Global Patent Index - EP 0335521 A1

EP 0335521 A1 19891004 - Voice activity detection.

Title (en)

Voice activity detection.

Title (de)

Detektion für die Anwesenheit eines Sprachsignals.

Title (fr)

Détection de la présence d'un signal de parole.

Publication

EP 0335521 A1 19891004 (EN)

Application

EP 89302422 A 19890310

Priority

  • GB 8805795 A 19880311
  • GB 8813346 A 19880606
  • GB 8820105 A 19880824

Abstract (en)

Voice activity detector (VAD) for use in an LPC coder in a mobile radio system, uses autocorrelation coefficients R0, R1..... of the input signal, weighted and combined, to provide a measure M which depends on the power within that part of the spectrum containing no noise, which is thresholded against a variable threshold to provide a speech/no speech logic output. The measure is <MATH> where Hi are the autocorrelation coefficients of the impulse response of an Nth order FIR inverse noise filter derived from LPC analysis of previous non-speech signal frames. Threshold adaption and coefficient update are controlled by a second VAD responsive to rate of spectral change between frames.

IPC 1-7

G10L 3/00; G10L 9/08

IPC 8 full level

G10L 25/00 (2013.01); G10L 25/78 (2013.01)

CPC (source: EP KR)

G10L 25/00 (2013.01 - EP); G10L 25/78 (2013.01 - EP KR); G10L 25/84 (2013.01 - KR)

Citation (search report)

  • [X] US 4358738 A 19821109 - KAHN LEONARD R
  • [A] US 4052568 A 19771004 - JANKOWSKI JOSEPH ALBIN
  • [A] EP 0127718 A1 19841212 - IBM [US], et al
  • [A] US 4688256 A 19870818 - YASUNAGA SATOSHI [JP]
  • [A] GB 2061676 A 19810513 - MARCONI CO LTD
  • [A] EP 0178933 A2 19860423 - SHARP KK [JP]
  • [X] IEEE TRANSACTIONS ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING, vol. ASSP-25, no. 4, August 1977, pages 338-343, New York, US; L.R. RABINER et al.: "Application of an LPC distance measure to the voiced-unvoiced-silence detection problem"
  • [A] ICASSP'81 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING, Atlanta, 30th March - 1st April 1981, vol. 3, pages 1082-1085, IEEE, New York, US; C.K. UN et al.: "Improving LPC analysis of noisy speech by autocorrelation subtraction method"
  • [A] 1977 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH, and SIGNAL PROCESSING, Hartford, Connecticut, 9th-11th May 1977, pages 425-428, IEEE, New York, US; R.J. McAULAY: "Optimum speech classification and its application to adaptive noise cancellation"
  • [A] IBM TECHNICAL DISCLOSURE BULLETIN, vol. 22, no. 7, December 1979, pages 2624-2625, New York, US; R.J. JOHNSON et al.: "Speech detector"
  • [A] IEEE TRANSACTIONS ON COMMUNICATIONS, vol. COM-26, no. 1, January 1978, pages 140-145, IEEE, New York, US; P.G. DRAGO et al.: "Digital dynamic speech detectors"

Designated contracting state (EPC)

AT BE CH DE ES FR GB GR IT LI LU NL SE

DOCDB simple family (publication)

EP 0335521 A1 19891004; EP 0335521 B1 19931124; AU 3355489 A 19891005; AU 608432 B2 19910328; BR 8907308 A 19910319; CA 1335003 C 19950328; DE 68910859 D1 19940105; DE 68910859 T2 19941208; DE 68929442 D1 20030123; DE 68929442 T2 20031002; DK 175478 B1 20041108; DK 215690 A 19900907; DK 215690 D0 19900907; EP 0548054 A2 19930623; EP 0548054 A3 19940112; EP 0548054 B1 20021211; ES 2047664 T3 19940301; ES 2188588 T3 20030701; FI 110726 B 20030314; FI 115328 B 20050415; FI 20010933 A 20010504; FI 904410 A0 19900907; HK 135896 A 19960802; IE 61863 B1 19941130; IE 890774 L 19890911; JP 2000148172 A 20000526; JP 3321156 B2 20020903; JP 3423906 B2 20030707; JP H03504283 A 19910919; KR 0161258 B1 19990320; KR 900700993 A 19900817; NO 304858 B1 19990222; NO 316610 B1 20040308; NO 903936 D0 19900910; NO 903936 L 19901109; NO 982568 D0 19980604; NO 982568 L 19901109; NZ 228290 A 19920129; PT 89978 A 19891110; PT 89978 B 19950301; WO 8908910 A1 19890921

DOCDB simple family (application)

EP 89302422 A 19890310; AU 3355489 A 19890310; BR 8907308 A 19890310; CA 593386 A 19890310; DE 68910859 T 19890310; DE 68929442 T 19890310; DK 215690 A 19900907; EP 93200015 A 19890310; ES 89302422 T 19890310; ES 93200015 T 19890310; FI 20010933 A 20010504; FI 904410 A 19900907; GB 8900247 W 19890310; HK 135896 A 19960725; IE 77489 A 19890310; JP 32819899 A 19991118; JP 50377289 A 19890310; KR 890702099 A 19891109; NO 903936 A 19900910; NO 982568 A 19980604; NZ 22829089 A 19890310; PT 8997889 A 19890310