Single-Channel Speech-Music Separation for Robust ASR With Mixture Models

In this study, we describe a mixture model based single-channel speech-music separation method. Given a catalog of background music material, we propose a generative model for the superposed speech and music spectrograms. The background music signal is assumed to be generated by a jingle in the catalog. The background music component is modeled by a scaled conditional mixture model representing the jingle. The speech signal is modeled by a probabilistic model, which is similar to the probabilistic interpretation of Non-negative Matrix Factorization (NMF) model. The parameters of the speech model is estimated in a semi-supervised manner from the mixed signal. The approach is tested with Poisson and complex Gaussian observation models that correspond respectively to Kullback-Leibler (KL) and Itakura-Saito (IS) divergence measures. Our experiments show that the proposed mixture model outperforms a standard NMF method both in speech-music separation and automatic speech recognition (ASR) tasks. These results are further improved using Markovian prior structures for temporal continuity between the jingle frames. Our test results with real data show that our method increases the speech recognition performance.