Patent
1993-04-05
1996-06-11
MacDonald, Allen R.
395 252, 395 265, G10L 506, G10L 900
Patent
active
055264654
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to verifying that a sequence of operations has been carried out by a specific entity. Usually the entity is a person and the sequence of operations may, for example, be speaking a digit or a letter, or writing a letter or a word. Thus the invention relates particularly to the verification that an utterance was made by a predetermined person, but it is believed that the invention can be applied to other actions carried out by persons such as recognising written words.
2. Description of the Related Art
Speech recognition using Hidden Markov Models (HMM) is a well known technique and HMMs have also been applied to signature verification. Speaker verification is important in many applications, particularly where financial transactions are to be carried out automatically by telephone and where access to premises is to be controlled. False acceptances of speech are likely to cause serious problems when unauthorised transactions or access are allowed. Almost as important are false rejections where a person who should be verified is not. False rejections cause annoyance especially when they occur frequently.
Speech verification over telephone links raises its own problems due to the limited bandwidth of such links and distortion which often occurs.
Three previous examples of speaker verification systems are described in U.S. Pat. Nos. 4,363,102, 4,694,493 and 4,910,782.
According to a first aspect of the present invention there is provided a method of verifying that a sequence of operations originates from a specific entity, comprising the steps of
extracting a test sequence of sets of features of the results of the operations, one set corresponding to each operation,
matching the said test sequence of sets of features against a first stored probabilistic finite state machine model derived from sets of features of the results of the same sequence of operations when originated by a plurality of entities,
matching the said test sequence of features against a second stored finite state machine model derived from sets of features of the results of the same sequence of operations when originated by the specific entity, and
comparing the results of the matching steps to indicate whether the test sequence of operations originated from the specific entity.
According to a second aspect of the invention there is provided apparatus for verifying that a sequence of operations originated from a specific entity, comprising
means for storing data specifying first and second finite state machines, the data for the first machine having been derived from sets of features of the results of a sequence of operations originated by a plurality of entities, the data for the second machine having been derived from sets of features of the results of the same sequence of operations originated by a specific entity,
means for extracting a test sequence of sets of features from the results of a sequence of operations which are alleged to have been originated by the said specific entity,
means for matching the said test sequence against the first and second said machines, respectively, and
means for comparing results from the matching means to indicate whether the test sequence was originated by the said specific entity.
The specific entity is usually a person, although the entity may be an object, for example an object undergoing non-destructive testing when the sequence of operations may be signals originated by the object under test. As has been mentioned, where the entity is a person the sequence of operations may, for example, be the utterance of a sound or the signing of a signature. The sounds may be alpha-numeric characters or words and the characters or words may be uttered as isolated items, or connected items as in continuous speech.
The invention has the advantage that it tends to reduce false acceptances and false rejections in speaker verification.
Signals resulting from incoming speech may be digitized at relatively short intervals and processed
REFERENCES:
patent: 4694493 (1987-09-01), Sakoe
patent: 4783804 (1988-11-01), Juang et al.
patent: 4910782 (1990-03-01), Watari
patent: 5033087 (1991-07-01), Bahl et al.
patent: 5293452 (1994-03-01), Picone et al.
patent: 5311601 (1994-05-01), Carpenter et al.
A Speaker Verification System Using Alpha Nets Carey et al. IEEE/May 1991.
Speaker Identification and Verification via Singular Value decomposition of speech parameters. Mahil et al IEEE/Aug. 1990.
Speaker Verification Over Long Distance Telephone Lines Naik et al. IEEE/May 1989.
Voice and Speech Processing Parsons McGraw-Hill, Inc. 1987.
N. Tishby, "Information Theoretic Factorization of Speaker and Language in Hidden Markov Models, etc.", ICASSP 88/1988 International Conference on Acoustics, etc., Apr. 11-14, 1988, vol. 1, IEEE New York, pp. 87-90.
J. M. Naik et al., "Speaker Verification Over Long Distance Telephone Lines", ICASSP '89/1989 International Conference on Acoustics, etc., May 23-26, 1989, vol. 1, IEEE New York, pp. 524-526.
J. M. Naik, "Speaker Verification: A Tutorial", IEEE Communications Magazine, vol. 28, No. 1, Jan. 1990 (New York) pp. 42-48.
J. E. Luck, "Automatic Speaker Verification Using Cepstral Measurements", The Journal of the Acoustical Society of America, vol. 46, No. 4, part 2, 1969 (New York), pp. 1026-1032.
G. Velius, "Variants of Cepstrum Based Speaker Identity Verification", ICASSP 88/1988 International Conference on Acoustics, etc., Apr. 11-14, 1988, vol. 1, IEEE, New York, pp. 583-586.
H. Gish, "Robust Discrimination in Automatic Speaker Identification", ICASSP '90/1990 International Conference on Acoustics, etc., Apr. 3-6, 1990, Albuquerque US, vol. 1, IEEE New York, pp. 289-292.
F. K. Soong et al., "On the Use of Instantaneous and Transitional Spectral, etc.", IEEE Transactions on Acoustics, etc., vol. 36, No. 6, Jun. 1988, New York, pp. 871-879.
Bridle John S.
Carey Michael J.
Parris Eluned S.
Dorvil Richemond
Ensigma Limited
MacDonald Allen R.
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