Abstract

Untreated hearing loss has been recognized as a potentially modifiable risk factor for cognitive decline. Research demonstrates that many "at-risk" adults with untreated hearing loss experience earlier onset and faster cognitive deterioration ("at-risk" as used here includes people with additional risk factors such as older adults, people with greater hearing loss, people with cardiovascular disease, diabetes, and/or polypharmacy issues, etc). Auditory decline begins decades before it is detected by conventional hearing tests. Sub-clinical changes such as cochlear synaptopathy, speech-in-noise problems, and extended high-frequency loss can disrupt auditory–cognitive processing even when conventional hearing thresholds from 250 to 8000 Hz appear normal. Early symptoms like tinnitus and difficulty understanding speech in noise may signal underlying neural vulnerability. Sub-clinical (not visible on a conventional hearing test) auditory deficits may increase cognitive load, as the brain must work harder to process degraded sound. Over time, this sustained effort may reduce neural efficiency and may contribute to cognitive maladaptation and may accelerate atrophy in brain regions involved in memory and executive function. Social isolation, anxiety, depression, and reduced communication are common consequences of untreated hearing loss, each of which may compound cognitive risk. Emerging evidence suggests that hearing loss is not only a marker but may also be a mechanism of cognitive decline. Degradation of speech-in-noise performance and the presence of tinnitus are associated with increased dementia risk and may serve as early biomarkers. Intervention studies indicate that hearing aids may slow cognitive decline in at-risk patients, with trials like ACHIEVE showing nearly a 50% reduction in cognitive decline over three years. Overall, early detection via comprehensive auditory testing (not hearing screenings) is critical. Diagnosing and treating hearing loss promptly (mid-life) may preserve cognitive function, may reduce dementia risk, and may support long-term brain health before the negative consequences of long-term untreated hearing loss appear.

Keywords

Auditory