TY - JOUR
T1 - Perceptual fusion and fragmentation of complex tones made inharmonic by applying different degrees of frequency shift and spectral stretch
AU - Roberts, Brian
AU - Brunstrom, Jeffrey
PY - 2001/11/1
Y1 - 2001/11/1
N2 - Global pitch depends on harmonic relations between components, but the perceptual coherence of a complex tone cannot be explained in the same way. Instead, it has been proposed that the auditory system responds to a common pattern of equal spacing between components, but is only sensitive to deviations from this pattern over a limited range [Roberts and Brunstrom, J. Acoust. Soc. Am. 104, 2326-2338 (1998)]. This hypothesis predicts that spectral fusion will be largely unaffected either by frequency shifting a harmonic stimulus (because equal spacing is preserved), or by small degrees of spectral stretch (because significant deviations from equal spacing only cumulate over large spectral distances). Complex tones were either shifted by 0%-50% of F0 (200 Hz+/-10%) or stretched by 0%-12% of F0 (100 Hz+/-10%). Subjects heard a complex followed by a pure tone in a continuous loop. One of the components 2-11 was mistuned by +/- 4%, and subjects adjusted the pure tone to match its pitch. Broadly consistent with our hypothesis, frequency shifts had relatively little effect on hit rates and only large degrees of stretch reduced them substantially. The implications for simultaneous grouping are explored with reference to an autocorrelation model of auditory processing.
AB - Global pitch depends on harmonic relations between components, but the perceptual coherence of a complex tone cannot be explained in the same way. Instead, it has been proposed that the auditory system responds to a common pattern of equal spacing between components, but is only sensitive to deviations from this pattern over a limited range [Roberts and Brunstrom, J. Acoust. Soc. Am. 104, 2326-2338 (1998)]. This hypothesis predicts that spectral fusion will be largely unaffected either by frequency shifting a harmonic stimulus (because equal spacing is preserved), or by small degrees of spectral stretch (because significant deviations from equal spacing only cumulate over large spectral distances). Complex tones were either shifted by 0%-50% of F0 (200 Hz+/-10%) or stretched by 0%-12% of F0 (100 Hz+/-10%). Subjects heard a complex followed by a pure tone in a continuous loop. One of the components 2-11 was mistuned by +/- 4%, and subjects adjusted the pure tone to match its pitch. Broadly consistent with our hypothesis, frequency shifts had relatively little effect on hit rates and only large degrees of stretch reduced them substantially. The implications for simultaneous grouping are explored with reference to an autocorrelation model of auditory processing.
UR - http://www.scopus.com/inward/record.url?scp=0035168074&partnerID=8YFLogxK
U2 - 10.1121/1.1410965
DO - 10.1121/1.1410965
M3 - Article
C2 - 11757937
VL - 110
SP - 2479
EP - 2490
JO - The Journal of the Acoustical Society of America
JF - The Journal of the Acoustical Society of America
ER -