Audio-Based Estimation of Speakers Directions for Multimedia Meeting Logs

This paper is concerned with an audio-based method for estimating speaker directions in meeting environment. It is well-known that cross-power spectrum phase (CSP) analysis is a very powerful tool for localizing sound sources. However, when we adopt the CSP-based method together with a circular microphone array system to estimate the speaker directions in 360-degree range (e.g. round-table discussions), the method fails to estimate the directions due to the existence of imaginary peaks of CSP coefficients. In order to circumvent the above problem, we propose a method to suppress the imaginary peaks, which uses a circular-array version of the method proposed by Nishiura and appropriate scaling around the imaginary peaks. Experimental results are also shown to demonstrate the effectiveness of the proposed method.