Hearing loss in children: Treatment

INTRODUCTION — Hearing loss in childhood that is undetected and untreated can result in speech, language, and cognitive delays. Early identification and effective treatment of hearing loss improves language, communication, and cognitive skills [1-5].

The treatment of hearing loss in children is reviewed here. The etiology and evaluation of hearing loss in children are discussed separately. (See "Hearing loss in children: Etiology" and "Hearing loss in children: Screening and evaluation".)

MULTIDISCIPLINARY APPROACH — Ideally, all children with permanent hearing loss should be managed by a multidisciplinary team that includes audiologists, otolaryngologists, speech pathologists, clinical geneticists, genetic counselors, and educational specialists. In addition, these children should be referred to a pediatric ophthalmologist because they rely on sight for communication and learning [6].

The hearing-impaired child should also be referred to the appropriate educational agency. In some states, referral is mandatory within a limited time after identification. The local school district or early childhood intervention agency is equipped to provide educational guidance for the special needs of hearing-impaired children. This may include preferential seating or the use of frequency-modulated (FM) systems at school. (See 'Assistive listening devices' below.)

Educational options vary according to the degree of hearing loss and cognitive ability of the child. Development of communication skills is the basic goal of early education programs for hearing-impaired children. Most agencies work with the team of professionals to establish an individual treatment plan for each child.

MANAGEMENT OF UNDERLYING CONDITIONS — The first step is to treat the underlying etiology if possible. Some conditions associated with hearing loss are amenable to surgical intervention:

●Recurrent acute otitis media and middle ear effusion – Tympanostomy tube placement may improve hearing for children with middle ear effusion, Eustachian tube dysfunction, or recurrent acute otitis media. (See "Overview of tympanostomy tube placement, postoperative care, and complications in children" and "Acute otitis media in children: Prevention of recurrence", section on 'Tympanostomy tubes' and "Otitis media with effusion (serous otitis media) in children: Management", section on 'Tympanostomy tubes'.)

●Tumors and cholesteatomas require surgical excision or mastoidectomy. (See "Cholesteatoma in children".)

●Perilymph fistula – Children with fluctuating or progressive sensorineural hearing loss may occasionally benefit from surgical exploration for and repair of a perilymph fistula. (See "Causes of vertigo", section on 'Perilymphatic fistula'.)

Some conditions that cause conductive hearing loss can be treated with either surgery or amplification (see "Congenital anomalies of the ear"):

●Stapes footplate fixation or other ossicular chain abnormalities

●Stenosis of the external auditory canal

●Some cases of atresia of the external auditory canal [7]

HEARING AIDS AND ASSISTIVE DEVICES — The next step in the management of hearing loss, after the underlying etiology is addressed when possible, is hearing amplification. The initial stage in providing successful hearing amplification is for the audiologist and the parents, child, and other family members to agree that the child has hearing loss and will benefit from a hearing aid. A second opinion is sometimes necessary to convince the parents of this fact. Parents should know that hearing aids do not necessarily restore hearing to normal, but improved hearing is expected. Amplification before the age of six months improves language outcome [8,9].

Hearing aids

Selection and fitting — A wide range of hearing aids is available, with selection based on audiologic evaluation, age, degree and type of hearing loss, and patient/family preference. In young children, to verify that a hearing aid fits well and is not too loud, sound intensity can be measured in the ear canal using a tiny microphone (real-ear). Computer algorithms are also available that use real-ear measurements (or simulated real-ear measurements) to determine whether a particular aid is appropriate for a given child. In very young children, the desired sensation-level approach is used to estimate the frequency gain needed to amplify speech to audible levels across a broad frequency range [10,11].

Style — The styles of hearing aids available include bone conduction, behind-the-ear, in-the-ear, and completely-in-the-canal instruments. Bone conduction hearing aids are used for children who have atretic ears or chronic otorrhea. (See 'Bone conduction hearing devices' below.)

Most hearing aids fit for children are behind-the-ear instruments because the ear mold that is coupled to the ear is easily remade as the child grows. In-the-ear and in-the-canal instruments are more cosmetically appealing to teenagers. These devices are appropriate only for hearing loss less than 60 decibels (dB).

Electronic features — A variety of electronic circuitry and signal processing options are available. Circuitry can be analog, digital, or digitally programmable. Although digital and programmable hearing aids are more expensive than analog hearing aids, they offer the benefits of better sound quality, increased precision, improved speech recognition [12,13], and flexibility of settings.

One important example is hearing in noise. Single-microphone noise reduction (SMNR; also known as digital noise reduction) is used to suppress background noise [14]. Background noise is defined as unwanted or competing acoustic signals when a signal of interest such as speech or music is present. Most hearing aid users have difficulties hearing in settings where there is considerable background noise such as playgrounds and open classrooms. Background noise, like all acoustic signals, has temporal, spectral, and amplitude features, the characteristics of which can be recognized and then suppressed to improve the auditory signal. In one report, SMNR was activated approximately 20 percent of the time when worn by hearing aid users over a period of four to five weeks [15]. This suggests that SMNR may benefit older children. There have been no studies testing the effect of SMNR on infants and young children.

Digital hearing aids are generally not appropriate for children with profound hearing loss; however, several programmable aids provide adequate gain for children with severe to profound losses.

Assistive listening devices — Assistive listening systems improve hearing perception, especially in noisy environments. They consist of a microphone for the speaker, a frequency-modulated (FM) transmitter, and a receiver worn by the listener. These are available as standalone units, or the FM receiver can be attached to a hearing aid [16]. Assistive listening systems provide gain (amplification) and improve signal-to-noise ratio by eliminating background noise. Most FM assistive devices are used for educational purposes, but they can help in other listening situations.

Follow-up — Regular follow-up with an audiologist and otolaryngologist is important to establish aided benefit and to serially reassess the fit of the hearing aids and ear mold.

BONE CONDUCTION HEARING DEVICES — Some patients who are unable to benefit from a standard air conduction device (a conventional hearing aid) may benefit from a device that transmits sound directly through the skull. Bone conduction hearing aids can be held against the skull with a steel spring or soft headband. Improvements in design have led to instruments that are more comfortable and provide better sound. However, an implantable bone conduction hearing aid still has significant advantages [17-21].

The main implantable system available is a bone-anchored implantable hearing aid system (BAHA). A small titanium screw is inserted into and osseointegrates with the bone of the skull over several months. An abutment is attached to the screw such that a small portion of the abutment sticks out through the skin and forms an attachment point for a removable bone conduction hearing aid. The sound quality is superior to that of traditional bone conduction hearing aids. Other implantable systems that directly vibrate the ossicles in the middle ear are also available [22,23].

Potential indications for an implantable system include:

●Congenital atresia of the ear canal such that it does not exist or cannot accommodate a standard hearing aid (provided that the nerve is functional) [24-26]. (See "Congenital anomalies of the ear", section on 'Aural atresia (external auditory canal atresia)'.)

●Chronic infection of the middle or outer ear that is exacerbated by a standard hearing aid.

●Allergic reactions to standard hearing aids.

●Single-sided deafness, as may occur after removal of a vestibular schwannoma (acoustic neuroma), from trauma, or from a viral or vascular insult [27].

Children are typically approximately six years of age before a BAHA is feasible because 3 to 4 mm of bone is needed to ensure osseointegration [28]. The BAHA may be implanted either unilaterally or bilaterally [29]. A systematic review of observational studies of BAHA in both children and adults found greater audiologic benefits (eg, hearing sensitivity in quiet, speech perception in quiet and in noise, and localization/lateralization) in patients with bilateral compared with unilateral placement [30].

COCHLEAR IMPLANTS

Indications and devices — Cochlear implants are surgically implanted prosthetic devices that electrically stimulate the cochlear nerve to provide hearing. The device consists of a battery-powered external processor (that looks like a hearing aid), a receiver coil implanted below the scalp, and an electrode inserted directly into the cochlea through a surgical opening.

The criteria for selecting candidates for cochlear implantation have expanded and continue to evolve. The minimum age for implantation has progressively dropped as implantation at an early age provides superior outcomes. In addition, bilateral implantation offers better sound localization and enhanced ability to understand speech in noisy environments. Deafened children with a variety of additional challenges such as developmental delay, inner ear malformation, cochlear nerve deficiency, and postmeningitic cochlear ossification can also be successfully implanted, although candidacy must be individualized and post-implantation rehabilitation can be more challenging [31-34].

Cochlear implant devices (including those from Advanced Bionics, Med-El, and Clarion) are approved by the US Food and Drug Administration for use in children as young as 12 months, although off-label use has been offered to infants <12 months old [35]. The advantage of early auditory stimulation during the "critical period" of hearing development needs to be balanced against the risks of the procedure. Studies supporting use of cochlear implants in infants <12 months of age are discussed below. (See 'Language and development' below.)

Bilateral cochlear implants have been advocated as they allow a child to hear better in conditions with background noise (such as playgrounds and open classrooms), localize sound, and hear sound coming from either side without having to turn the head [36-38]. Arguments against bilateral implantation include increased surgical and anesthetic risk, risk to residual hearing, and saving one ear for future technologies. If chosen, bilateral implants are either performed at one operative procedure or sequentially in separate surgeries. Studies demonstrate benefit from bilateral implantation with any length of time between surgeries [39]; however, improved response at the brainstem and greater expressive language development is noted in patients with minimized duration between implants, with the greatest response seen in patients with simultaneous implantation [36,40,41].

Preoperative evaluation — Preoperative evaluation for a cochlear implant includes computed tomography or magnetic resonance imaging (MRI) of the temporal bone to evaluate the patency of the cochlea, identify congenital malformations, and assess surgical anatomy [42]. Audiometric testing should be well documented. Other important prerequisites include access to an education program that stresses auditory and verbal skills and highly motivated parents who have realistic expectations. Because of the increased risk of meningitis in children with cochlear implants, immunization against Streptococcus pneumoniae and Haemophilus influenza is recommended. (See "Cochlear implant infections".)

Outcome

Language and development — Cochlear implantation provides auditory detection over much of the speech signal and results in improved auditory discrimination, language comprehension, and speech production compared with hearing aids [34,42,43]. Language outcomes are best among children who are implanted at an early age, those with delayed onset of hearing loss (eg, onset after age two to three years), those who have been deaf for a relatively short time, and/or those who have spoken language skills before implantation [44-49].

●Infants <12 months old versus older children – Most studies suggest that early cochlear implantation (at age <12 months) results in similar or better auditory outcomes compared with later implantation. A systematic review identified 17 studies describing hearing outcomes in 642 infants (ages 2 to 12 months) [50]. All studies documented improvement in hearing following placement of cochlear implants. In the nine studies that compared implantation in infants <12 months versus children ≥12 months, eight studies found that earlier placement of cochlear implants achieved comparable or better auditory outcomes.

Among prelingually deaf children (ie, those with onset of deafness before developing spoken language skills, including congenital and early-onset [before three years of age] deafness), speech perception improves gradually over time following cochlear implantation. This was demonstrated in a study of 40 prelingually deaf children who underwent cochlear implantation [49].Before implantation, children in this study had no measurable speech perception with the most powerful hearing aids. At two years after cochlear implantation, speech perception had improved to a mean of 27words per minute, and by five years it had improved to 45 words per minute. Improvement in speech perception was greater for children who were younger at the time of implantation and who used spoken, rather than total, communication (eg, including signing).

●Children with developmental delay – Cochlear implantation appears to benefit deaf children with and without developmental delay (DD), though outcomes are generally better among children without DD at the time of implantation. This was demonstrated in a study that prospectively followed 204 deaf children, of whom 138 did not have DD at baseline and were managed with cochlear implantation, 37 had DD at baseline and were managed with cochlear implantation, and 29 had DD at baseline and were managed with hearing aids [34]. After an average follow-up of two years, children without DD at baseline who were managed with cochlear implantation had the highest scores on standardized developmental testing, while children with DD at baseline who were managed with hearing aids had the lowest scores. When developmental trajectories were assessed over time, children with DD managed with cochlear implantation outperformed those with DD managed with hearing aids on all assessments, including cognition, adaptive behavior, language, and auditory skills. These findings support the practice of undertaking cochlear implantation at an early age (ie, before the child shows signs of DD); however, they also highlight that the presence of DD is not a reason to forgo cochlear implantation.

●Risk factors for poor language outcomes – Audiologic and language outcomes may be poorer in children with congenital cytomegalovirus infection [51], hypoplastic inner ear malformations, and/or cochlear nerve deficiency [52]. In addition, severe inner ear dysplasia is associated with increased surgical difficulty, including a higher rate of intraoperative cerebrospinal fluid gushers [53,54].

Other outcomes — Educational and employment achievements were examined in a series of 100 prelingually deaf children who received cochlear implants before six years of age and were followed for at least four years after implantation [55]. Most children without additional disabilities were in mainstream schools. Approximately one-quarter experienced delayed reading and writing skills, and approximately one-half repeated a grade. Despite this, the educational and employment levels ultimately achieved in this group were comparable with that of their peers with normal hearing.

Implant failure — Cochlear implant failure, due to medical complications (infection or wound dehiscence) or device failure, is rare; children with a history of meningitis as the cause of deafness are at increased risk [56-60]. (See 'Long-term complications' below and "Cochlear implant infections".)

Long-term complications — Patients with cochlear implants require lifelong follow-up to monitor for potential complications and to facilitate care if complications occur. In a meta-analysis of 88 studies including >22,000 adult and pediatric patients with cochlear implants, long-term complications occurred in 6 percent [61]. The most common complications included:

●Vestibular complications (eg, dizziness, balance problems) – 4 percent

●Device failure – 3 percent

●Taste problems – 3 percent

●Electrode problems – 2 percent

●Mastoiditis – 1.4 percent

●Skin infections – 1.3 percent

●Device rejection – 1.0 percent

●Seroma or hematoma – 0.9 percent

●Recurrent otitis – 0.8 percent

●Device migration – 0.7 percent

●Facial nerve palsy – 0.6 percent

●Cholesteatoma – 0.5 percent

The rates of postoperative and long-term complications do not appear to differ between children who undergo cochlear implantation at a young age (<12 months) compared with at a later age [62].

Risk of meningitis — Children with cochlear implants are at increased risk for meningitis, particularly pneumococcal meningitis. This issue is discussed in detail separately. (See "Cochlear implant infections".)

Modification of activities — Patients with cochlear implants are able to participate in most sports [63]. Patients must remove the external speech processor for activities including water sports and must be cautious of their lack of hearing during these activities. Many advise against scuba diving because of rapid changes in pressure that may occur in the middle ear, though some case reports describe scuba diving by cochlear implant patients [64]. Sports with the risk of head contact, such as kickboxing or wrestling, are also not advised, as they may disrupt the implant.

MRI may cause displacement of the internal magnet and can cause pain or discomfort in patients with cochlear implants [65]. Some newer cochlear implants are MRI-safe, although the external processor must be removed [66]. Other implants require a local surgical procedure to remove the internal magnet. The specific model of the cochlear implant and MRI machine must be verified to ensure the safety of the patient and implant prior to undergoing MRI.

RESOURCES FOR FAMILIES — MyDeafChild.org and the Chicago Hearing Society are organizations that provide information for parents of children with hearing loss.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Hearing impairment in infants and children".)

SUMMARY AND RECOMMENDATIONS

●Importance – Hearing loss that is undetected and untreated can result in speech, language, and cognitive delays. Early identification and effective treatment of hearing loss improves language, communication, and cognitive skills. (See 'Introduction' above.)

●Referrals – Children with permanent hearing loss should be managed by a multidisciplinary team that includes audiologists, otolaryngologists, speech pathologists, geneticists, genetic counselors, and educational specialists. They should also be referred to a pediatric ophthalmologist because they rely on sight for communication and learning. (See 'Multidisciplinary approach' above.)

●Addressing underlying conditions – Surgical intervention is indicated for some conditions associated with hearing loss (eg, tumors, cholesteatomas). Some conditions that cause conductive hearing loss can be treated with either surgery or amplification (eg, stapes footplate fixation and other ossicular chain abnormalities, and stenosis or atresia of the external auditory canal). (See 'Management of underlying conditions' above.)

●Hearing aids – Hearing aids are the primary form of amplification devices used. Hearing aids improve hearing but do not necessarily restore it to normal. Amplification before the age of six months improves language outcome. (See 'Hearing aids and assistive devices' above.)

●Bone conduction hearing aids – Bone conduction hearing aids are devices that transmit sound directly through the skull. Bone conduction hearing aids are used in patients who are unable to benefit from a standard air conduction device (a conventional hearing aid), such as those with congenital aural atresia. They are held against the skull or are bone-anchored. The latter method is preferred, but it is generally not feasible to place a bone-anchored implantable hearing aid system (BAHA) before the age of approximately six years, because 3 to 4 mm of bone is needed to ensure osseointegration. The BAHA may be implanted either unilaterally or bilaterally. (See 'Bone conduction hearing devices' above.)

●Cochlear implants – Cochlear implants electrically stimulate the cochlear nerve to provide hearing. For patients with profound bilateral sensorineural hearing loss who have had little or no benefit from hearing aid use after six months, we recommend cochlear implants (Grade 1B). We suggest bilateral, rather than unilateral, implantation, minimizing the time between implants (Grade 2C). (See 'Indications and devices' above.)