Nonlinear response in evaluating the subjective diffuseness of sound fields.

Tests were conducted to determine which horizontal reflection angles are most effective in stimulating subjective diffuseness for a listener in a room. Paired comparison tests were carried out where subjects were asked to judge in which of two sound fields they perceived more diffuseness. Results show that the most effective horizontal angle depends on the frequency of the one-third-octave-band noise, as is indicated by the interaural cross correlation. The remarkable finding in this investigation is that the scale value of subjective diffuseness may be formulated in terms of the 3/2 power of the magnitude of interaural cross correlation (IACC) and that the scale value does not vary with the frequency of the bandpass noise source.