Utilizing digital microphones for low power keyword detection and noise suppression

• US 10,469,967 B2
• Filed: 07/23/2018
• Issued: 11/05/2019
• Est. Priority Date: 01/07/2015
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Knowles Electronics Incorporated (Knowles Corporation)
• Inventors: Rossum, David P., Warren, Niel D.
• Primary Examiner(s): Kim, Paul
• Application Number:
  US16/043,105
• Publication Number:
  US 20180332416A1
• Time in Patent Office: 470 Days
• Field of Search: 381 97, 381122
• CPC Class Codes: G10L 2015/088 Word spotting
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: H04R 2410/01 Noise reduction using microphones having different directional characteristics
• CPC Class Codes: H04R 2410/05 Noise reduction with a separate noise microphone
• CPC Class Codes: H04R 29/004 for microphones H04R29/007 takes precedence
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

Provided are systems and methods for utilizing digital microphones in low power keyword detection and noise suppression. An example method includes receiving a first acoustic signal representing at least one sound captured by a digital microphone. The first acoustic signal includes buffered data transmitted with a first clock frequency. The digital microphone may provide voice activity detection. The example method also includes receiving at least one second acoustic signal representing the at least one sound captured by a second microphone, the at least one second acoustic signal including real-time data. The first and second acoustic signals are provided to an audio processing system which may include noise suppression and keyword detection. The buffered portion may be sent with a higher, second clock frequency to eliminate a delay of the first acoustic signal from the second acoustic signal. Providing the signals may also include delaying the second acoustic signal.

Claims

1. An audio processor comprising:

a processor; and

memory communicatively coupled with the processor, the memory storing instructions which, when executed by the processor, configure the processor to;

receive a first signal representing at least one sound captured by a digital microphone, the first signal including buffered data;

receive at least one second signal representing the at least one sound captured by at least one second microphone, the at least one second signal including real-time data, the at least one second microphone being the digital microphone or a different microphone;

the buffered data delayed relative to the real-time data; and

process the first signal and the at least one second signal.

2. The processor of claim 1, wherein the at least one second microphone is the digital microphone, and wherein the instructions, when executed by the processor, configure the processor to prepend the buffered data to the real time data.

3. The processor of claim 2, wherein the first signal includes the buffered data received on a first channel and real time data received from the digital microphone on a second channel.

4. The processor of claim 2, wherein the instructions, when executed by the processor, configure the processor to perform noise suppression or word detection on the first signal and the at least one second signal after prepending.

5. The processor of claim 2, wherein the instructions, when executed by the processor, configure the processor to provide a clock signal in response to receiving an indication that voice activity has been detected by the digital microphone, wherein at least the real time data is received at a clock frequency of the clock signal provided by the processor.

6. The processor of claim 5, wherein the instructions, when executed by the processor, configure the processor to convert a sample rate of the buffered data to a sample rate corresponding to the clock signal provided by the processor.

7. The processor of claim 1, wherein the instructions, when executed by the processor, configure the processor to provide a clock signal to the digital microphone after receiving an indication that voice activity has been detected by the digital microphone, wherein at least the buffered data is sampled at a frequency less than a frequency of the clock signal provided by the processor and the buffered data is received at the frequency of the clock signal provided by the processor.

8. The processor of claim 1, wherein the instructions, when executed by the processor, configure the processor to reduce latency between the first signal and the at least one second signal by delaying at least the first signal or the at least one second signal before processing.

9. A method in an audio processor, the method comprising:

receiving, at the audio processor, a first signal representing at least one sound captured by a digital microphone, the first signal including buffered data;

receiving, at the audio processor, at least one second signal representing the at least one sound captured by at least one second microphone, the at least one second signal including real-time data, the at least one second microphone being the digital microphone or a different microphone;

the buffered data delayed relative to the real-time data; and

processing the first signal and the at least one second signal at the audio processor.

10. The method of claim 9, wherein processing the first signal and the at least one second signal at the audio processor includes prepending the buffered data to the real time data.

11. The method of claim 10, wherein receiving the first signal includes receiving the buffered data from the digital microphone on a first channel and receiving real time data from the digital microphone on a second channel.

12. The method of claim 10, wherein processing includes performing noise suppression or key word detection on the first signal and the at least one second signal at the audio processor.

13. The method of claim 10 further comprising:

receiving, at the audio processor, an indication that voice activity has been detected by the digital microphone;

providing a clock signal from the audio processor after receiving the indication,

wherein at least the real time data from the digital microphone is received at a clock frequency of the clock signal provided by the audio processor.

14. The method of claim 13 further comprising converting the buffered data received from the digital microphone to a sample rate of the clock signal provided by the audio processor.

15. The method of claim 9 further comprising:

receiving, at the audio processor, an indication that voice activity has been detected by the digital microphone;

providing a clock signal from the audio processor to the digital microphone after receiving the indication,

wherein at least the buffered data received from the digital microphone is sampled at a frequency less than a frequency of the clock signal provided by the audio processor and the buffered data is transmitted at the frequency of the clock signal provided by the audio processor.

16. The method of claim 9 further comprising reducing latency between the first signal and the at least one second signal by delaying at least one of the first signal and the at least one second signal before processing.

17. An audio processing system comprising:

a digital microphone having a buffer and an internal clock, the digital microphone configured to capture sound and buffer data representative of the captured sound using the internal clock, and to transmit a first signal including the buffered data;

a second microphone configured to capture the sound and transmit a second signal representative of the captured sound, the second signal including real time data,

the buffered data delayed relative to the real-time data;

a processor communicatively coupled to memory storing instructions which, when executed by the processor, configure the processor to;

receive the first signal and the second signal;

prepend the buffered data to the real time data.

18. The system of claim 17, wherein the instructions, when executed by the processor, configure the processor to perform noise suppression or word detection on the first signal and the second signal.

19. The system of claim 17, the first signal including real time data, the digital microphone configured to transmit the buffered data on a first channel and the real time data on a second channel.

20. The system of claim 17, wherein the instructions, when executed by the processor, configure the processor to provide a clock signal to the digital microphone after receiving an indication that voice activity has been detected by the digital microphone, wherein at least the buffered data received from the digital microphone is sampled at a frequency less than a frequency of the clock signal provided by the audio processor and wherein the digital microphone transmits the buffered data at the frequency of the clock signal provided by the processor.