A set of equations for numerically calculating the interaural level difference in the horizontal plane.

The variation of interaural level difference (ILD) with direction and frequency is particularly complex and convoluted. The purpose of this work was to determine a set of parametric equations that can be used to calculate ILDs continuously at any value of frequency and azimuth in the horizontal plane. They were derived by fitting equations to ILDs derived from the azimuthal-dependence data tabulated by Shaw and Vaillancourt [(1985). J. Acoust. Soc Am. 78, 1120-1123] and assuming left-right symmetry. The equations are shown to fit those data to an overall RMS error less than 0.5 dB.