System and method for adaptive classification of audio sources

• US 8,143,620 B1
• Filed: 12/21/2007
• Issued: 03/27/2012
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Audience Corporation
• Inventors: Malinowski, Stephen, Avendano, Carlos
• Primary Examiner(s): Tran, Tan N
• Application Number:
  US12/004,897
• Time in Patent Office: 1,558 Days
• Field of Search: 381/94.3, 381/94.2, 381/94.1, 381/92, 381/98, 381/73.1, 381/57, 381/56
• US Class Current: 257/56
• CPC Class Codes: H04R 2430/03 Synergistic effects of band splitting and sub-band processing
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04S 2420/01 Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD]

Abstract

Systems and methods for adaptively classifying audio sources are provided. In exemplary embodiments, at least one acoustic signal is received. One or more acoustic features based on the at least one acoustic signal are derived. A global summary of acoustic features based, at least in part, on the derived one or more acoustic features is determined. Further, an instantaneous global classification based on a global running estimate and the global summary of acoustic features is determined. The global running estimates may be updated and an instantaneous local classification based, at least in part, on the one or more acoustic features may be derived. One or more spectral energy classifications based, at least in part, on the instantaneous local classification and the one or more acoustic features may be determined. In some embodiments, the spectral energy classification is provided to a noise suppression system.

Claims

1. A method for processing acoustic signals, comprising:

receiving at least one acoustic signal;

deriving one or more acoustic features based on the at least one acoustic signal;

determining a global summary of acoustic features based, at least in part, on the derived one or more acoustic features;

determining an instantaneous global classification based on a global running estimate and the global summary of acoustic features;

updating the global running estimates;

deriving an instantaneous local classification based on at least the one or more acoustic features;

determining one or more spectral energy classifications based, at least in part, on the instantaneous local classification and the one or more acoustic features; and

providing the spectral energy classification.

2. The method of claim 1 wherein the one or more acoustic features are frequency specific.

3. The method of claim 1 wherein the one or more acoustic features comprises an inter-microphone level difference between a primary acoustic signal and a secondary acoustic signal of the at least one acoustic signal.

4. The method of claim 1 wherein the one or more acoustic features comprises a time difference within the at least one acoustic signal.

5. The method of claim 1 further comprising calculating a noise power spectrum based on the spectral energy classification.

6. The method of claim 5 further comprising generating an adaptive gain mask based on the noise power spectrum.

7. The method of claim 6 further comprising applying the adaptive gain mask to the primary acoustic signal.

8. The method of claim 1 further comprising generating and applying a comfort noise to a noise suppressed signal prior to output.

9. The method of claim 1 wherein determining the global summary of acoustic features comprises summing weighted local inter-microphone level differences.

10. The method of claim 1 wherein determining an instantaneous global classification comprises comparing the global summary of acoustic features to the global running estimates and classifying with respect to which global running estimate is closest to the global summary of acoustic features.

11. A non-transitory computer-readable storage medium having embodied thereon a program, the program providing instructions executable by a processor for processing acoustic signals, the method comprising:

receiving at least one acoustic signal;

deriving one or more acoustic features based on the at least one acoustic signal;

determining a global summary of acoustic features based, at least in part, on the derived one or more acoustic features;

determining an instantaneous global classification based on a global running estimate and the global summary of acoustic features;

updating the global running estimates;

deriving an instantaneous local classification based on at least the one or more acoustic features;

determining one or more spectral energy classifications based, at least in part, on the instantaneous local classification and the one or more acoustic features; and

providing the spectral energy classification.

12. The non-transitory computer-readable storage medium of claim 11 wherein the one or more acoustic features are frequency specific.

13. The non-transitory computer-readable storage medium of claim 11 wherein determining the global summary of acoustic features comprises summing weighted local inter-microphone level differences.

14. The non-transitory computer-readable storage medium of claim 11 wherein determining an instantaneous global classification comprises comparing the global summary of acoustic features to the global running estimates and classifying with respect to which global running estimate is closest to the global summary of acoustic features.