Object localization in cluttered acoustical environments

In nature, sounds from objects of interest arrive at the ears accompanied by sound waves from other actively emitting objects and by reflections off of nearby surfaces. Despite the fact that all of these waveforms sum at the eardrums, humans with normal hearing effortlessly segregate one sound source from another. Our laboratory is investigating the neural basis of this perceptual feat, often called the "cocktail party effect", using the barn owl as an animal model. The barn owl, renowned for its ability to localize sounds and its spatiotopic representation of auditory space, is an established model for spatial hearing. Here, we briefly review the neural basis of sound-localization of a single sound source in an anechoic environment and then generalize the ideas developed therein to cases in which there are multiple, concomitant sound sources and acoustical reflection.