Specifying the perceptual relevance of onset transients for musical instrument identification

Previous research suggests that sound onsets play a privileged role in the identification of musical instruments, but the underlying acoustic features remain unclear. By using sounds resynthesized with and without rapidly varying transients (not to be confused with the onset as a whole), this study set out to specify precisely the role of transients and quasi-stationary components in the perception of musical instrument sounds. In experiment 1, listeners were trained to identify ten instruments from 250 ms sounds. In a subsequent test phase, listeners identified instruments from 64 ms segments of sounds presented with or without transient components, either taken from the onset, or from the middle portion of the sounds. The omission of transient components at the onset impaired overall identification accuracy only by 6%, even though experiment 2 suggested that their omission was discriminable. Shifting the position of the gate from the onset to the middle portion of the tone impaired overall identification accuracy by 25%. Taken together, these findings confirm the prominent status of onsets in musical instrument identification suggested by the literature, but suggest that rapidly varying transients are less indicative of instrument identity compared to the relatively slow build-up of sinusoidal components during onsets.