Auditory perception of fractal contours.
A series of experiments examined auditory contour formation, investigating listeners' sensitivities to a family of random fractals known as fractional Brownian noises. Experiments 1A and 1B looked at identification of contours when 3 different noises were portrayed using variations in the pitch, duration, or loudness of successive notes of a sequence. Listeners could categorize pitch and loudness encodings, but not duration mappings. Experiment 2 looked at the effect of simultaneous presentation of pitch and loudness information, finding that these dimensions combined additively to increase identification of the noise distributions. Experiment 3 looked at discrimination of pitch contours as a function of changing fractal dimension. Discrimination curves approximated an inverted U shape, a finding that is not understandable in terms of sensitivity to differences in fractal dimension per se, nor in terms of "tuned" perceptual sensitivity to statistical regularities of the environment.
Schmuckler
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MA
Division of Life Sciences, University of Toronto, Scarborough, Ontario, Canada.
Gilden
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DL
D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception; D002648:Child; D005260:Female; D006801:Humans; D008144:Loudness Perception; D008297:Male; D009622:Noise; D010898:Pitch Perception; D013997:Time Factors