Optimal multi-pitch estimation using the EM algorithm for co-channel speech separation

The problem of optimally estimating (in the maximum-likelihood sense) the pitch of each of several speakers talking simultaneously is addressed. This information is needed in systems which perform co-channel speech separation. A multipitch model is proposed which is used in conjunction with an EM (expectation maximization)-based iterative estimation scheme. The pitch period of each speaker is allowed to vary linearly in the analysis interval, thus offering improved cochannel speech separation. The proposed algorithm is shown to outperform standard pitch detection algorithms in detecting the pitch of simultaneous speakers. The proposed multipitch detection algorithm has potential in improving the performance of speaker separation and in interference suppression systems.<>