American Psychological Association, Inc. Auditory Perception of Breaking and Bouncing Events: A Case Study in Ecological Acoustics

The mechanical events of bouncing and breaking are acoustically specified by single versus multiple damped quasi-periodic pulse patterns, with an initial noise burst in the case of breaking. Subjects show high accuracy in categorizing natural tokens of bouncing and breaking glass as well as tokens constructed by adjusting only the temporal patterns of components, leaving their spectral properties constant. Differences in average spectral frequency are, therefore, not necessary for perceiving this contrast, though differences in spectral consistency over successive pulses may be important. Initial noise corresponding to glass rupture appears unnecessary to categorize breaking and bouncing. The data indicate that higher order temporal properties of the acoustic signal provide information for the auditory perception of these events. Research in auditory perception has tended to emphasize the detection and processing of sound elements with quasi-stable spectral structure, such as tones, formants, and bursts of noise. In the spectral domain, these ele-ments are distinguished by frequency peak or range, bandwidth, and amplitude. In the temporal domain, acoustic analysis has often focused on the durations of sound elements, the intervals and phase relations between them, and the influence of these on pitch and loudness perception, temporal acuity, mask-ing, and localization. The auditory system has often been approached as an analyzer of essentially time-constant functions of fre-quency, amplitude, and duration, on the as-sumption that complex auditory percepts are compositions over sound elements having those properties, with certain temporal inter