Benjamin, E. and Lee, R. and Heller, A. Localization in Horizontal-Only Ambisonic Systems. 121st Convention of the Audio Engeineering Society, Oct 2006.
Ambisonic reproduction systems are unique in their ability to separately reproduce the pressure and velocity components of recorded audio signals. Gerzon proposed a theory of localization in which the human auditory system is presumed to localize using the direction of the velocity vector in the reproduced sound at low frequencies, and the energy vector at high frequencies. An Ambisonic decoder has the energy and velocity vectors coincident. These are the directions of the apparent source when the listener can turn to face it. Separately optimizing the low-frequency and mid/high-frequency operation of the reproduction system can optimize localization where the listener cannot turn to face the apparent source. We test the localization of horizontal-only Ambisonic reproduction systems using various test signals to separately evaluate low-frequency and mid-frequency localization.