[Frontiers in Bioscience 13, 148-169, January 1, 2008]

The auditory organization of complex sounds

Valter Ciocca

School of Audiology and Speech Sciences, Faculty of Medicine, The University of British Columbia, 5804 Fairview Avenue, Vancouver, B.C. V6T 1Z3, Canada

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. The nature of auditory grouping processes
3.1. General-purpose and schema-based grouping processes
3.2. General-purpose grouping processes
3.2.1. Sequential grouping
3.2.2. Common onset
3.2.3. Spectral regularity and harmonicity
3.2.4. Spatial cues
3.2.5. Coherent modulation
3.3. Schema-based grouping processes
3.3.1. Attribute-specific schemas
3.3.2. Categorical schemas
4. The auditory grouping of frequency components into the perceptual attributes of complex sounds
4.1. Pitch schema
4.2. Loudness schema
4.3. Timbre schema
5.The effects of auditory grouping on the recognition of complex sounds
5.1. Speech schema
5.1.1. Sequential grouping
5.1.2. Common onset
5.1.3. Spatial cues
5.1.4. Common modulation
5.1.5. Harmonicity
5.2. Nonspeech schemas
5.3. The interaction between auditory organization processes and categorical schemas
6. The auditory organization of auditory streams and simultaneous auditory events
6.1. The sequential organization of auditory streams
6.1.1. Nonspeech sounds
6.1.2. Speech sounds
6.2. Auditory grouping of simultaneous auditory events
6.2.1. Nonspeech sounds
6.2.2. Speech sounds
7. Final discussion
8. Acknowledgment
9. References

1. ABSTRACT

This chapter reviews the existing evidence on the auditory processes that are responsible for the formation of auditory percepts in natural listening situations ('the auditory scene'). The formation of the perceptual attributes of auditory events is explained as the result of the interaction of two types of auditory grouping processes, general-purpose and schema-based processes. A further distinction is made between attribute-specific and categorical schemas. After discussing the formation of perceptual attributes and of the timbre of familiar sounds, the chapter explores current knowledge on how the brain builds perceptual representations of simultaneous auditory events and of sequences of auditory events. The nature of auditory scene analysis processes and of their interactions is discussed, and a tentative interactive model is proposed as a framework for future research.