Microphone noise suppression for computing device

• US 9,922,637 B2
• Filed: 07/11/2016
• Issued: 03/20/2018
• Est. Priority Date: 07/11/2016
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Qiao, Tianzhu
• Primary Examiner(s): Sniezek, Andrew L
• Application Number:
  US15/207,317
• Publication Number:
  US 20180012585A1
• Time in Patent Office: 617 Days
• CPC Class Codes: G10K 11/178 by electro-acoustically regenerating the original acoustic waves in anti-phase
• CPC Class Codes: G10K 2210/129 Vibration, e.g. instead of, or in addition to, acoustic noise
• CPC Class Codes: G10K 2210/3012 Algorithms
• CPC Class Codes: G10K 2210/3028 Filtering, e.g. Kalman filters or special analogue or digital filters
• CPC Class Codes: G10L 2021/02165 Two microphones, one receiving mainly the noise signal and the other one mainly the speech signal
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: G10L 21/0224 Processing in the time domain
• CPC Class Codes: H04R 1/20 Arrangements for obtaining desired frequency or directional characteristics for stereophonic purpose H04R5/00
• CPC Class Codes: H04R 2410/05 Noise reduction with a separate noise microphone
• CPC Class Codes: H04R 2499/15 Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A computing device with a microphone system is disclosed. The computing device includes a microphone system with an environment microphone and a noise microphone. The environment microphone picks up an environment microphone signal which includes (1) a desired signal component based on desired sound and (2) a noise component based on noise from a noise source. The noise microphone picks up a noise microphone signal based on the noise, and is configured such that contributions to the noise microphone signal from the desired sound, if present, are attenuated relative to the environment microphone. A controller receives and processes time samples from the noise microphone signal to yield a noise estimation of the noise component. The estimation is subtracted from the environment microphone signal to yield and end-user output.

Claims

1. A computing device with a microphone system, comprising:

an environment microphone configured to pick up an environment microphone signal that includes a desired signal component based on desired sound and a noise component based on noise from a noise source;

a noise microphone configured to pick up a noise microphone signal based on the noise from the noise source, where the noise microphone is configured such that contributions to the noise microphone signal from the desired sound, if present, are attenuated relative to such contributions to the environment microphone signal;

a controller having an adaptive filter configured to receive and process a plurality of time samples of the noise microphone signal to yield a noise estimation of the noise component, the controller being configured to dynamically update such reception and processing by dynamically selecting an order of the adaptive filter;

a summer configured to subtract the noise estimation from the environment microphone signal to yield an end-user output; and

an enclosure, where the environment microphone is outside of the enclosure and where the noise microphone is within the enclosure.

2. The computing device of claim 1, where the dynamic updating is based on feedback of the end-user output to the controller.

3. The computing device of claim 1, where the adaptive filter is configured to apply coefficients to each of the plurality of time samples of the noise microphone signal to yield the noise estimation, and where the dynamic updating includes updating of one or more of the coefficients.

4. The computing device of claim 3, where the coefficients are updated via a least mean squares mechanism.

5. The computing device of claim 3, where the coefficients are updated via a recursive least squares filter.

6. The computing device of claim 1, where the controller is configured to selectively enable and disable the dynamic updating of the adaptive filter in response to detecting a condition.

7. The computing device of claim 6, where the controller is configured to disable the dynamic updating of the adaptive filter in response to detecting the noise microphone signal being below a threshold.

8. The computing device of claim 1, where the controller is configured to perform the dynamic selection of the order of the adaptive filter in response to detecting that the noise microphone signal is above a threshold and the environment microphone signal is below a threshold.

9. The computing device of claim 1, where the controller is configured to disable noise estimation subtraction from the environment microphone signal in response to detecting a condition.

10. The computing device of claim 1, where the noise microphone has a directional configuration focused on a location of the noise source.

11. A method for processing sound received by a microphone system of a computing device, comprising:

receiving an environment microphone signal from an environment microphone outside of an enclosure of the computing device, the environment microphone signal including a desired signal component based on desired sound and a noise component based on noise from a noise source;

receiving a noise microphone signal from a noise microphone within the enclosure, the noise microphone being configured such that contributions to the noise microphone signal from the desired sound, if present, are attenuated relative to such contributions to the environment microphone signal;

using an adaptive filter to process a plurality of time samples of the noise microphone signal to yield a noise estimation of the noise component;

subtracting the noise estimation from the environment microphone signal to yield an end-user output; and

dynamically updating the adaptive filter to update the way in which it processes time samples of the noise microphone signal to yield the noise estimation, by dynamically selecting an order of the adaptive filter.

12. The method of claim 11, where using the adaptive filter to process the plurality of time samples of the noise microphone signal includes applying coefficients to each of the plurality of time samples, and where dynamically updating the adaptive filter further includes the coefficients being dynamically updated based on feedback of the end-user output to the adaptive filter.

13. The method of claim 11, further comprising disabling the dynamic updating of the adaptive filter in response to detecting that the noise microphone signal is below a threshold.

14. The method of claim 11, where dynamically selecting an order of the adaptive filter is done in response to detecting that the noise microphone signal is above a threshold and the environment microphone signal is below a threshold.

15. A computing device with a microphone system, comprising:

an environment microphone configured to pick up an environment microphone signal that includes a desired signal component based on desired sound and a noise component based on noise from a noise source;

a noise microphone configured to pick up a noise microphone signal based on the noise from the noise source, where the noise microphone is configured such that contributions to the noise microphone signal from the desired sound, if present, are attenuated relative to such contributions to the environment microphone signal;

a controller including an adaptive filter configured to receive and process a plurality of time samples of the noise microphone signal to yield a noise estimation of the noise component, the adaptive filter being configured to be dynamically updated in the way in which it processes time samples of the noise microphone signal to yield the noise estimation by dynamically selecting an order of the adaptive filter;

a summer configured to subtract the noise estimation from the environment microphone signal to yield an end-user output; and

an enclosure, where the environment microphone is outside of the enclosure and where the noise microphone is within the enclosure,

where the controller is configured to disable the dynamic updating of the adaptive filter in response to detecting the noise microphone signal is below a threshold.