Age-related central gain compensation for reduced auditory nerve output for people with normal audiograms, with and without tinnitus

• Main Authors: Peter T. Johannesen, Enrique A. Lopez-Poveda
• Format: Article
• Language: English
• Published: Elsevier 2021-06-01
• Series: iScience
• Subjects: biological sciences; neuroscience; sensory neuroscience
• Online Access: http://www.sciencedirect.com/science/article/pii/S258900422100626X

Summary: Central gain compensation for reduced auditory nerve output has been hypothesized as a mechanism for tinnitus with a normal audiogram. Here, we investigate if gain compensation occurs with aging. For 94 people (aged 12–68 years, 64 women, 7 tinnitus) with normal or close-to-normal audiograms, the amplitude of wave I of the auditory brainstem response decreased with increasing age but was not correlated with wave V amplitude after accounting for age-related subclinical hearing loss and cochlear damage, a result indicative of age-related gain compensation. The correlations between age and wave I/III or III/V amplitude ratios suggested that compensation occurs at the wave III generator site. For each one of the seven participants with non-pulsatile tinnitus, the amplitude of wave I, wave V, and the wave I/V amplitude ratio were well within the confidence limits of the non-tinnitus participants. We conclude that increased central gain occurs with aging and is not specific to tinnitus.