The perceptual organization of complex sounds by birds

Birds have proven to be ideal models for the perceptual organization of complex sounds because, like humans, they produce, learn, and use complex acoustic signals for communication. Although conducted in laboratory settings, measures of auditory abilities in birds are usually designed to parallel the acoustic problems faced in their natural habitats, including the location of conspecifics, discrimination among potential mates, prey localization, predator avoidance, and territorial defense. As a result, there is probably more known about hearing in birds under both natural and laboratory conditions than in any other nonhuman organism. Behavioral and/or physiological experiments on complex sound perception in birds have revealed that they exhibit serial pattern perception, can discriminate frequency changes in tones embedded within tonal patterns regardless of stimulus uncertainty conditions, segregate signals into auditory streams, and exhibit comodulation masking release. In addition, binaural experiments have revealed that birds exhibit both the cocktail party effect and the precedence effect. Taken together, these results suggest that, like humans, auditory scene analysis plays a general role in auditory perception in birds and probably other animals that must parse the world into auditory objects. [Work supported by NIH DC006124.]