Speech detection

• US 20020116187A1
• Filed: 10/03/2001
• Published: 08/22/2002
• Est. Priority Date: 10/04/2000
• Status: Abandoned Application

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Inventors: Erten, Gamze
• Application Number:
  US09/971,323
• Publication Number:
  US 20020116187A1
• Time in Patent Office: Days
• US Class Current: 704/233
• CPC Class Codes: G10L 19/0204 using subband decomposition
• CPC Class Codes: G10L 2025/783 based on threshold decision
• CPC Class Codes: G10L 21/0272 Voice signal separating
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10

Abstract

Speech in the presence of noise is detected by first extracting at least one extracted speech signal from at least one received signal and extracting at least one extracted noise signal from the at least one received signal. A detected speech signal is generated based on both at least one extracted speech signal and on at least one extracted noise signal.

Claims

1. A speech detection system comprising:

at least one transducer converting sound into an electrical signal;

a voice extractor in communication with the at least one transducer, the voice extractor producing at least one extracted speech signal and at least one extracted noise signal based on at least one electrical sound signal; and

a speech detector in communication with the voice extractor, the speech detector generating a detected speech signal based on the at least one extracted speech signal and on the at least one extracted noise signal.

2. A speech detection system as in claim 1 wherein the speech detector recognizes periods of speech based on at least one property of the at least one extracted speech signal and on at least one corresponding property of the at least one extracted noise signal.

3. A speech detection system as in claim 1 wherein the speech detector recognizes periods of speech based on statistical properties of the at least one extracted speech signal and on statistical properties of the at least one extracted noise signal.

4. A speech detection system as in claim 1 wherein the speech detector recognizes periods of speech based on spectral properties of the at least one extracted speech signal and on spectral properties of the at least one extracted noise signal.

5. A speech detection system as in claim 1 wherein the at least one transducer is a plurality of transducers, the speech detector recognizing periods of speech based on estimated relative proximity of a speaker to at least two of the plurality of transducers.

6. A speech detection system as in claim 1 wherein the speech detector recognizes periods of speech based on an envelope of the at least one extracted speech signal.

7. A speech detection system as in claim 1 wherein the at least one extracted speech signal is divided in time into a plurality of windows, the speech detector generating the detected speech signal based on determining whether or not speech is present in each window.

8. A speech detection system as in claim 7 wherein the at least one extracted speech signal is divided into a plurality of frequency bands, the speech detector determining whether or not speech is present in each frequency band for each window.

9. A speech detection system as in claim 8 wherein the detected speech signal is based on combining the determination for each frequency band for each window.

10. A speech detection system as in claim 1 further comprising a variable rate coder in communication with the speech detector, the variable rate coder changing a coding rate for coding the detected speech signal based on a determined presence of speech in the detected speech signal.

11. A speech detection system as in claim 1 further comprising a variable rate compressor in communication with the speech detector, the variable rate compressor changing a compression rate for compressing the detected speech signal based on a determined presence of speech in the detected speech signal.

13. A method of detecting speech as in claim 12 wherein the detected speech signal comprises periods wherein the at least one extracted speech signal is attenuated.

14. A method of detecting speech as in claim 12 wherein the detected speech signal comprises a likelihood of speech presence.

15. A method of detecting speech as in claim 12 wherein generating the detected speech signal comprises comparing at least one statistical property from the at least one extracted speech signal with at least one corresponding statistical property from the at least one extracted noise signal.

16. A method of detecting speech as in claim 12 wherein generating the detected speech signal comprises comparing at least one spectral property from the at least one extracted speech signal with at least one corresponding spectral property from the at least one extracted noise signal.

17. A method of detecting speech as in claim 12 wherein receiving at least one signal comprises receiving one signal from each of a plurality of acoustic transducers.

18. A method of detecting speech as in claim 17 wherein generating the detected speech signal is based on relative proximities to a speaker of at least two of the acoustic transducers.

19. A method of detecting speech as in claim 12 wherein generating the detected speech signal comprises comparing at least one envelope property from the at least one extracted speech signal with at least one corresponding envelope property from the at least one extracted noise signal.

20. A method of detecting speech as in claim 12 further comprising dividing the at least one extracted speech signal in time into a plurality of windows, the speech detector generating a detected speech signal based on determining whether or not speech is present in each window.

21. A method of detecting speech as in claim 20 further comprising dividing the at least one extracted speech signal into a plurality of frequency bands, wherein generating a detected speech signal comprises determining whether or not speech is present in each frequency band.

22. A method of detecting speech as in claim 21 wherein generating the detected speech signal further comprises combining the determination for each frequency band for each window.

23. A method of detecting speech as in claim 12 further comprising determining a coding rate based on a determined presence of speech in the detected speech signal.

24. A method of detecting speech as in claim 12 further comprising determining a compression rate based on a determined presence of speech in the detected speech signal.

25. A method of detecting speech as in claim 12 wherein generating the detected speech signal comprises comparing at least one property of the extracted speech signal with at least one corresponding property of the at least one extracted noise signal.

27. A method of detecting speech as in claim 26 wherein extracting at least one noise parameter comprises time windowing the received at least one noise signal and wherein extracting at least one speech parameter comprises time windowing the received at least one speech signal.

28. A method of detecting speech as in claim 27 wherein extracting at least one noise parameter comprises dividing the windowed at least one noise signal into a first plurality of frequency bands and wherein extracting at least one speech parameter comprises dividing the at least one windowed speech signal into second plurality of frequency bands.

29. A method of detecting speech as in claim 28 wherein comparing comprises comparing each noise signal frequency band with a corresponding speech signal frequency band.

30. A method of detecting speech as in claim 29 wherein detecting the presence of speech comprises detecting the presence of speech for each frequency band.

12. A method of detecting speech in the presence of noise comprising:

receiving at least one signal containing speech mixed with noise;

extracting at least one extracted speech signal from the at least one received signal;

extracting at least one extracted noise signal from the at least one received signal; and

generating a detected speech signal based on the at least one extracted speech signal and the at least one extracted noise signal.

26. A method of detecting speech comprising:

receiving at least one noise signal;

receiving at least one speech signal having a greater content of the speech than the at least one noise signal;

extracting at least one noise parameter from the at least one noise signal;

extracting at least one speech parameter from the at least one speech signal;

comparing the at least one speech parameter and the at least one noise parameter; and

detecting the presence of speech based on the comparison.

31. A method of detecting speech comprising:

receiving a noise signal;

receiving a speech signal having greater speech content than the noise signal;

dividing the speech signal into a plurality of speech frequency bands;

dividing the noise signal into a plurality of noise frequency bands, each noise frequency band corresponding to one of the speech frequency bands;

for each speech frequency band, calculating at least one detection parameter based on at least one property of the speech frequency band and on at least one property of the corresponding noise frequency band;

for each speech frequency band, generating a frequency band output based on the at least one detection parameter for the speech frequency band.

32. A method of detecting speech as in claim 31 wherein the at least one property of the speech frequency band comprises speech power in the speech frequency band and wherein the at least one property of the noise frequency band comprises noise power in the noise frequency band.

33. A method of detecting speech as in claim 32 wherein calculating at least one detection parameter for each speech frequency band comprises calculating a ratio of speech power in the speech frequency band to noise power in the corresponding noise frequency band.

34. A method of detecting speech as in claim 31 wherein generating a frequency band output comprises attenuating the speech frequency band based on the at least one detection parameter for the speech frequency band.

35. A method of detecting speech as in claim 31 further comprising combining the frequency band output for each speech frequency band.