Amplification Options in the Treatment of Auditory Neuropathy

Abstract

Summary There is no consensus withinthe audiological community con-cerning the efficacy of amplificationfor patients with AN. Until more isknown about the subcategories ofAN and their characteristic re-sponse to amplification, it seemsprudent to address each case indi-vidually. One suggested approachis to provide a carefully monitoredtrial period with amplification inaccordance with the patient’s be-havioral thresholds.When an infant’s test findingsare consistent with AN, immediatereferrals should be made to earlyintervention services, otology, oph-thalmology, and medical genetics.This is the same group of referralsthat would be made when senso-rineural hearing loss or mixed hear-ing loss is identified. What differsbetween referrals for patients withAN and referrals for more typicalhearing loss is that amplificationmay be deferred until behavioralaudiometric findings are obtainedand stability of thresholds is estab-lished.Some patients may present witha combination of findings suggest-ing AN as well as a sensory hear-ing loss. These patients exhibit mea-surable OAEs and cochlear micro-phonics, absent middle ear reflexes,and measurable Wave Vs on theABR that are consistent with ob-served auditory responsiveness. Ifthese individuals are not able toperform behavioral audiometry, theABR thresholds could be used as afirst approximation of behavioralthresholds. These initial Wave Vthresholds or behavioral thresholdswould be used in a systematic am-plification protocol (Pediatric Work-ing Group, 1996). For older children and adultswho can provide input about audi-bility, comfort, and quality, pre-scriptive approaches can be modi-fied in accordance with their sub-jective reports. For young children,indispensable information to guidethe fitting process is obtained fromthe observations of parents,caregivers, and early intervention-ists. Monitoring of auditory respon-siveness, in combination with closemonitoring of thresholds and OAEs,is critical during the amplificationtrial period. The length of the trialwith amplification will vary on acase-by-case basis. Finally, regard-less of the etiology of hearing loss,amplification must be used in com-bination with a comprehensive re-habilitation program.