Binaural interaction of transients: Interaural time and intensity asymmetry

When subjects are required to make a forced choice between pairs of pulses dichotic with respect to time (Δt ) from pairs of pulses dichotic with respect to intensity (ΔI), the resultant data appear as V-shaped functions relating discrimination accuracy to interaural time asymmetry (ΔI). The sharpness of the limbs (the spread of the functions), the appearance of a well-defined minimum, the Δt at which the minimum point is found, and the accuracy of discrimination at the minimum point of the function depend upon the parameters of summed binaural sensation level, and the interaural intensity asymmetry. The interaural time asymmetry (Δt) associated with the minimum point of the function can be used as an index of the degree to which Δt can be matched to ΔI when the parameters of ΔI and summed binaural sensation level are varied. The ratio of Δt associated with the minimum of the function to ΔI, i.e., Δt/ΔI in microseconds/dB, is found to be inversely related to summed binaural sensation level.