ASA 124th Meeting New Orleans 1992 October

3pPP4. Comparison of displacement thresholds in auditory and visual modalities.

Jennifer M. Ball

David R. Perrott

Geoff A. Booth

John Cisneros

Psychoacoust. Lab., California State Univ., Los Angeles, CA 90032

Previous research of moving sound sources show an increase of minimal displacements as a direct function of velocity. The current experiment attempted to establish upper limits for this function. Five subjects were tested, three naive and two experienced. MAMA thresholds for velocity ranging from 10 to 1500 deg per second were obtained using a three-up one-down adaptive procedure. For comparison purposes, visual targets were also employed in the paradigm. For velocities in excess of 100 deg per second, auditory displacement thresholds were substantially lower than those obtained for vision. However, the superiority of the visual modality was evident at lower rates of travel. These results will be discussed relative to our hypothesis that the auditory system may have a significant role in oculomotor processes.