The barn owl is a nocturnal hunter and a good model for how we localize sound and process temporal information in general. When sound comes from one side of the body, it reaches one ear before the other, and our brain translates these interaural time differences (ITDs) into location in space in the brainstem. Detection of ITDs depends upon two mechanisms of general significance to neurobiology, delay lines and coincidence detection. Incoming axons form delay lines to create maps of ITD in the nucleus laminaris. Their postsynaptic targets act as coincidence detectors and fire maximally when the interaural time difference is equal but opposite to the delay imposed by the afferent axons. Current research is focused on the assembly of the map of sound localization during development and on how such circuits evolve. We are also looking at ITD coding in some of the birds' relatives, including alligators, lizards and turtles. All projects develop from initial behavioral observations into systems, cellular and molecular levels of analysis.