| Abstract: | A series of experiments examined auditory contour formation, investigating listeners' sensitivities to a family of random fractals known as fractional Brownian noises. Exps 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. Exp 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. Exp 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
