Co-Channel Speech and Speaker Identification Study.

摘要

This study was comprised of two parts. The first was to determine the effectiveness of speaker identification under two different speaker identification degradation conditions, additive noise and speaker interference, using the LPC cepstral coefficient approach. The second part was to develop a method for determination of co-channel speech, i.e., speaker count, and to develop an effective method of either speech extraction or speech suppression to enhance the operation of speaker identification under co-channel conditions. The results of the first part of study indicate that under conditions of the same amount of either noise or corrupting speech, for example 0 dB SNR or TIR (target-to-interference ratio), noise is much more detrimental than corrupting speech to the operation of the speaker identification. For example, with 100% of 0 dB corrupting speech there still occurs a certain number of correct speaker identifications, i.e., about 40% accuracy. Ten (10) dB TIR interfering speech, as well as small amounts of interfering speech, i. e., 40% 0 dB TIR are not as detrimental to speaker identification. The results of the second part of the study indicate that a system for speaker count and speaker separation is possible. The harmonic sampling approach, developed during the study, uses the periodic structure of the fine structure of the frequency characteristics of voiced speech. Successful reconstruction of a single speaker indicates the potential of this approach as a candidate for speech separation. Also, it was shown that detection of co-channel speech is possible using the harmonic sampling approach. Further improvements as well as other possible approaches to the co-channel speech problem are discussed.