Noise-induced hearing loss delays auditory learning and reduces the influence of acoustic evidence on choice

Noise-induced hearing loss (NIHL) impairs auditory sensitivity, but its impact on learning sound-guided decisions is not well understood. Researchers trained Mongolian gerbils with normal hearing and those with permanent NIHL to distinguish 4- or 12-Hz amplitude-modulated broadband noise in a forced-choice task. Both groups were exposed to stimuli at equivalent loudness levels.

NIHL-affected gerbils needed about two and a half times more training sessions and trials to reach the learning threshold compared to normal-hearing animals. This learning delay was not due to reduced task engagement, response speed, or changes in auditory brainstem responses. Video tracking showed that spatial focus in both groups improved with training, while movement paths of the normal-hearing gerbils became more consistent.

Logistic regression models indicated that both groups' reliance on the acoustic stimulus increased with training; however, NIHL animals consistently showed lower influence of the task-relevant sound during choice-making. The findings suggest that NIHL delays auditory learning by reducing the role of acoustic evidence in decision-making, implying that hearing loss can influence how sensory experiences contribute to acquiring new behaviors.