Recent research in musical timbre perception.

Abstract

Various methods have been used in an attempt to reveal salient parameters for musical timbre perception and to estimate perceptual distances between timbres based on their spectra. The multidimensional scaling method compares exemplars of musical sounds using listener estimation of timbral dissimilarity between sound pairs. Data are coalesced into a space whose dimensions are easily interpretable in terms of acoustic parameters such as spectral centroid, spectral flux, spectral irregularity, and attack time. Sounds can be normalized with respect to some parameters in order to reveal others. The direct comparison method attempts to discover how discrimination, recognition, and degree of perceptual dissimilarity depend on the degree of modification of the time-varying spectrum or of particular features of the spectrum. Morphing between spectrum pairs is one method of producing spectral modifications. Dissimilarity can be predicted by computing a “distance” between two time-varying spectra. For musical sounds, spectral distance has been computed by taking the average Cartesian distance between spectral measures treated as vectors. For constant-F0 sounds, the most obvious vector is the set of harmonic amplitudes, either in linear or decibel units. Other vectors are based on critical bands and cepstral coefficients. [Work supported by Research Grants Council Grant No. 613508.]