Blame the Brain, Not the Ears, for Age-Related Hearing Loss

Age-related hearing difficulties may have less to do with the ears themselves and more to do with how the brain processes sound. According to reporting by Co.Exist, recent research published in the Journal of Neurophysiology suggests that the true challenge lies in neural sound processing rather than in the mechanical function of the ear.

The study, conducted by researchers at University of Maryland, College Park, examined how aging affects the brain’s ability to interpret competing sounds. Researchers focused on two key brain regions involved in hearing: the midbrain, which plays a role in auditory, visual, and motor processing, and the cortex, which is associated with higher-level functions such as language and cognition.

Seventeen younger adults and fifteen older adults with no signs of dementia participated in the study. Each participant listened to an audiobook while a second narrated audiobook played simultaneously in the background. This setup was designed to replicate a common real-world challenge—trying to follow one conversation amid competing voices.

The findings revealed that older adults’ midbrains responded less robustly to sound compared to those of younger participants. As a result, auditory signals were encoded less effectively, and speech processing took longer—particularly in situations involving multiple speakers. In short, the aging brain struggled more to isolate a single voice from background noise.

Interestingly, the cortex of older adults showed the opposite pattern. It reconstructed the loudness (amplitude) of the speech signal with greater accuracy than younger adults’ brains. However, this heightened cortical response appears to reflect inefficiency rather than improvement. As noted in the study’s abstract, the exaggerated cortical activity suggests “an age-related over (or inefficient) use of cognitive resources,” which may explain why older adults often find it difficult to focus on speech while ignoring background noise.

These findings help explain why speaking louder rarely improves communication with older listeners. The issue is not volume, but clarity. Reducing background noise and speaking in quieter environments is far more effective than raising one’s voice.

Sources:
– Journal of Neurophysiology, age-related auditory processing study
– Co.Exist, summary of research findings