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Hearing aids, bone-conduction devices and cochlear implants

Choose and explain hearing rehabilitation according to auditory function and individual goals, recognise cochlear-implant assessment criteria, and provide practical device aftercare and safety advice.

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Device use does not remove clinical emergencies

A hearing-device user may have a new medical hearing problem, an implant-site complication or a hazardous battery incident.

Action: Assess a sudden unexplained hearing decline through the urgent ENT pathway rather than assuming device failure. Seek prompt implant-team advice for a painful, loose or discharging abutment or damaged skin under a magnet. Suspected swallowing or insertion of a hearing-device battery into an ear or nose requires immediate emergency-department assessment.

Open the sections you need. The overview is shown first.
01Purpose and principlesWhat the treatment does and how it fits into care.

Hearing rehabilitation is a process of matching the person's auditory function, listening demands and preferences to a suitable strategy. A device is only one part of that process. An adult who struggles with meetings may need improved access to the speaker, an appropriate hearing aid and a remote microphone, while someone with profound loss and little benefit from acoustic amplification may need specialist implant assessment. Explain the purpose of each option before discussing its size or appearance.

Conventional hearing aids process and amplify sound delivered through the ear canal. Their fitting is tailored to the measured loss and the user's comfort. They can improve access to speech and environmental sounds without recreating normal hearing in every situation. Acclimatisation and adjustments are often needed. A person who reports poor benefit should be asked about fit, device function, usage, hearing change and the particular settings in which the problem occurs.

Bone-conduction devices transmit vibration through the skull. In an ear with a transmission problem, this can provide access to a functioning cochlea while avoiding an unsuitable canal route. In single-sided deafness, the sound may be routed from the deaf side to the opposite functioning cochlea. Surgical and non-surgical options exist, including processors worn on a band for assessment or continued use. Implant suitability requires assessment of hearing reserve, anatomy, skin and the person's willingness to undertake surgery and aftercare.

A cochlear implant converts sound into an electrical pattern delivered by an electrode system within the cochlea, with the aim of stimulating the auditory pathway when acoustic amplification provides insufficient benefit. Assessment examines both unaided hearing and what appropriately fitted aids actually achieve. Surgery is followed by processor programming and rehabilitation rather than immediate restoration of ordinary hearing. Patients need an opportunity to discuss expected benefit, uncertainty, practical commitments and alternatives with the multidisciplinary team.

Key points

  • Offer hearing aids when hearing loss affects communication, awareness of warnings or other important listening activities.
  • If both ears have aidable loss, offer two hearing aids and explain the likely benefits of bilateral support.
  • Bone-conduction devices bypass parts of the external and middle-ear route; their value depends on cochlear reserve, ear anatomy and the listening problem.
  • A CROS system transfers sound from the poorly hearing side to the better ear; it does not restore independent sensory hearing in the poorer ear.
  • NICE TA566 cochlear-implant criteria combine severe-to-profound bilateral thresholds, inadequate acoustic-aid benefit and multidisciplinary assessment.
  • Device fitting needs instruction, follow-up, maintenance and realistic goals, with a route back to audiology when benefit is inadequate.
02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.
An adult likely to benefit from conventional aids

NICE bases offering aids on the effect of hearing loss on communication and important listening activities. Two aids should be offered for bilateral aidable impairment. Dexterity, vision, comfort, cognition and the ability to manage small components influence the practical choice and teaching approach.

A possible bone-conduction candidate

An unsuitable ear canal, chronic problems with conventional mould use or a conductive or mixed hearing problem may justify specialist assessment. Some people with single-sided deafness also benefit from routing sound to the functioning cochlea. Trial use can help establish whether the benefit matches the patient's goals.

Inadequate benefit despite acoustic amplification

Check whether hearing aids have been appropriately fitted and used before concluding that amplification has failed. Poor speech access in severe-to-profound bilateral loss may support referral for cochlear-implant assessment. A patient who was previously unsuitable can be reassessed if hearing or speech understanding declines.

A practical or medical device problem

Distinguish a blocked tube, depleted battery, poor retention or uncomfortable mould from a new ear disease. Inspect the skin around an implant and under a magnet. Sudden hearing deterioration or new discharge should not be managed solely by changing processor settings.

Red flags requiring action

  • New sudden hearing loss, neurological signs or severe vertigo requires clinical assessment even if the person already uses hearing aids.
  • Redness, pressure injury, discharge or loosening around an implanted device needs prompt specialist advice; do not simply increase magnet strength or continue wearing it over injured skin.
  • An implanted hearing device requires exact model identification and MRI safety checking before scanning; removing the external processor alone does not establish that the internal implant is safe.
  • A missing battery with possible ingestion or placement in an ear or nose requires emergency assessment, including for small zinc-air batteries.
03Assessment before treatmentTests and checks that guide safe selection.
Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

  1. 01
    Audiological assessment and personal listening goalsFirst step
    Why
    Establish the impairment, medical referral needs and desired practical outcomes.
    Interpretation and limitations
    Take a relevant history, examine the ears and obtain pure-tone results with tympanometry when indicated and safe. Discuss communication settings and current strategies so that device selection addresses the problems the person actually wants to solve.
  2. 02
    Hearing-aid fitting and benefit assessment
    Why
    Determine whether appropriately adjusted acoustic amplification provides useful access to sound.
    Interpretation and limitations
    Assess comfort, handling, listening performance and the adequacy of current settings. NICE recommends reviewing the new fitting at six to 12 weeks. Poor benefit can reflect a correctable device issue, an unsuitable strategy or hearing beyond the useful range of that aid.
  3. 03
    Bone-conduction assessment and trial
    Why
    Explore whether bypassing the canal route or routing sound to the opposite cochlea is useful.
    Interpretation and limitations
    The specialist team evaluates hearing, anatomy and the suitability of different devices. A temporary headband trial can inform expectations before implantation, while imaging is used when needed to plan the procedure. A successful trial does not remove the need to discuss skin care and surgical risks.
  4. 04
    Cochlear-implant multidisciplinary assessment
    Why
    Assess candidacy using thresholds, aided performance and individual circumstances.
    Interpretation and limitations
    TA566 defines severe-to-profound deafness as unaided thresholds of at least 80 dB HL at two or more of 500, 1000, 2000, 3000 and 4000 Hz in both ears. For adults, adequate acoustic-aid benefit is an Arthur Boothroyd phoneme score of at least 50% at 70 dBA; a lower score indicates inadequate benefit within this definition.
04Treatment approachPreparation, options, escalation and aftercare.
01Conventional hearing-aid rehabilitationFit the device and support effective useFirst stepThe adult has aidable loss affecting communication or other important listening activities.
  1. 1Discuss the available approaches, offer bilateral aids when both ears are aidable and agree realistic goals for the fitting.
  2. 2Demonstrate insertion, controls, cleaning, batteries or charging, telephone use and relevant features such as directional microphones or noise reduction.
  3. 3Arrange the six-to-12-week review and an earlier contact route for problems, adding communication strategies and assistive devices where they address remaining needs.
02A bone-conduction or other specialist deviceTest the benefit and prepare for long-term careConventional canal-based amplification is unsuitable or inadequate for the particular hearing problem.
  1. 1Refer for specialist assessment of the available non-surgical and implant options, with a suitable trial and discussion of expected listening benefit.
  2. 2If implantation is chosen, document the surgical plan, postoperative wound care and when the processor may first be connected; early unauthorised fitting can damage the fixture.
  3. 3Teach model-specific care, skin checks, retention and water precautions, and provide the implant identification details needed for future imaging and procedures.
03Cochlear-implant referralApply the criteria while preserving individual accessSevere-to-profound bilateral hearing impairment gives insufficient benefit from acoustic aids.
  1. 1Refer for multidisciplinary assessment, including a valid acoustic hearing-aid trial of at least three months unless a trial is contraindicated or inappropriate.
  2. 2Use age-appropriate measures: the adult Arthur Boothroyd criterion differs from the child's assessment of speech, language and listening development. Adapt testing for disability or language needs rather than treating an inaccessible test as evidence of poor auditory benefit.
  3. 3Discuss unilateral implantation or the defined bilateral options, the operation, programming and rehabilitation. If implantation is declined or unsuitable, maintain audiological care and allow reassessment when circumstances change.
05Complications, monitoring and follow-upAdverse effects, response and longer-term review.
  • At hearing-aid review, assess benefit against agreed goals, comfort, settings, insertion, cleaning and battery or charging management.
  • For implanted devices, check wound healing and follow the team's activation and programming appointments rather than connecting a trial processor early.
  • Ask users or support people to look for redness, an indentation beneath a magnet, debris or discharge around an abutment, and seek specialist advice promptly if these appear.
  • Review ongoing communication and safety needs, including access to alarms and important instructions when a processor is removed or unavailable.
  • Keep device identification and contact details accessible, and reassess aid or implant candidacy when hearing, speech understanding or practical needs change.
06Special situationsVariants, exceptions and circumstances that change the usual approach.

Bilateral implantation has defined indications

TA566 supports simultaneous bilateral cochlear implants as an option for children and for adults who are blind or have other disabilities increasing reliance on auditory cues for spatial awareness, provided the other criteria are met. Sequential bilateral implantation is not generally recommended by that appraisal; a specified pre-existing unilateral-implant exception requires individual assessment.

Sound routing is not two functioning cochleae

A CROS arrangement captures sound on the poorly hearing side and delivers it to the better ear. Bone-conduction routing in single-sided deafness has a related aim. These strategies can improve awareness from that side, but their mechanism should not be described as restoring separate sensory input from the deaf cochlea.

MRI precautions are device specific

The radiology and implant teams must identify the exact internal device and its permitted scanning conditions. Field strength, magnet management and other precautions vary; some older devices are unsuitable for MRI. External processors must be removed before entering the scan room, but this step alone is not clearance for scanning.

Magnet strength is a clinical adjustment

A stronger magnet may improve retention but can compress and damage the skin. Redness or a persistent indentation calls for prompt implant-team advice rather than simply enduring discomfort. Percutaneous devices have different care needs around the abutment, including cleaning and attention to loosening or discharge.

Battery safety includes used cells

Keep both spare and used batteries inaccessible to children and anyone at risk of swallowing or inserting them. Ask audiology about secure compartments when appropriate. Small hearing-device batteries still pose serious harm; a suspected incident needs emergency assessment even if the person appears well.

07Common pitfallsFrequent interpretation and management errors.
  1. 01

    Treating a hearing-aid fitting as complete without checking practical use and functional benefit.

  2. 02

    Assuming a cochlear implant is indicated by severe thresholds alone without assessing aided performance and multidisciplinary suitability.

  3. 03

    Using an adult speech-test cutoff to judge a child or someone for whom the test language is inaccessible.

  4. 04

    Describing a routing device as restoring independent hearing in a non-functioning cochlea.

  5. 05

    Assuming all implants are MRI safe after the external processor has been removed.

Practice

Two practice questions

Question 1 of 20 correct
Ear, nose and throatOriginal SBA

Identifying the TA566 threshold and benefit pattern

Five adults complete a valid three-month acoustic hearing-aid trial and reliable testing in an appropriate language. Which result meets both the audiometric severity and inadequate-aided-benefit definitions in NICE TA566 for considering cochlear implantation through multidisciplinary assessment?

Sources and review status7 sources · checked 7 Sept 2026 · clinical review pending
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 7 Sept 2026; clinical approval remains outstanding.

Authoring stateComplete draftClinical stateAwaiting reviewJurisdictionUnited Kingdom