Enhanced pitch perception in early blind individuals and musicians is due to reduced internal noise

Although it is commonly assumed that early blind individuals have enhanced pitch perception, the literature to date has been contradictory. We measured performance on two tasks known to recruit early versus late stages of auditory frequency tuning in early blind and sighted human adults of both sexes with matched years of musical training. The two groups showed equivalent performance on a tone detection in notched-noise task that assesses cochlear frequency selectivity. In contrast, early blind individuals showed enhanced performance in a pitch discrimination task thought to be mediated by cortical mechanisms. Computational modeling revealed that this enhancement was best explained by reduced internal noise rather than narrower frequency tuning, with both blindness and years of musical training predicting a reduction in internal noise. These findings identify internal noise as a key factor in experience-driven auditory plasticity as a result of both musical experience and early blindness.Significance Statement For centuries, early blindness has been associated with superior auditory abilities. Here we find that the enhanced pitch perception in early blind individuals is best explained by reduced internal noise at higher levels of auditory processing, rather than sharper frequency tuning. Years of musical training similarly resulted in lower internal noise, suggesting a shared mechanism through which experience improves auditory perception. These findings identify internal noise reduction as a key component of experience-dependent auditory plasticity.