Combined monaural and binaural localization of sound sources

In this paper we combine monaural estimates of elevation with binaural estimates of azimuth and elevation. The monaural estimates are derived from the second difference of the amplitude spectrum, and are useful in the median plane, where binaural elevation estimates are very poor; however, they are source dependent, and do not provide azimuth information. The binaural estimates are derived from the interaural intensity difference, and are accurate away from the median plane. For a white-noise source in an anechoic environment, we show that the combination is accurate to within 2/spl deg/ for azimuth and 12/spl deg/ for elevation. Good performance is also obtained for speech, but accuracy degrades as the source bandwidth is reduced.