Ambisonic room impulse responses extrapolation guided by single microphone measurements

Sound fields and room impulse responses represented using higher-order-Ambisonics (HOA) is an efficient way to generate six-degree-freedom (6DoF) binaural rendering. However, measuring the room impulse responses of the entire space is impractical in reality. While many methods have been proposed for Ambisonic room impulses response (ARIR) interpolation and extrapolation, in this work, we propose a robust ARIR extrapolation method by combing the ARIR, which is measured at a fixed point inside the room, with the monaural RIR measured at the extrapolation point. The ARIR is decomposed into a direct part, distinct early reflections, and the residual reverberation. For the direct and early reflection parts, extrapolation is performed by estimating the source positions based on a parametric analysis of the measured ARIR and monaural RIR. The extrapolation of the residual reverberation is achieved by manipulating the monaural RIR, where the weights are derived from ARIR measurements. Finally, objective and subjective evaluations are conducted to evaluate the accuracy and robustness of the proposed method. The results show that the proposed method approximates the true ARIR in terms of objective indicators and subjective perception.