Parametric multidirectional decomposition of microphone recordings for broadband high-order ambisonic encoding

Higher-order Ambisonics (HOA) is a flexible recording and reproduction method, which makes it attractive for several applications in virtual and augmented reality. However, the recording of HOA signals with practical compact microphone arrays is limited to a certain frequency range, which depends on the applied microphone array. In this paper, we present a parametric signal-dependent approach that improves the HOA signals at all frequencies. The presented method assumes that the sound field consists of multiple directional components and a diffuse part. The performance of the method is evaluated in simulations with a rigid microphone array in different direct-to-diffuse and signal-to-noise ratio conditions. The results show that the proposed method has a better performance than the traditional signal-dependent encoding in all the simulated conditions.