| 摘要 |
A telephone long distance service is provided using speaker verification to determine whether a user whether a user is a valid user or an impostor. The user claims an identity by offering some form of identification, typically by entering a calling card number on the phone's touch-tone keypad or by magnetic strip on the card which is read by the telephone. Unrestricted, extemporaneous speech of a group of customers are digitized, analyzed in accordance with a PCM circuit, and characterized as a non-parametric set of speech feature vectors. The extemporaneous speech of the long distance telephone service user claiming the identity of a service customer via his card number is digitized and analyzed in a like manner. The identity of the user is verified by comparing, either during or after the call, the signals in accordance with an algorithm which compares a reference utterance of a known customer with input utterances from one or more unknown telephone service users, one of which users has claimed the identity of the customer. This comparison results in a decision to accept or reject the hypothesized identity. The identity hypothesis to be tested is thus derived from the calling card of the customer. <IMAGE> |
