Perceptual independence of excitor and resonator properties in percussive instrument sounds

Abstract

The perceptual independence of various sensory dimensions has been studied using a speeded classification paradigm developed by Garner. In this paradigm the speed of classification of items varied along one dimension is compared to the same classification when random variation along a second dimension is present. Perceptual interaction is inferred when performance in the latter is slower or worse compared to the former. Such interactions have been shown for simple dimensions such as pitch, loudness, and a spectral dimension of timbre. The present study tested the independence of complex dimensions with overlapping spectral and temporal characteristics. One dimension consisted of the hardness of a percussion mallet (excitor property) and the other of either xylophone bar density or tympani size (resonator properties). These complex source-related dimensions show evidence of interaction in both performance scores and reaction times. A greater independence is found when unrelated variation is introduced along a third dimension (striking force), although performance scores decrease globally. The results are discussed in terms of previously reported interactions among simple dimensions and interactions among complex source properties.