Perceptual organization of complex auditory sequences: Effect of number ofsimultaneous subsequences and frequency separation

Previous findings on streaming are generalized to sequences composed of mor e than 2 subsequences. A new paradigm identified whether listeners perceive complex sequences as a single unit (integrative listening) or segregate th em into 2 (or more) perceptual units (stream segregation). Listeners heard 2 complex sequences, each composed of 1, 2, 3, or 4 subsequences. Their tas k was to detect a temporal irregularity within 1 subsequence. In Experiment I, the smallest frequency separation under which listeners were able to fo cus on 1 subsequence was unaffected by the number of co-occurring subsequen ces; nonfocused sounds were nor perceptually organized into streams. In Exp eriment 2, detection improved progressively, not abruptly, as the frequency separation between subsequences increased from 0.25 to 6 auditory filters. The authors propose a model of perceptual organization of complex auditory sequences.