ASA 124th Meeting New Orleans 1992 October

1pPP12. Identification of multidimensional complex sounds having parallel dimension structure.

Laurel A. Christopherson

Dept. of Commun. Disord., Louisiana State Univ. Med. Ctr., 1900 Gravier St., New Orleans, LA 70112-2262

Larry E. Humes

Charles S. Watson

Gary R. Kidd

Indiana Univ., Bloomington, IN 47405

Ten listeners classified complex sound pulses that differed on three independent and discriminable dimensions. The stimuli were 100-ms sound pulses synthesized using five simultaneous sinusoids used previously by Kidd and Watson [J. Acoust. Soc. Am. Suppl. 1 81, S33 (1987)]. The three dimensions of the stimuli were harmonicity, spectral shape, and amplitude envelope. Each dimension could take on one of two possible values, target or nontarget. Eight stimuli were synthesized using all possible combinations of the dimension values. Subjects were trained to label two stimuli, the two having either all-target or all nontarget values, as ``+'' and ``0,'' respectively. Following this training, subjects were asked to classify all eight stimuli as either ``+'' or ``0.'' Results indicated that listeners preferred one dimension when classifying the stimuli. However, the preferred dimension was not the same for all of the listeners. In addition, it was demonstrated that listeners could be trained to use a dimension that they previously were not using to classify the sound pulses. [Work supported by NIA and AFOSR.]