Getting a hearing aid when hearing declines — the reason is to hear better now, not to prevent dementia

The claim that “wearing a hearing aid prevents dementia” currently lacks solid evidence. A three‑year trial involving nearly a thousand participants found no overall difference between groups. Only among people already at higher risk of cognitive decline did a modest benefit appear. Thus, the main reason to get a hearing aid is to hear clearly now — to talk with others and hear traffic while crossing the street — not to protect the brain decades later.

Hearing aids cost several thousand to tens of thousands of yuan; most must be paid for out of pocket. Fitting requires professional testing and multiple follow‑up adjustments.

The ACHIEVE trial took place in four U.S. communities and enrolled 977 individuals aged 70–84 with untreated hearing loss but no obvious cognitive impairment. Participants were randomly assigned to either hearing intervention (counseling and hearing aid fitting) or health‑education control, with follow‑up every six months. The primary endpoint was change in overall cognitive scores over three years. In the combined analysis of both participant cohorts, there was no significant difference: the intervention group showed a change of −0.200 (95% CI −0.256 to −0.144) versus −0.202 (95% CI −0.258 to −0.145) in the control group; the difference was 0.002 (95% CI −0.077 to 0.081, P = 0.96). A pre‑specified sensitivity analysis revealed a statistically significant interaction (P = 0.010) between the two cohorts. The second cohort comprised older participants with more risk factors for cognitive decline and lower baseline cognitive scores. Researchers concluded that hearing intervention may modestly slow cognitive decline over three years in high‑risk individuals but not in those at lower risk. No serious adverse events attributable to the intervention were reported.

Controversy: The oft‑quoted claim that “hearing aids cut cognitive decline by nearly half” stems from a subgroup analysis of this trial, not its primary result, which showed no overall difference. This note is included to separate the practical benefit of hearing aids from the unproven dementia‑prevention claim. Students with hearing impairments may be exempt from foreign‑language listening tests in college entrance exams; see item 13 (reasonable accommodations) in this section. Drivers with hearing loss should wear hearing aids; see item 15 (C5) in this section.

Lin FR, Pike JR, Albert MS, et al.; ACHIEVE Collaborative Research Group (2023). Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a multicentre, randomised controlled trial. Lancet, 402(10404):786-797. https://doi.org/10.1016/S0140-6736(23)01406-X