William J. Strong Sining Li
Dept. of Phys. and Astron., Brigham Young Univ., Provo, UT 84602
Transmission of sound in a large room was simulated by means of an image method incorporating artificial diffusion. The simulation model was validated by comparing the standard deviations of its transmission spectra to theoretical and experimental results obtained by others. Several combinations of source and receiver positions were simulated in order to assess their effects on spectral variability. A single source and single receiver arrangement resulted in the greatest variability as expected. Other combinations, including single-source/two-receiver (to represent two ears), two-source (to represent spatial extent of source)/two-receiver, and five-source/five-receiver, were used to assess their effects. The effects of frequency modulation and critical bands of the ear were also simulated. In an attempt to relate simulation results to stability in perception, a limit of 6-dB difference in relative harmonic levels between received tones and source tones was chosen as the criterion. On the basis of this criterion, a single-source and two-receiver arrangement incorporation critical band effects and frequency modulation was found adequate to provide stable perception.