Age-related hearing loss (presbycusis) affects one-third of the world’s population. One hallmark of presbycusis is difficulty hearing in noisy environments, like making out somebody’s voice in a crowded restaurant or bar.

A lot of focus has been placed on age-related changes to the inner ear. Less is known about the age-related changes in the brain that affect auditory processing. A few years ago we started to study how age changes the processing of sound information in the auditory cortex and what the underlying circuit changes are. The long-term goal is to figure out if we can prevent or reverse such changes and preserve normal hearing.

Age-related changes in auditory cortex function

So far our work in mice has shown that auditory cortex contains distinct subpopulations of excitatory neurons that preferentially encode different stimulus features and that aging selectively reduces certain subpopulations. We also found that aging increases correlated activity between neurons and thereby causes deficits in sound encoding (Shilling-Scrivo et al. 2021). We then trained mice to detect tones in noise and found that aging reduces the ability to suppress their responses to background noise. This excess activity also leads to increased correlations between neurons, reducing stimulus information in the auditory cortex (Shilling-Scrivo et al. 2022, JHU news). 

Age-related circuit changes in the auditory cortex

We then investigated the underlying circuit changes in a mouse model of presbycusis (C57Bl/6 mice) and found changes in specific excitatory and inhibitory cortical circuits (Xue et al. 2023). However, changes in the auditory cortex also occur in a sex-specific way in aging CBA mice that do not suffer from peripheral hair cell loss (Xu et al. 2025). Thus, besides peripheral hair cell loss, aging also has distinct effects on the central nervous system, especially the cortex, and that this might differ between males and females.

Auditory training can prevent age-related functional changes

While we cannot get younger, it might be possible to slow age-related changes, especially those occurring in the cortex. Because of the marked plasticity of the brain, we investigated if engaging in a low-effort auditory task can prevent some of the age-related changes in hearing. We trained mice in automated training chambers for >6 months and found that these animals retained many aspects of youthful hearing. Thus, being engaged in auditory tasks seems to forestall many changes with aging (Mittelstadt et al. 2024). Moreover, our experiments also show that temporary visual deprivation can prevent some of the age-related hearing loss (Jendrichovsky et al. 2025). Thus, together our results suggest that long duration, low-effort auditory training, possibly coupled with visual deprivation, might be a promising easy-to-implement therapeutic strategy to prevent the age-related central hearing loss.

Clinical Relevance

Age-related hearing loss is a massive problem. Finding solutions to prevent or slow down these changes is critical for human health. Since hearing loss is linked with dementia (JHU news, JAMA, JAMA), such training might also be promising to reduce the incidence of dementia by preserving hearing as we age.

Key Publications

J. Mittelstadt, K. Shilling-Scrivo, P.O. Kanold, “Aging in the Primary Auditory Cortex”,  JARO 2025

Z. Xu, B. Xue, J.P-Y Kao, P.O. Kanold , “Sex-specific age-related changes in excitatory and inhibitory intracortical circuits in mouse primary auditory cortex”, eNeuro 2025

P. Jendrichovsky, H-K Lee, P.O. Kanold, “Brief periods of visual deprivation in adults increase performance on auditory tasks”, iScience 2024

J. Mittelstadt, K. Shilling-Scrivo, P. O. Kanold, “Long-term training alters response dynamics in the aging auditory cortex”, Hearing Research, 2024

B. Xue, X. Meng, J.P-Y Kao, P.O. Kanold, “Age-related changes in excitatory and inhibitory intra-cortical circuits in auditory cortex of C57Bl/6 mice” Hearing Research 2023

K. Shilling-Scrivo, J. Mittelstadt, P.O. Kanold, “Decreased modulation of population correlations in auditory cortex is associated with decreased auditory detection performance in old mice”, J. Neuroscience 2022

K. Shilling-Scrivo*, J. Mittelstadt*, P.O. Kanold, “Altered response dynamics and increased population correlation to tonal stimuli embedded in noise in aging auditory cortex”, J. Neuroscience 2021