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.