diagnosed at a mean age of 2.5 years. Since the implementation of successful Universal Newborn Hearing Screening (UNHS) programs, this improved to a mean of 14 months, with 74% being diagnosed and receiving intervention by 6 months. Harrison et al reported the average age of diagnosis to be just 2-3 months.[26]

The goal is universal screening, aimed at detecting hearing loss prior to 3 months and initiating appropriate intervention prior to 6 months, in accordance with the Newborn and Infant Hearing Loss: Detection and Intervention policy statement from the American Academy of Pediatrics (AAP).[2]

In a screened population, the rate of referral for services before 6 months is 19 times higher than in an unscreened population. The rates for confirmation and management of hearing loss are five times higher and eight times higher, respectively, for a screened population.

In the unscreened population or for those with progressive or acquired hearing loss, parents are the first to suspect hearing loss in almost two thirds of the patients. Pediatricians detect roughly 10% of cases, and other healthcare providers suspect it first in approximately 15% of patients. The mean time from the first suspicion of hearing loss to its diagnosis is 9 months.

High-risk criteria for hearing loss in neonates and infants

Before the implementation of UNHS programs in most states, the high-risk criteria were an important tool in the early detection of hearing loss. However, the dissemination of high-risk criteria for neonates and infants in 1990 did not notably alter the mean age at diagnosis. About 50% of children with sensorineural hearing loss (SNHL) do not meet any of the criteria listed, and only 10% of neonates have one or more of the high-risk criteria that prompt an evaluation.

These rates were among the reasons cited for the need for universal neonatal hearing screening. However, these criteria (especially for age 29 days to 2 years) serve as a reminder for those children for whom providers should have an increased level of suspicion and a decreased threshold to refer for testing for missed congenital, progressive, or acquired hearing loss.

High-risk criteria for neonates (birth to 28 days) are as follows:

  • Family history of congenital or early SNHL
  • Congenital infection known to be associated with SNHL
  • Craniofacial anomalies
  • Birth weight below 1500 g (< 3.3 lb)
  • Hyperbilirubinemia over the exchange level
  • Exposure to ototoxic medications
  • Low Apgar scores at birth
  • Prolonged mechanical ventilation
  • Findings of a syndrome associated with SNHL

High-risk criteria for infants (29 days to 2 years) are as follows:

  • Concern about hearing, speech, language, or developmental delay
  • Bacterial meningitis
  • Neonatal risk factors associated with SNHL
  • Head trauma, especially with fracture of the temporal bone
  • Findings of a syndrome associated with SNHL
  • Exposure to ototoxic medications
  • Neurodegenerative disorders
  • Infectious diseases associated with SNHL

Indications for hearing evaluation and findings

Concern about a child's hearing loss expressed by a parent or caregiver always should prompt immediate evaluation. Hearing loss can be diagnosed at whatever age it is suspected, so delaying the diagnosis in the belief that a child is too young to be tested is unjustified. Other causes of language delay or behavioral problems should be considered as well, but hearing loss may be the cause of these problems. The results of referral for hearing loss are definitive, whereas evaluations for language or behavioral problems are more subjective and dependent on the skill of the person providing the evaluation.

Children with congenital or perinatally acquired profound SNHL (>90 dB) may present with loss of cooing by the age of 6-9 months and with frank language delay. Those with hearing loss less severe than this may present with minor speech impediments, language delay, behavioral problems, or school failure. The degree of hearing loss or loss of speech discrimination correlates with the patient's speech and language problems.

Behavioral problems may be major or minor, and they are probably best correlated with the child's personality and with how the parents deal with what they may consider a stubborn child. Before speech impediments, mental retardation, autism, attention deficit, or adjustment disorders are presumed, many children could benefit from a hearing evaluation.

Upon evaluation, a child who cannot hear normal speech can reproduce only what he or she hears. A child who cannot hear the teacher cannot learn. In addition, a child who is bored fidgets. A child who cannot understand and who is berated by caregivers for lack of cooperation may act out.

Healthcare providers should understand that normal speech volumes are 30-50 dB, whereas typical street traffic is about 60 dB. Standard phones ring and shouts register at approximately 80 dB, and lawnmowers are approximately 90 dB. Therefore, children with a 60-dB hearing loss hear their mother when she yells at them and startle when the telephone rings. However, they do not hear most conversational speech, and they may not always hear the teacher in a classroom, especially if they are not in the front and there is significant extraneous noise.

If children have poor speech discrimination, the diagnosis is usually made relatively early because they may mispronounce words or may be unable to understand what is being said. In children with good speech discrimination, hearing loss may go undetected because speech production and comprehension are less affected.

Children with mild hearing losses that begin prelingually or postlingually may present with difficulties late in childhood.

In general, children who lose their hearing postlingually present with a decline in language skills they had previously achieved. In children of this age group, clinically significant hearing loss is usually the result of an obvious medical event. Those who lose their hearing postlingually may be able to describe their loss. However, if the decline is gradual, they may not initially recognize the deficit.

Worsening speech or school performance may herald long-standing or progressive mild-to-moderate hearing loss. Other presentations of mild or progressive hearing loss may be withdrawal from social activities and playing alone, or playing the television and music with increasingly loud volumes.

Physical Examination

Children with congenital hearing loss should be carefully evaluated for any evidence of other physical stigmata or for possible associated syndromes (ie, a white forelock to suggest Waardenburg syndrome). (For a partial list of syndromes related to deafness, see Etiology.) Because almost every organ system can potentially provide evidence of an associated syndrome, detailed physical examination is necessary.

For patients with acquired hearing loss, an otolaryngologist should evaluate the ears by inspecting them for external defects or for obstructions that block sound conduction down the ear canal (eg, cerumen, foreign bodies). In addition, pneumatic otoscopy should be performed to detect any evidence of current or chronic infections, such as perforation or scarring of the tympanic membrane, cholesteatoma, abnormal landmarks, and fluid behind the tympanic membrane.

The remainder of the otolaryngology examination should be focused on the head and neck to carefully rule out other abnormalities that may lead to a diagnosis.

If children are old enough to cooperate, they should undergo tests of balance because dysfunction of the inner ear or vestibular nerve may also be present.

 

DDx

Diagnostic Considerations

No differential diagnosis for confirmed deafness is known, though differential diagnoses are generally considered in determining the etiology of hearing impairment. Alternatively, the differential diagnosis for children who present with language, behavioral, and school difficulties should include hearing loss.

 

Workup

Approach Considerations

At this time, accurate evaluation of hearing for children of all ages is possible. Therefore, if any adult involved in the care of a child suspects the possibility of hearing loss, an immediate referral should be made for appropriate diagnostic evaluation. Universal newborn screening does not rule out the possibility of a newly acquired hearing loss or a progressive loss that had been previously undiagnosed. The development of symptoms or physical examination findings consistent with a syndrome should be used to direct further diagnostic testing.

Laboratory Studies

Depending on the patient's history and physical findings, biochemical evidence or genetic testing may help determine the etiology of deafness if a genetic syndrome is suspected.

Some have recommended that for any child with a diagnosis of sensorineural hearing loss (SNHL), blood studies should be done to search for evidence of thyroid and renal disease. Such an evaluation involves testing thyroid function, measuring blood urea nitrogen (BUN) and creatinine levels, and urinalysis.

Connexin-26 is a marker for genetic deafness (DFNB1); therefore, a test for connexin-26 might be helpful.[8, 27, 28] This gene codes for GJB2 (a gap junction protein regulating the potassium concentration in the endolymph, which is important for signal transduction).

There are more than 150 distinct mutations of the gene. It has been said to account for 8-60% of nonsyndromic deafness in various populations.[29] In a European population, it accounted for 34-50% of autosomal recessive deafness and 10-37% of sporadic deafness (probably new mutations).[30] Its carrier frequency there was 2% of the general population. A similar prevalence was found in the midwestern United States, with the gene accounting for 42% of nonsyndromic deafness and a carrier frequency of 3%.[31]

For patients with acquired bilateral hearing loss, markers of general inflammatory disease (eg, erythrocyte sedimentation rate [ESR] or rheumatoid factor [RF]) or specific markers for autoimmune inner ear disease (eg, 68-kd protein) may be evaluated.

The yield of positive findings is low; however, laboratory studies are safe and inexpensive. Positive findings raise important considerations in the management of hearing loss.

Imaging Studies

In the past, the benefit of imaging studies has been questioned. Although a positive finding on magnetic resonance imaging (MRI) or computed tomography (CT) may occasionally help explain the defect, it does not lead to treatment options. However, some abnormalities uncovered during imaging (eg, enlarged vestibula aqueduct) may indicate a child with a sensitive ear in whom minor head trauma could worsen his or her hearing.

MRI may help in identifying a malformation of the cochlea or the cochlear nerve (see the image below). Such information may be critical when cochlear implants are being placed in profoundly deaf individuals. Some work suggests the superiority of MRI in preoperative planning for candidates for cochlear implants.[32]

Cochlear malformations. Neural foramen on the righ Cochlear malformations. Neural foramen on the right is absent. Right arrow indicates a rudimentary vestibule. On the left is a severe cochlear malformation (large arrow). Small arrow indicates the internal auditory canal.

Specific Tests for Hearing Loss

Before specific test results for hearing loss are reviewed, it is crucial to examine the Joint Committee on Infant Hearing (JCIH) updated position statement.[10, 33] Specifically, the JCIH recommended hearing screening in all infants by age 1 month; those who fail the initial test should have a thorough audiologic evaluation by age 3 months, with appropriate intervention by age 6 months.

In the update, the JCIH also included auditory neuropathy and dyssynchrony in the category of neural hearing loss.[34] Recommendations were also made regarding babies who remain in the neonatal intensive care unit (NICU) for longer than 5 days. These patients should undergo audio-evoked brainstem response testing rather than the otoacoustic emissions testing that frequently is used for newborn screening.

Specific tests for hearing loss include ABR (formally called the brainstem audio-evoked response [BAER] or automated ABR), otoacoustic emissions (OAEs), and audiometry.

The BAER is occasionally referred to as an ABR when it means audio-evoked brainstem response; in this case, the ABR is then called AABR for automated audio-evoked brainstem response. (BAER and ABR, the most common and least confusing abbreviations, are used in this article.)

ABR and BAER testing

ABR testing is based on the same principle as electroencephalography (EEG). When a hearing ear is given a stimulus, the resulting electrographic activity can be followed from the ear to central areas of the brain. In the formal testing procedure for BAER, clicks or specific frequencies at different volumes can be the stimuli.

Conductive hearing loss (CHL) cannot be distinguished from SNHL with the screening test, but formal BAER testing can be performed by using bone conduction testing. The sensitivity and specificity of this testing are near 100%. BAER tests frequently require sedation, and they take time and are expensive. Abnormal brain-wave activity (eg, seizure activity, significant prematurity, or movement artifact) can render the results uninterpretable.

Use of the automated testing procedure for ABR has been recommended for universal newborn hearing screening. Sound clicks are presented to each ear, and two electrodes placed on the scalp record brain-wave activity. An internal template of what the waveforms should resemble is used to determine if the baby passes the test (waveforms match) or not (waveforms do not match).

This is like the automatic readings that appear on many electrocardiography (ECG) devices, which include multiple stored templates that indicate a close match to normal sinus rhythm, right bundle-branch block, anterior infarct, or other conditions. Just as in ECG, muscle movement produces changes in the waveform; ECG reads these as artefactual, but the ABR reads them as "fail." Additionally, as with ECG, staff with relatively little training can perform the ABR test quickly and inexpensively. The test itself has a sensitivity of about 100% and a specificity of about 96%.

Because ABR reflects only nerve impulses that reach the brain, it cannot be used to distinguish CHL from SNHL. In neonatal screening, the false-positive rate can be as high as 10-15% because amniotic fluid and cellular debris are retained in the neonate's ear canal. Repeat testing is often completed before discharge from the nursery, but it is optimally performed after the fluid clears (up to 1 week). However, if the baby passes the repeat test, then it is very likely that he or she does not have a significant hearing loss.

As with the BAER, prematurity or seizure disorders may cause failing results on ABR testing because the abnormal brain-wave activity does not match the machine's internal template for passing results. In this case, formal BAER testing may be necessary because the important waves might be distinguishable from the background abnormalities when read by a trained professional. Use of the OAE is a reasonable alternative because does not depend on brain waves (except for NICU babies).

OAE testing

The concept of OAE is that certain sounds generated by the inner ear can be recorded. These sounds are present in ears that can hear and likely reflect the presence and function of structures responsible for hearing. The sounds may be spontaneous or evoked. How they are produced and why they are not produced in people with SNHL is unclear, but they are well correlated with hearing loss.

Also used for newborn screening, OAE tests can be performed quickly and inexpensively by personnel with relatively little training. An earphone is placed over the ear of a resting neonate, and the machine generates a sound and then records the evoked response. The sensitivity and specificity reported with evoked OAE are 100% and 82%, respectively.

By definition, OAE cannot be used to diagnose retrocochlear deafness, nor can it be used to distinguish CHL from SNHL. OAE had slightly elevated false-positive rates in most studies of neonatal hearing screening, probably because a sound must pass both in and out of the obstructed canal to be recorded. (With ABR, the sound only needs to enter in through the ear canal). OAE also seems to have a high failure rate when it is used in the NICU. For healthy term babies, the “two-step protocol” recommends that babies who fail an initial OAE may have follow-up testing with either another OAE or ABR testing.

Audiometry

Routine audiometry is performed by placing headsets over the ears of children whose developmental age is at least 4-5 years and who can be instructed to raise the corresponding hand when a sound is heard. Pure tone sounds can be presented so that specific volumes at specific frequencies can be documented. CHL and SNHL can be differentiated, and speech recognition can also be tested.

Audiometry is the criterion standard for patients with normal mental status and the ability to cooperate with the testing procedure. The only limits to the sensitivity and specificity of the test are the patient's ability to understand the instructions and his or her willingness to cooperate.

Pure-tone audiometry can be performed as a quick and easy screening test. It has proven to be an effective tool in schools. The disadvantages of pure-tone audiometry are that formal evaluation takes time and considerable equipment and that it can be fully performed only in older, cooperative patients.

Behavioral (visual reinforcement) and conditioned play audiometry can be completed in children as young as 6 months. Children can be conditioned to look at a puppet or a light show when a pure sound stimulus is presented or their name is called from one side of the room. If the evaluators are reliable, they can judge whether the child is cooperative and responding to cues other than the sound stimulus. In general, this test is fairly successful for identifying hearing loss in children. Disadvantages are that it requires considerable time and equipment, it cannot be used to distinguish CHL from SNHL, and it succeeds only if the child is cooperating.

Tests to avoid

Assessing responses to clapping, rattling keys, and snapping are poor tests of hearing. A child may respond to the visual or tactile stimulation rather than to the noise (eg, detect the slight breeze from a clap, accidental touching of the face with keys or fingers, or see the hands moving). Furthermore, the noise created is frequently more than 50 dB and, therefore, not useful in detecting mild and moderate losses.

A few companies market a small wand that produces white noise or a click at fixed or variable volumes. These wands have limited utility in rapid screening done in the office. However, if the time is taken to use them properly, they may provide some useful information.

Other Tests

ECG may be useful in diagnosing a prolonged QT interval, leading to a diagnosis of Jervell Lange-Nielsen syndrome. A prolonged QT may lead to cardiac arrhythmias, resulting in syncopal episodes or sudden death.

 

Treatment

Medical Care

Conductive hearing loss

Manage conductive hearling loss (CHL) due to otitis media or its sequelae with a course of appropriate antibiotics. Patients with serous otitis media for longer than 3 months benefit from myringotomy and removal of the fluid in the middle ear. Ventilation tubes may ultimately be necessary. If the hearing loss continues, amplification with a hearing aid may be needed. Speech therapy is rarely necessary unless the loss is prolonged and cannot be corrected with amplification.

CHL that results from obstruction of the auditory canal because of cerumen or a foreign body should be treated by removing the obstruction.

Sensorineural hearing loss

Sensorineural hearing loss (SNHL) cannot be treated medically.[35] In mild-to-moderate hearing loss, amplification with hearing aids is used to give the child as much auditory input as possible. Speech therapy may be beneficial. If the child requires special schooling, the school should determine how much speech training is routinely part of the school day. Preferential seating and use of FM systems should be discussed with the patient's family and teachers.

In older children and in adults with moderate-to-profound hearing loss, hearing aids may correct up to 40-60 dB. Beyond that, the limiting factor is the physical sound pressure exerted on the tympanic membrane, which becomes painful after a certain threshold. Young children with small ear canals may perceive pain at amplification volumes as low as 10-15 dB. Modern hearing aids can selectively amplify a specified range of frequencies more than others rather than all frequencies equally.

There are two main goals of amplification. The first is to provide language. After the hearing aid is fitted by using proper molds, the hearing aid is tested to see how well it matches the goals for loudness at various frequencies. With older children, speech recognition should be part of this testing. For young children, the goal is to optimize auditory input without causing pain. If the hearing aids are painful to use, children will avoid using them. If amplification is successful in providing improved spoken language comprehension without pain, its use in and out of school should be encouraged.

The second goal of amplification is to provide environmental cues. The use of hearing aids aids in connecting young children to their environment, helps maximize auditory language development if it allows them to hear any speech sounds, and uses auditory pathways to the brain, which may prevent the brain from “ignoring” them (as it does in cortically blinded laboratory animals). The ability to hear environmental sounds is important for safety and some general functioning. Important safety cues include car or truck horns, alarms, or even someone yelling “stop.” Functional cues might include class bells, oven timers, doorbells, or someone calling their name loudly.

Older children may choose not to use their hearing aids because they “don’t look cool.” Rather than making this a significant ongoing argument, parents should be reasonable. For example, if their child is succeeding in school, the hearing aids may not offer a substantial language benefit to their child’s functioning. Additionally, the child is likely safe in the classroom, so benefit might be gained by letting the child “win.” If the child prefers not to wear the hearing aids after school, parents should respect this decision if the child is participating in safe activities that do not pose an increased risk of harm because of missed environmental cues.

There is no medical disadvantage for children choosing to not use hearing aids. In fact, many deaf adults use their hearing aids selectively or not at all because they find that the extraneous noises and distortions they hear are more bothersome than helpful. They may decide to use their hearing aids only when they anticipate a particular benefit.

Surgical Care

Conductive hearing loss

Some causes of CHL may be managed or aided surgically. Children with persistent chronic or recurrent otitis media with resultant effusions may benefit from the placement of myringotomy tubes to ventilate the middle-ear space to prevent negative pressure in this area. If otitis results in the destruction or fixation of the ossicles, surgery may improve ossicular function. Cholesteatoma is a surgical disease.

Bone-anchored hearing aids (BAHAs) may be useful in some patients. Examples are patients with microtia, those with anotia who are awaiting auricular reconstruction, and patients with persistent otorrhea who cannot use a hearing aid.

Carter et al reported that an endoscopic transcanal approach to middle-ear exploration offered good visualization in pediatric patients with CHL and was especially helpful with apparently unexplained CHL in which ossicular deformity or fixation or discontinuity was suspected.[36] When the cause oif the CHL is definitively found, it can often be repaired in the same sitting.

Sensorineural hearing loss

SNHL cannot be treated with surgical means other than cochlear implantation. Cochlear implantation may be an option in some children, but it should not be mistaken for a cure.

Consultations

Otolaryngologist

Consulting an otolaryngologist is imperative if the child has CHL. An otolaryngologist can provide advice pertaining to medical and potential surgical interventions. Consultation is also recommended if the child has profound SNHL and is a potential candidate for cochlear implants. The otolaryngologist is a crucial member of the multidisciplinary team needed to help patients with profound SNHL.

Specialists in early intervention

Early intervention programs are essential to help parents understand how to raise a child who is deaf or hard of hearing. Such programs are also needed to begin discussing and implementing language and/or educational programs.

Audiologist

Consulting an audiologist is essential for evaluating patients for hearing aids and for fitting them.

Geneticist

Consultation with a geneticist is recommended if the cause of deafness may be syndromic or if the family history suggests a hereditary pattern.

Ophthalmologist, nephrologist, cardiologist, or other subspecialty consultants

Consulting these subspecialists is recommended if an identifiable syndrome implicates involvement of the visual, renal, cardiac, or any other organ system (eg, a deaf child with hematuria should see a nephrologist to check for Alport syndrome).

Similarly, if involvement of an organ system is anticipated because a child is diagnosed with a particular syndrome, a specialist may need to be involved (eg, a deaf child may benefit from aggressive ophthalmologic screening for the development of retinitis pigmentosa, as in Usher syndrome, or simply because vision is so important to communication that mild losses in visual acuity should be managed promptly).

Occasionally, a specialist may be able to identify abnormalities that may lead to the diagnosis of a specific syndrome that would not be seen without specialized equipment (eg, an ophthalmologist for a funduscopic examination or a cardiologist for electrocardiography [ECG] or echocardiography).

Because almost any organ system is potentially related to hearing loss, there is no need to consult every subspecialist for each child with hearing loss. As noted earlier, even routine ECG testing for a prolonged QT interval or laboratory testing for the development of nephritis or changes in blood urea nitrogen and creatinine are not recommended universally.

Experts in managing hearing loss

Consult physicians with expertise in caring for patients with hearing loss, if any are available in the community. Some physicians have developed expertise in the field of deafness and may be available for consultation. They can offer information about any associated medical conditions that may be present, as well as perspective about language and education, use of hearing aids and cochlear implants, and other equipment.

The literature is filled with debates about the most appropriate educational venues for children who are deaf or hard of hearing. Many people involved in early intervention are affiliated with a particular program because it matches their personal biases. Physicians with expertise in deafness may be more neutral. However, there is a clear bias in the literature towards spoken language as the outcome measure defining success, and relatively good literature about the success of an all-sign-language education (even the literature on reading ability can be questioned).

Long-Term Monitoring

Follow-up of the interventions is as important in hearing impairment as in any other disability or medical condition.[37] Physicians too frequently relegate the care of children who are deaf to audiologists and educators. Children who are deaf need ongoing referrals to an audiologist to monitor the progression of their hearing loss and to refit hearing aids so as to match changing losses, ear growth, or both.

Pediatricians should monitor the child's linguistic and social development. They should ask about language and school performance. The child's placement in school may not be optimal for his or her abilities. For instance, a child who is not successfully learning lip-reading cannot learn math or science. Pediatricians should ask how the child is doing in school and in the family, how family members interact with the child, and how the parents discipline or instruct the child.

Children who cannot communicate with those around them may be frustrated and, therefore, act out or display withdrawal behaviors. These behaviors may be misinterpreted as being a behavioral or psychological problem rather than being reactions to the child's environment or situation.

Children who are deaf or hard of hearing are at particular risk for abuse. Physical abuse may be inflicted by parents who are frustrated because their child is not acting as they expect. Also, children who perpetrators perceive as being unable to report misconduct are at high risk for sexual abuse. Furthermore, most children with hearing impairment have no physical disabilities and may be attractive to a potential perpetrator. Deaf children are sometimes socially isolated because of the communication barrier, and they may be susceptible to individuals who give them special attention. It is vital to watch for physical signs of abuse or for behavioral manifestations of child abuse.

 

Guidelines

ACMG Guideline for Evaluation and Diagnosis of Hearing Loss

In 2014, the American College of Medical Genetics and Genomics (ACMG) published a guideline that provided information about the frequency, causes, and presentations of hearing loss and suggested approaches to clinical evaluation aimed at identifying an etiologic diagnosis of hearing loss.[14]  Recommendations included the following:

  • All newborns and infants with confirmed hearing loss should undergo a comprehensive evaluation that includes patient-focused medical and birth histories and a three-generation pedigree and family medical history are obtained, as well as a physical examination focusing on dysmorphic physical findings; evaluation of children and young adults with hearing loss should follow a similar approach.
  • Elements of medical and birth histories focused on hearing loss include prenatal history (eg, maternal infections and illnesses or medication or drug exposures); neonatal history (eg, premature birth, low birth weight, birth hypoxia, hyperbilirubinemia, sepsis, and exposure to ototoxic medications); postnatal history (eg, viral illnesses, bacterial meningitis, head trauma, noise exposure, and exposure to ototoxic medications); and audiometric assessment of the hearing loss.
  • The pedigree and family medical history should focus on identifying the following: first- and second-degree relatives with hearing loss or with features commonly associated with hearing loss (eg, pigmentary, branchial, or renal anomalies) or sudden cardiac death; a pattern of inheritance; ethnicity and country of origin; common origin from ethnically or geographically isolated areas; and consanguinity.
  • The physical examination should focus on dysmorphic and other physical findings (eg, unusual facial appearance, with attention to asymmetry; pigmentary anomalies; neck, skin, facial, or ear anomalies; neurologic abnormalities; balance disturbances; and skeletal abnormalities).
  • For individuals with findings that suggest a syndromic genetic etiology for their hearing loss, pretest genetic counseling should be provided, and, with informed consent, genetic testing, if available, should be ordered to confirm the diagnosis; appropriate studies should be undertaken to determine whether other organs are involved; appropriate near-term and long-term screening and management should be arranged as indicated by the associated manifestations of the particular syndrome.
  • For individuals lacking physical findings suggestive of a known syndrome and having medical and birth histories that do not suggest an environmental cause of hearing loss, a tiered approach is advisable; pretest genetic counseling should be provided, and, with informed consent, genetic testing should be ordered; temporal bone imaging by CT or MRI should be considered as a complement to genetic testing; cytomegalovirus (CMV) should be done at the same time as genetic testing for infants with congenital hearing loss (for later-onset or progressive hearing loss, the likelihood that a positive CMV test result is due to postnatal exposure increases with age).
  • Referral to a multidisciplinary care center, when available, is recommended; a team approach that includes otolaryngologists, clinical geneticists, genetic counselors, audiologists, speech and language specialists, early hearing intervention and family support specialists, and other appropriate specialists is optimal.
  • When genetic evaluation has failed to identify an underlying cause, periodic follow-up care every 3 years with a geneticist may be appropriate.
  • Regardless of whether genetic test results are positive, negative, or inconclusive, results should be communicated through the process of genetic counseling.
 

Medication

Medication Summary

No medical therapy is specifically available for deafness. Only some etiologies of CHL may be managed medically.