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Presbyacusis, one of the most common ailments of the elderly, is often treated with hearing aids, which serve to reintroduce some or all of those sounds lost to peripheral hearing loss. However, little is known about the underlying changes to the ear and brain as a result of such experience with sound late in life. The present study attempts to model this process by rearing aged CBA mice in an augmented acoustic environment (AAE).

The effects of exposure to an augmented acoustic environment (AAE) on auditory function were evaluated in mouse strains that exhibit high-frequency hearing loss beginning during young adulthood (the C57BL/6J strain [C57]) or around the time of weaning/adolescence (the DBA/2J strain [DBA]). Beginning at age 25 days, mice were exposed 12 h every night to a 70 dB SPL broad-band noise AAE. The AAE was maintained until age 14 months in C57 mice and 9 months in DBA mice. Control mice were age-matched and maintained under normal vivarium acoustic conditions. The auditory brainstem response (ABR), acoustic startle response amplitude, and prepulse inhibition (PPI) were used to assess the auditory system. Exposure to the AAE resulted in improved auditory performance in both strains (better PPI, lower ABR thresholds, bigger startle amplitudes).