THE REPRESENTATION OF AUDITORY SOURCE CHARACTERISTICS - SIMPLE GEOMETRIC FORM

Two experiments examined Listeners' ability to discriminate the geomet ric shape of simple resonating bodies on the basis of their correspond ing auditory attributes. In cross-modal matching tasks, subjects liste ned to recordings of pairs of metal bars (Experiment 1) or wooden bars (Experiment 2) struck in sequence and then selected a visual depictio n of the bar cross sections that correctly represented their relative widths and heights from two opposing pairs presented on a computer scr een. Multidimensional scaling solutions derived from matching scores f or metal and wooden bars indicated that subjects' performance varied d irectly with increasing differences in the width/height (W/H) ratios o f both sets of bars. Subsequent acoustic analyses revealed that the fr equency components from torsional vibrational modes and the ratios of frequencies of transverse bending modes in the bars correlated strongl y with both the bars' W/H ratios and bar coordinates in the multidimen sional configurations. The results suggest that listeners can encode t he auditory properties of sound sources by extracting certain invarian t physical characteristics of their gross geometric properties from th eir acoustic behavior.