Older adults show reduced cochlear two-tone suppression

Evidence

Estimates of high-side and low-side suppression were significantly smaller for older adults than for younger adults. Most previous studies of aging effects on suppression have found decreased or absent suppression for older adults (Sommers and Gehr 1998 , 2010 ; Dubno and Ahlstrom 2001a , b ). In the present study, suppressor levels were chosen to not produce forward masking and to result in the greatest measure of suppression. Also, with the long combined masker, some older adults did not show high-side suppression, and some did not show low-side suppression. By using short combined maskers with individually-selected suppressor levels, accurate measurements of suppression can be achieved. — Dijk, Pim van, Physiology, Psychoacoustics and…, 961

The present study found strong evidence for age-related decreases in both high-side and low-side two-tone suppression and in estimates of cochlear gain. These findings are consistent with a decreasing endocochlear potential that occurs with increasing age. The results also support the hypothesis that that suppression estimates may be underestimated when measured with long combined maskers, which would be consistent with a reduction in suppression due to the MOCR. — Dijk, Pim van, Physiology, Psychoacoustics and…, 964

Categorization

• XREF: Connects to general reading on age-related hearing loss and MOCR mechanisms; ties cochlear gain loss to endocochlear potential decline.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 961; Dijk, Pim van, Physiology, Psychoacoustics and…, 964