Broadband direction estimation method utilizing combined pressure and energy gradients from optimized microphone array

This paper proposes a method for analyzing the direction of the arrival of sound by estimating the sound intensity vector from the pressure and energy gradients of closely-spaced omnidirectional microphones depending on frequency. Microphones with relatively large housing, which cause shadowing, are used here to provide inter microphone level differences in order to compute the energy gradients at high frequencies. The proposed method is evaluated in the direction analysis of a spatial-sound processing technique, Directional Audio Coding (DirAC). It is shown that the method provides a reliable direction estimation at the entire audio frequency range, whereas the traditional method employing the pressure gradients produces correct estimation in a limited frequency window only.