Effects of Age on the Adult Peripheral Auditory System
Abstract
Age-related changes in the auditory nerve and brainstem function were studied using electrocochleography (ECochG) and auditory brainstem responses (ABR) in young and old adult age groups. Isolating the effects of aging from lifetime ototoxic exposures such as noise is challenging. For this reason, only participants with normal audiograms were studied. Extended high frequency thresholds and distortion product otoacoustic emissions (DPOAEs) were also measured. Results reveal significant age-related differences. Older adults exhibit longer ECochG AP and ABR wave I and V latencies compared to younger adults, while the amplitude of these components, and the ECochG SP latency and amplitudes were unaffected by age. Additionally, elevated extended high frequency thresholds and lower DPOAE levels were found in older adults. Age-related changes in auditory nerve and brainstem function in adults with normal clinical hearing may impact speech understanding, particularly in noisy environments.