(19)
(11) EP 1 748 426 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
21.02.2007 Bulletin 2007/08

(43) Date of publication A2:
31.01.2007 Bulletin 2007/05

(21) Application number: 06020682.8

(22) Date of filing: 07.01.2000
(51) International Patent Classification (IPC): 
G10L 21/02(2006.01)
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

(30) Priority: 07.01.1999 US 115245 P

(62) Application number of the earlier application in accordance with Art. 76 EPC:
00902355.7 / 1141948

(71) Applicant: Tellabs Operations, Inc.
Lisle, IL 60532 (US)

(72) Inventors:
  • Chandran, Ravi
    South Bend, IN 46637 (US)
  • Dunne, Bruce E.
    Niles, MI 49120 (US)
  • Marchok, Daniel J.
    Buchanan, MI 49107 (US)

(74) Representative: Reeve, Anna Elizabeth et al
Lloyd Wise, Commonwealth House, 1-19 New Oxford Street
London WC1A 1LW
London WC1A 1LW (GB)

   


(54) Method and apparatus for adaptively suppressing noise


(57) An apparatus and method for suppressing noise is presented. The apparatus may utilize a filter bank of bandpass filters to split the input noisy speech-containing signal into separate frequency bands. The overall average noise-to-signal ration (NSR) of the input signal is estimated in the overall NSR estimator, which estimates the average noisy signal power in the input signal during speech activity and the average noise power during silence. Two indirect power measures are performed for each band, measuring a short-term power and a long-term power. The power estimation processes are adapted based on the signal activity indicated by the JVADAD. An NSR adapter adapts the NSR for each frequency band based on the long-term and short-term power measures, the overall NSR and the signal activity indicated by the JVADAD. The gain computer utilizes these NSR values to determine the gain factors for each frequency band.







Search report