Representation of musical timbre in the auditory cortex*

Abstract

Abstract Musical sounds are usually characterized by their pitch, timbre, loudness, forms of modulation, and onset/offset instants. These descriptions of sound quality have a close relationship to the instantaneous spectral properties of the sound waves. Physiological, psychoacoustical, and computational studies reveal that the central auditory system has developed elegant mechanisms to extract and represent this spectro‐temporal information. For instance, the primary auditory cortex (AI) employs a multiscale representation in which the dynamic spectrum is repeatedly represented in AI at various degrees of spectral and temporal resolution. This is accomplished by cells whose responses are selective to a range of spectro‐temporal parameters such as the local bandwidth and asymmetry of spectral peaks, and their onset and offset transition rates. Such a representation provides a quantitative description of the timbral quality of sound, and hence can be used to extrapolate between canonical timbres to synthesize novel sounds. Notes Sound examples are available in the JNMR Electronic Appendix (EA) which can be found on the WWW at http://www.sweis.nl/jnrnr/jnmr.html