On the perception of density and stratification in granular sonic textures: An exploratory study

This study explores the nature of the perceptual phenomena which arise through qualitative determinations of the stranular density of musical textures (i.e. the number of short atacks which occur per second within specified frequency bounds). Most important at this exploratory stage of research is the description of the varying perceptual phenomena which emerged at various approximate temporal densities and bandwidths. Successively increased temporal densities trace a spectrum of impressions ranging from the simple “sequence” of tones to that of a “flow”, a “swarm”, a fused “textural band” and finally a “massed sonority” depicting the different degree of density‐determined solidity and consistency of the texture under the various quantitative determinations. Successively increased bandwidths with comparable granular densities give rise to a spectrum of impressions of stratification ranging from a noise band to band‐widths with very prominent upper and lower edges but no clearly perceiveable tonal identities in the middle, to bandwidths with very prominent lower edges and mildly prominent upper edges and some fleetingly identifiable tonal content in the middle of the bandwidth. All of these effects are apparently determined by the actual bandwidth. Many of the exploratory findings of the study can be related to the existing literature on the perception of noise bands but the effects of stratification of wider bandwidths and the resultant impressions of spatial resonance at greater temporal densities seem to require more systematic exploration.