Experimental studies in a new automatic speaker verification system using telephone speech

New techniques for automatic speaker verification are described which are based on cepstral analysis of fixed sentence-long utterances. Utterances are represented by time functions of cepstral coefficients expanded by an orthogonal polynomial. Sample utterance representations are compared with similarly constituted reference patterns to decide whether to accept or reject an identity claim. A dynamic programming technique is used to bring sample utterance representations into time registration with reference patterns. A local distance measurement is summed along the optimal path associated with the time registration to provide an overall distance which is compared with a threshold to effect the decision. Results of an evaluation using prerecorded utterance sets including telephone speech are presented. Verification error rates less 1% are obtained.