Of ~35,000 neurons present in each cochlea at birth, 1000-2000 are lost per decade due to normal aging and exposure to loud sound. Further neurons may be lost from overexposure to loud sounds, but the consequences of cochlear neurodegeneration are not well understood. Our lab uses behavioral operant conditioning experiments in an avian model species to characterize the effects of cochlear neurodegeneration on behavioral sensitivity to complex sounds. We also use neural recordings from the inferior colliculus of the midbrain to identify the changes in central processing that underlie deficits in auditory perception.