Seminar Speaker – Daniel Tollin, Ph.D

Children experiencing asymmetrical hearing early in life, typically due to conductive hearing loss (CHL) associated with ear infection, often display reduced behavioral auditory spatial acuity that persists long after hearing is restored. We hypothesized that persistent CHL disrupts the experience-dependent fine-tuning of binaural hearing necessary in the developing auditory system to support normal behavioral spatial acuity. Animals reared with chronic unilateral CHL during development caused the brain to generate a less precise representation of auditory space - that is, both the spatial acuity of single neurons and behavioral sound location acuity were ~threefold worse than control, as if the sense of auditory space had been blurred. The results suggest that experiencing even temporary hearing loss during development can persistently alter the normal maturation of brainstem circuits that are necessary to support good spatial acuity in adulthood.