Interaural correlation discrimination from diffuse field reference correlations.

Just noticeable differences in interaural correlation (ρ-jnds) from diffuse sound field reference correlations are obtained. In a three-interval, three-alternative forced-choice procedure, ρ-jnds are measured for positive and negative deviations from nine narrowband reference conditions. Stimuli are 1 equivalent rectangular bandwidth wide noise bursts with center frequencies between 165 and 1500 Hz. The frequency dependent reference correlation (ρref) is determined by the simulated interaural correlation under ideal diffuse sound field conditions. Results show that the interaural correlation at threshold for deviation toward the positive correlation range follows the reference curve in a nonlinear fashion. For deviation toward the negative correlation range the interaural correlation at threshold is further afar the reference curve and does not markedly resemble its trend. The results indicate that the previously found asymmetry for correlation discrimination from uncorrelated broadband stimuli to the positive and negative correlation range becomes less pronounced for narrowband stimuli. For positive deviation, the highest jnds are found for the region where the reference curve occupies the global minimum in ρref; despite that, the interaural correlation at threshold for positive deviation exhibits its lowest value at that point.