Estimating the azimuth and elevation of a sound source from the output of a cochlear model

Interaural intensity differences (IIDs) and interaural time differences (ITDs) give important information for estimating the elevation as well as the azimuth of a sound source. The authors extract this information from a filter-bank model of the cochlea using straightforward short-time autocorrelation and crosscorrelation operations. With the appropriate coordinate system, the resulting ITD varies primarily with azimuth, while the IID varies with azimuth and elevation. For a single sound source in an anechoic environment, a maximum-likelihood estimation procedure is shown capable of recovering azimuth to within 1 degree and elevation to within 16 degrees