Perceiving changes of sound-source size within musical tone pairs.
Joseph Plazak, Stephen E. McAdams · Psychomusicology Music Mind and Brain · 2017
Recent research suggests that the perception of sound-source size may be based in part on attributes of timbre, and further, that it may play a role in understanding emotional responses to music. Here, we report 2 perceptual studies in which the TANDEM-STRAIGHT vocoder was used to modify musical instrument tones to emulate equivalent instruments of different sizes. In each experiment, listeners heard sequential tone pairs in which tones from the same instrument were manipulated to sound as if they had originated from a larger or smaller source. Manipulations included modifications of both fundamental frequency (f0) and spectral envelope. Participants estimated the direction and magnitude of these size changes. We collected data both with and without RMS normalization of the output of the TANDEM-STRAIGHT vocoder in Experiments 1 and 2, respectively. In both cases, manipulations of f0 and spectral envelope were found to have significant effects on the perception of sound-source size change, although results varied across musical instruments and depended on whether the sounds were equalized in level. The results uncover several important considerations for understanding musical timbre and pitch, and are discussed in light of implications for the perception of musical affect.