What are the best fitting practices for hearing aids?

Best Fitting Practices for Hearing Aids

Hearing aid fitting should be based on a prescriptive procedure that incorporates individual real-ear measures accounting for each patient's ear-canal acoustics and hearing loss, with verification that amplified speech is comfortably above sensory threshold but below discomfort level across the speech frequency range. 1

Core Fitting Principles

Goal of Amplification

• The primary objective is to provide maximum access to all acoustic features of speech within an intensity range that is safe and comfortable 1
• Amplified speech must be comfortably above the patient's sensory threshold but below the level of discomfort across the entire speech frequency range for both ears 1

Essential Pre-Fitting Assessment

• Hearing aid fitting proceeds optimally when results of physiologic audiological assessment including diagnostic ABR, OAE, and tympanometry are in accord with medical examination 1
• For infants below developmental age of 6 months, hearing aid selection must be based on physiologic measures alone 1
• Behavioral threshold assessment with visual reinforcement audiometry should be obtained as soon as possible to cross-check and augment physiologic findings 1
• A comprehensive audiologic evaluation must include pure-tone testing, word recognition testing, speech-in-noise testing, and loudness discomfort level measures 2

Verification and Validation Protocol

Real-Ear Measurements (Critical)

• Amplification-device selection, fitting, and verification must be based on a prescriptive procedure that incorporates individual real-ear measures 1
• Real-ear (microphone verification) measures determine if hearing aids are meeting actual prescriptive targets and can identify under-amplification as a cause of patient dissatisfaction 1

Validation Requirements

• Validation of amplification benefits, particularly for speech perception, should be examined in both the clinical setting and the child's typical listening environments 1
• Self-assessment measurement tools such as the Hearing Handicap Inventory for the Elderly (HHIE) or Hearing Handicap Inventory for Adults (HHIA) should be used to determine impact on quality of life 1

Ongoing Monitoring and Adjustment

Regular Follow-Up Schedule

• Monitoring of amplification requires ongoing audiological assessment along with electroacoustic, real-ear, and functional checks of the hearing instruments 1
• Periodic evaluations of hearing to monitor stability and evaluation of amplification/assistive listening devices should occur at least annually for adults and children aged >5 years 1
• More frequent monitoring may be warranted in individuals with fluctuating hearing loss 1
• For infants and young children, developmental monitoring should occur at regular 6-month intervals 1

Refinement Over Time

• As hearing loss becomes more specifically defined through audiological assessments and as the child's ear-canal acoustics change with growth, refinement of individual prescriptive hearing-aid gain and output targets is necessary 1
• Monitoring must include periodic validation of communication, social-emotional, and cognitive development and, later, academic performance to ensure progress is commensurate with the child's abilities 1

Timing Considerations

Prompt Fitting

• If the family chooses personal amplification, hearing-aid selection and fitting should occur within 1 month of initial confirmation of hearing loss, even when additional audiological assessment is ongoing 1
• Delay between confirmation of hearing loss and fitting of an amplification device should be minimized 1
• Audiological habilitation services should be provided by an audiologist who is experienced with these procedures 1

Technology Level Considerations

Evidence on Premium vs. Basic Technology

• Research demonstrates no statistically significant or clinically important differences in speech understanding improvement or quality of life between premium-level and basic-level hearing aids 3
• It should not be assumed that more costly hearing aids always produce better outcomes 3
• Regardless of technology level, comprehensive best-practice fitting protocols should be followed to optimize results for every patient 3

Special Considerations

Complementary Technology

• Frequency modulation (FM) systems or cochlear implants may be recommended as primary and/or secondary listening devices depending on the degree of hearing loss, goals of auditory habilitation, acoustic environments, and family's informed choices 1

Cochlear Implant Referral Criteria

• Patients should be referred for cochlear implant evaluation when they have appropriately fit amplification and persistent hearing difficulty with poor speech understanding 1
• The "60/60" guideline (pure tone average thresholds ≥60 dB and word recognition ≤60%) has 96% sensitivity for identifying cochlear implant candidates 1, 4

Sound Tolerance Issues

• Problems related to loudness of sounds and reduced sound tolerance can adversely impact adaptation to amplification and quality of life 5
• A structured assessment tool should be used to evaluate reduced sound tolerance and its impact on hearing aid use 5

Common Pitfalls to Avoid

• Do not rely on patient self-report alone for determining adequacy of hearing aid fitting, as patients cannot accurately differentiate degree of hearing loss or identify losses requiring intervention 1
• Avoid under-amplification by confirming prescriptive targets are met through real-ear measurements 1
• Do not assume infants and young children with well-fit amplification devices will automatically develop auditory skills—ongoing validation is essential 1