Neural Underpinnings of Temporal Processing in the Aging Auditory System

Individuals with typical audiometric sensitivity exhibit varying speech perception abilities in noisy environments, which may decline with age. Temporal processing plays a pivotal role in speech perception, especially in challenging listening conditions. Auditory decline due to aging involves both peripheral pathology and central auditory system changes, impacting temporal processing. To delineate the contributions of these changes, measurements of within- and across-channel temporal processing were conducted in a wide age range of normal-hearing individuals. Robust perception of within-channel temporal cues requires precise coding at both peripheral and central auditory pathway levels, while cross-channel processing relies on central mechanisms. Comprehensive data collection involved behavioral and electrophysiological measures, revealing age-related increases in behavioral thresholds, less robust cortical responses to gaps and temporal-coherence changes, and declining SPIN performance. Cross-channel measures proved to be more predictive of speech perception outcomes, emphasizing the significance of central auditory changes in age-related perceptual deficits.

A mini-EEG cap to record cortical EEG auditory responses to gaps in chinchillas using a new sedation protocol was validated. This advancement enhances translational potential and paves the way for exploring cortical auditory processing using complex stimuli in animal models. By facilitating simultaneous exploration of both subcortical and cortical consequences of auditory system pathologies, this development contributes to a more comprehensive understanding of auditory processes across species.