Perceptual asymetries in audition.

Visual feature extraction has been investigated using search experiments. Targets that contain a feature not present in the distractors are easier to detect than if they do not, leading to search asymmetries. If sounds are decomposed into features in the auditory system, there might be asymmetries in analogous tasks. Six experiments investigating this are described. Strong asymmetries were identified, with frequency-modulated targets easier to detect among pure-tone distractors than vice versa and longer sounds easier to select from short distractors than the reverse. It is demonstrated that this asymmetry is not a result of peripheral limitations. In contrast, no asymmetries were observed between high- and lowfrequency tones or between short 3-tone sequences differing only in their temporal structure. The results are discussed with reference to models of perceptual grouping and attention, the applicability of analogies between vision and audition, and possible physiological correlates. The paradigm provides a new way in which to investigate auditory feature extraction.