Apparatus with dynamic audio signal pre-conditioning and methods therefor

• US 9,237,225 B2
• Filed: 07/31/2013
• Issued: 01/12/2016
• Est. Priority Date: 03/12/2013
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Inventors: Garcia, Juan C, Clark, Joel A, Ramabadran, Tenkasi V
• Primary Examiner(s): Tsang, Fan
• Assistant Examiner(s): LYTLE, JEFFREY P
• Application Number:
  US13/955,198
• Publication Number:
  US 20140270150A1
• Time in Patent Office: 895 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G10L 2021/02082 the noise being echo, reverberation of the speech
• CPC Class Codes: G10L 21/02 Speech enhancement, e.g. noise reduction or echo cancellation reducing echo effects in line transmission systems H04B3/20; echo suppression in hands-free telephones H04M9/08
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: G10L 25/48 specially adapted for particular use
• CPC Class Codes: H04B 3/234 using double talk detection
• CPC Class Codes: H04M 3/002 Applications of echo suppressors or cancellers in telephonic connections in two-way loud-speaking telephone systems H04M9/08, echo suppressors or cancellers per se H04B3/20
• CPC Class Codes: H04M 9/082 using echo cancellers echo cancellers per se H04B3/23

Abstract

An apparatus includes an echo canceller having an audio signal input and an audio signal output and dynamic pre-conditioning logic. The dynamic pre-conditioning logic is operatively coupled to the echo canceller audio signal output as a feedback signal and has a dynamic pre-conditioning logic output operatively coupled to the echo canceller audio signal input. The dynamic pre-conditioning logic is also operative to receive an audio signal input from at least one microphone. The dynamic pre-conditioning logic is operative to analyze the feedback signal to obtain at least one characteristic, and pre-condition the audio signal input, based on the at least one characteristic of the feedback signal, and provide a pre-conditioned audio signal at the echo canceller audio signal input. The echo canceller audio signal output is then provided to a noise suppressor for the send path of a full duplex communication channel.

Claims

1. A computer-implemented method comprising:

receiving, by a dynamic pre-conditioning module that is communicatively coupled between a fixed pre-conditioning module and an echo cancelling module in a send path of a mobile communications device, an input audio signal from the fixed pre-conditioning module;

preconditioning, by the dynamic pre-conditioning module, the initial input audio based on one or more initial pre-conditioning parameters;

providing, by the dynamic pre-conditioning module, the preconditioned, initial input audio signal to the echo cancelling module;

receiving, by the dynamic pre-conditioning module, a subsequent input audio signal from the fixed pre-conditioning module;

receiving, by the dynamic pre-conditioning module, a feedback signal from the echo cancelling module to which the pre-conditioned, initial audio signal was provided;

determining, by the dynamic pre-conditioning module, one or more characteristics of the feedback signal from the echo cancelling module to which the preconditioned, initial audio signal was provided;

selecting, by the dynamic pre-conditioning module, one or more adjusted pre-conditioning parameters based on the one or more characteristics of the feedback signal;

pre-conditioning, by the dynamic pre-conditioning module, the subsequent input audio signal based on the one or more adjusted preconditioning parameters; and

providing, by the dynamic pre-conditioning module, the pre-conditioned, subsequent input audio signal to the echo cancelling module.

2. The method of claim 1, comprising:

providing a pre-conditioned echo cancelling audio signal output, based on the pre-conditioned, subsequent input audio signal, as a noise suppressor input; and

performing noise suppression on the noise suppressor input.

3. The method of claim 1, wherein determining one or more characteristics of the feedback signal comprises:

determining one or more frequency or amplitude characteristics of the feedback signal.

4. The method of claim 1, wherein determining one or more characteristics of the feedback signal comprises:

performing a Fast Fourier Transform (FFT) on the feedback signal.

5. The method of claim 4, wherein determining one or more characteristics of the feedback signal comprises:

determining whether noise contained in the feedback signal is below a cutoff frequency;

or

determining whether a near talker'"'"'s voice contained in the feedback signal is within a given frequency range.

6. The method of claim 4, comprising:

determining processing time available to perform filtering of the audio signal; and

selecting audio signal filters based on the processing time available.

7. The method of claim 1, comprising:

disabling fixed pre-conditioner filtering, prior to pre-conditioning the subsequent input audio signal.

8. A system comprising:

one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising;

receiving, by a dynamic pre-conditioning module that is communicatively coupled between a fixed pre-conditioning module and an echo cancelling module in a send path of a mobile communications device, an input audio signal from the fixed pre-conditioning module;

preconditioning, by the dynamic pre-conditioning module, the initial input audio signal based on one or more initial pre-conditioning parameters;

providing, by the dynamic pre-conditioning module, the preconditioned, initial input audio signal to the echo cancelling module;

receiving, by the dynamic pre-conditioning module, a subsequent input audio signal from the fixed pre-conditioning module;

receiving, by the dynamic pre-conditioning module, a feedback signal from the echo cancelling module to which the pre-conditioned, initial audio signal was provided;

determining, by the dynamic pre-conditioning module, one or more characteristics of the feedback signal from the echo cancelling module to which the preconditioned, initial audio signal was provided;

selecting, by the dynamic pre-conditioning module, one or more adjusted pre-conditioning parameters based on the one or more characteristics of the feedback signal;

pre-conditioning, by the dynamic pre-conditioning module, the subsequent input audio signal based on the one or more adjusted preconditioning parameters; and

providing, by the dynamic pre-conditioning module, the pre-conditioned, subsequent input audio signal to the echo cancelling module.

9. The system of claim 8, wherein the operations further comprise:

providing a pre-conditioned echo cancelling audio signal output, based on the pre-conditioned, subsequent input audio signal, as a noise suppressor input; and

performing noise suppression on the noise suppressor input.

10. The system of claim 8, wherein determining one or more characteristics of the feedback signal comprises:

determining one or more frequency or amplitude characteristics of the feedback signal.

11. The system of claim 8, wherein determining one or more characteristics of the feedback signal comprises:

performing a Fast Fourier Transform (FFT) on the feedback signal.

12. The system of claim 11, wherein determining one or more characteristics of the feedback signal comprises:

determining whether noise contained in the feedback signal is below a cutoff frequency;

or

determining whether a near talker'"'"'s voice contained in the feedback signal is within a given frequency range.

13. The system of claim 11, wherein the operations further comprise:

determining processing time available to perform filtering of the audio signal; and

selecting audio signal filters based on the processing time available.

14. The system of claim 8, wherein the operations further comprise:

disabling fixed pre-conditioner filtering, prior to pre-conditioning the subsequent input audio signal.

15. A non-transitory computer-readable medium storing software comprising instructions executable by one or more computers which, upon such execution, cause the one or more computers to perform operations comprising:

receiving, by a dynamic pre-conditioning module that is communicatively coupled between a fixed pre-conditioning module and an echo cancelling module in a send path of a mobile communications device, an input audio signal from the fixed pre-conditioning module;

preconditioning, by the dynamic pre-conditioning module, the initial input audio signal based on one or more initial pre-conditioning parameters;

providing, by the dynamic pre-conditioning module, the preconditioned, initial input audio signal to the echo cancelling module;

receiving, by the dynamic pre-conditioning module, a subsequent input audio signal from the fixed pre-conditioning module;

receiving, by the dynamic pre-conditioning module, a feedback signal from the echo cancelling module to which the pre-conditioned, initial audio signal was provided;

determining, by the dynamic pre-conditioning module, one or more characteristics of the feedback signal from the echo cancelling module to which the preconditioned, initial audio signal was provided;

selecting, by the dynamic pre-conditioning module, one or more adjusted pre-conditioning parameters based on the one or more characteristics of the feedback signal;

pre-conditioning, by the dynamic pre-conditioning module, the subsequent input audio signal based on the one or more adjusted preconditioning parameters; and

providing, by the dynamic pre-conditioning module, the pre-conditioned, subsequent input audio signal to the echo cancelling module.

16. The medium of claim 15, wherein the operations further comprise:

providing a pre-conditioned echo cancelling audio signal output, based on the pre-conditioned, subsequent input audio signal, as a noise suppressor input; and

performing noise suppression on the noise suppressor input.

17. The medium of claim 15, wherein determining one or more characteristics of the feedback signal comprises:

determining one or more frequency or amplitude characteristics of the feedback signal.

18. The medium of claim 15, wherein determining one or more characteristics of the feedback signal comprises:

performing a Fast Fourier Transform (FFT) on the feedback signal.

19. The medium of claim 18, wherein determining one or more characteristics of the feedback signal comprises:

determining whether noise contained in the feedback signal is below a cutoff frequency;

or

determining whether a near talker'"'"'s voice contained in the feedback signal is within a given frequency range.

20. The system of claim 15, wherein the operations further comprise:

disabling fixed pre-conditioner filtering, prior to pre-conditioning the subsequent input audio signal.