Auditory Perception

Hearing loss is defined as an impaired ability to hear sounds at thresholds considered to be normal. Projections based on audiometric data from the National Health and Nutrition Examination Survey estimate that by 2030, approximately 55 million US adults will have hearing loss, including 35 million with mild loss (25-40 dB) and nearly 20 million with moderate or greater loss (>40 dB).1 The most common cause of hearing loss among hearing aid users is bilateral sensorineural hearing loss due to cochlear hair cell or auditory nerve degeneration. Functional effects of hearing loss differ with severity. Mild hearing loss may affect the ability to understand speech in noisy environments; moderate or greater hearing loss affects the ability to have individual conversations in a quiet room.

Untreated hearing loss is associated with social isolation that can reduce quality of life.2 A meta-analysis of 5 randomized trials (825 adults with mild to moderate hearing loss) that compared those not receiving hearing aids with those who received hearing aids that amplified sounds via air conduction had improved ability to discriminate sound and speech and hearing-related quality of life based on Hearing Handicap Inventory for the Elderly,2 which quantifies self-perceived functional and emotional hearing handicap (such as negative feelings and psychological distress from communication problems). The Hearing Handicap Inventory for the Elderly scores (lower scores indicate less handicap; scale, 0-100) improved by −26.5 (95% CI, −42.2 to −10.8) points with hearing aids, exceeding the minimal clinically important difference of 18.7 points.2

Amplification with hearing aids is the primary treatment for hearing loss, but use is limited. Traditional Medicare does not cover hearing aids, and coverage for associated services remains limited. In a nationally representative cohort using data from the National Health and Aging Trends Study, hearing aid use among US adults aged 71 years and older with hearing loss was 29.2% in 2021, including 14.4% among those with mild loss and 45.3% among those with moderate hearing loss.3 Although reasons for nonuse were not directly assessed, lower-income individuals, along with those who have milder degrees of hearing loss, are less likely to use hearing aids.3 Until recently, hearing aids in the US could only be obtained through licensed hearing care professionals such as audiologists. However, since October 2022, the US Food and Drug Administration has allowed adults to buy hearing aid devices without a medical examination, prescription, or professional fitting. This regulatory change has enabled over-the-counter (OTC) direct-to-consumer hearing aids, with potential to broaden access.