# Hearing Aids and Implants > Hearing aids and implants for NEET-PG ENT: device selection, cochlear implant candidacy, BAHA and brainstem implants in one exam-focused revision note. - Canonical URL: https://prepelephant.com/topics/neet-pg/ent/hearing-aids-and-implants - Exam / course: NEET-PG · Subject: ENT - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Hearing Aids and Implants", PrepElephant, https://prepelephant.com/topics/neet-pg/ent/hearing-aids-and-implants ## Direct answer A hearing aid helps when cochlear reserve remains; an implant takes over when it does not. Air-conduction behind-the-ear and in-the-ear aids, and bone-conduction devices for ears that cannot be fitted, restore audibility in residual hearing, while a cochlear implant bypasses dead hair cells entirely by electrically stimulating the spiral ganglion — the treatment of choice for bilateral severe-to-profound sensorineural loss with poor benefit from amplification. The dividing line is aided performance, not the bare audiogram: a child or adult who fails to derive speech understanding from a well-fitted trial of hearing aids is an implant candidate, and in congenitally deaf children the clock matters, because implantation around the age of one year rides the critical period of speech and language development. ## What you must remember - Basic aid styles, from most to least visible: body-worn, behind-the-ear (BTE), in-the-ear (ITE), in-the-canal (ITC) and completely-in-the-canal (CIC); smaller is cosmetically better but delivers less power and fewer directional features. - Digital aids allow programmable gain per frequency, noise reduction, directional microphones and feedback cancellation — the standard of care, not a luxury. - Hearing aids suit conductive loss (when surgery is refused or failed) and sensorineural loss with usable speech discrimination; they cannot restore clarity that the cochlea cannot encode. - Bone-conduction devices (bone-anchored hearing aids and soft-band systems) serve conductive or mixed loss with an unusable ear canal — aural atresia, microtia, chronically discharging ears — and single-sided deafness. - Middle ear implants (such as the Vibrant Soundbridge) help sensorineural or mixed loss when conventional aids are not tolerated. - Cochlear implant candidacy in broad terms: bilateral severe-to-profound sensorineural loss, limited aided benefit, historically from about 12 months of age in children, with no cochlear aplasia (auditory nerve must be present) and family commitment to habilitation. - Components: an external microphone, speech processor and transmitting coil over an internal receiver–stimulator and electrode array inserted into the scala tympani via a round window or cochleostomy. - Auditory brainstem implant exists for neurofibromatosis type 2 patients whose both VIII nerves are sacrificed — electrodes stimulate the cochlear nucleus at the floor of the fourth ventricle. ## Choosing the device, walked through like a clinic list Work the decision in three questions. First, is the loss conductive or sensorineural? A patient with long-standing otorrhoea and a 40 dB conductive loss has two options — surgery to reverse the cause, or a hearing aid. If the canal cannot hold an ear mould because it never stops discharging, a bone-conduction device transmits sound directly through skull bone to the better cochlea and sidesteps the canal altogether. The child with congenital aural atresia is the textbook case: normal inner ear, no canal, ideal for a soft-band device in infancy and bone-anchored fixation once skull thickness permits. Second, if sensorineural, how much speech does the patient still extract? Fit a properly programmed aid, allow weeks of adaptation, then test aided speech perception. A 60-year-old with presbycusis who scores well when amplified keeps the aid; a post-lingually deafened adult who hears sound but understands almost nothing despite amplification crosses into implant territory, because electrode arrays replace, not assist, the transducer function. Third, what is the timeline? Pre-lingual deafness is an emergency of language. Universal newborn screening with otoacoustic emissions, followed by auditory brainstem response, should have every congenitally deaf child amplified within months and implanted around the first birthday in eligible cases; after the critical window closes, even a perfectly placed electrode yields sound without meaning. Post-lingually deafened adults are the opposite — their auditory cortex is wired for speech, so they rehabilitate quickly even when implanted years later. ## How the exam frames it Question writers love the mismatch between audiogram and device. A stem describes a busy executive with high-frequency presbycusis who complains that "everyone mumbles in meetings" — that is reduced speech clarity from outer hair cell loss, helped by high-frequency emphasis and directional microphones, not by more raw power. Another favourite is the NF2 patient after bilateral vestibular schwannoma excision: a cochlear implant is useless because the auditory nerves are gone, and only an auditory brainstem implant applies. Expect also the child with single-sided deafness (SSD) — options are a contralateral routing of signal (CROS) aid or a bone-conduction device, which delivers signal across the skull to the hearing side. Finally, remember the complications examiners probe: device failure, flap infection or extrusion, and the small meningitis risk that makes pneumococcal vaccination standard before implantation. ## Frequently asked questions ### When does a patient qualify for a cochlear implant rather than a hearing aid? Bilateral severe-to-profound sensorineural loss with speech perception that remains poor despite a well-fitted trial of hearing aids — candidacy is judged by aided performance, not the audiogram alone. ### Why is early implantation emphasised in congenital deafness? Language develops within a critical period in early childhood; implantation around one year of age allows electrical hearing to shape the auditory cortex while plasticity is high, whereas late implantation of a pre-lingually deaf child yields poor language outcomes. ### Which device suits a child with aural atresia and a normal inner ear? A bone-conduction device on a soft band in infancy, later a bone-anchored hearing aid; it bypasses the absent canal and drives the functioning cochlea through skull bone. ### What is an auditory brainstem implant and when is it used? An electrode array placed on the cochlear nucleus in the lateral recess of the fourth ventricle, used when both auditory nerves are unavailable, classically in neurofibromatosis type 2 after bilateral acoustic tumour excision. ### Why do hearing aids fail to restore clarity in severe cochlear loss? Amplification raises audibility, but distorted hair cell encoding means louder sound arrives garbled; when discrimination scores collapse despite amplification, no hearing aid can compensate.