Spring 2016
Seminars are held at 11:30AM in Cullimore Hall, Room 611, unless noted otherwise. For questions about the seminar schedule, please contact Casey Diekman.
Date: April 26, 2016
Speaker: Catherine Carr
Department of Chemical and Biomolecular Engineering,
University of Pennsylvania
Title: "Listening with Two Ears"
Abstract:
Listening with two ears tells us where sounds are coming from, and provides an amazing resistance to background noise. My talk will focus on nocturnal predators who are champion listeners, barn owls, alligators and geckos. Like us, their ability to localize sound depends on mechanisms that enhance directionality, like detection of interaural time differences (ITD). Birds, crocodilians, turtles and lizards have homologous brainstem circuits for detection of ITDs. In birds and crocodilians these circuits form maps of ITD composed of delay lines and coincidence detectors. Lizards, however, have coupled ears, and all lizard auditory nerve fibers have strongly directional responses, i.e. peripheral specializations remove the need for central computation of ITD. Thus the processing of sound direction in the bird, alligator and lizard CNS is different, but all three groups have mechanisms for enhancing sound source directionality. These different strategies can be used for design and improvement of hearing aids and cochlear implants.