A Dynamics-based Approach to Sound Source Determination

What information in a sound allows us to identify its source? If the physical properties of the source (and the force driving it) are known, then theoretically it is possible to determine the sound it will produce. The inverse problem is rarely as simple. If one is uncertain regarding the source, then recovering source properties from the sound, analytically, can prove quite difficult. The human auditory system excels at this task, even in the face of enormous uncertainty regarding possible sources. How it does this though remains largely a mystery. In this project we take a novel approach to investigate human identification of real sound sources. Using the principles of theoretical acoustics, we reconstruct the sound pressure waveform at the ear as it is generated by a number of simple resonant objects. We then examine the listenerŐs ability to detect the lawful covariation among parameters of the resultant acoustic waveform. By measuring correlates between various features of the waveform and the listeners response we are able to identify the relevant aspects of the dynamic variation in the acoustic signal that listeners use to identify these sources.

Selected Publications

Lutfi, R. A., and Oh, E. (1994). Auditory discrimination based on the physical dynamics of a tuning fork. Journal of the Acoustical Society of America, 95. 2963. * Wang, W., and Lutfi, R. A. (1994). Thresholds for detection of a change in the displacement, velocity, and acceleration of a synthesized sound-emitting source. Journal of the Acoustical Society of America, 95, 2897. * Lutfi, R. A. (1994). Correlation coefficients and correlation ratios as estimates of observer weights in multiple-observation tasks. Journal of the Acoustical Society of America, 97, 1333-1334. * Lutfi, R. A. (1994a). Discrimination of random, time-varying spectra with statistical constraints. Journal of the Acoustical Society of America, 95, 1490-1500. * Lutfi, R.A., and Oh, Eunmi (1997). Auditory discrimination of material changes in a struck, clamped bar. Journal of Acoustical Society of America. (in press).