Behavioral and Physiological Consequences of Auditory Nerve Loss
This project in the Henry lab investigates the link between cochlear synaptopathy and hidden hearing loss. Of ~30,000 auditory-nerve fibers innervating each human cochlea at birth, 1000-2000 are lost per decade of life due to normal aging and exposure to loud sounds. Auditory-nerve loss, called cochlear synaptopathy, is undetectable with standard clinical tools because it does not elevate the threshold for pure-tone detection in quiet (i.e., the audiogram). Rather, cochlear synaptopathy is widely hypothesized to cause impaired complex-sound perception in noise, known as "hidden hearing loss." The Henry lab uses behavioral, neurophysiological, and histological experiments in an animal model to test the hypothesis that cochlear synaptopathy causes hidden hearing loss and to identify underlying changes in auditory processing that contribute to perceptual differences.