Events

Perception arises from the successful communication between a "transmitter" (e.g., sensory end organs such as the retina or cochlea) and a "receiver" (e.g., the brain). As with any communication system, disordered perception can reflect a breakdown of the transmitter, the receiver, or some combination of the two. However, contemporary approaches to understand the biological basis of hearing loss (as well as hearing restoration) are almost entirely focused on the status of the peripheral transmitter. Comparatively less is known about how higher levels of the auditory CNS compensate for a loss of peripheral input and whether the plasticity of these circuits can be harnessed and directed through immersive auditory training protocols to promote further gain of function. In this talk, I will present two new lines of research that explore the link between plasticity and improved hearing. The first describes a remarkable reorganization in the midbrain and cortex of adult mice after near-complete denervation that restores sensitivity to sound properties encoded by overall spike rate, but offers little benefit to sound properties encoded by precise action potential timing. The second topic describes the effects of training mice and humans to forage in virtual 2-D soundscapes in search of auditory targets associated with a barely perceptible tone in noise. In mice, task-related improvements are associated with the emergence of noise resistant cortical unit responses that are tuned to low intensity sounds. In man, mastery of this simple task generalizes to an improved ability to perceive speech in noisy backgrounds. These findings highlight the involvement of higher auditory CNS areas in enhancing the perceptual salience of degraded signals inherited from the auditory periphery.