Method and Device for Acoustic Management Control of Multiple Microphones

• US 20090016542A1
• Filed: 06/09/2008
• Published: 01/15/2009
• Est. Priority Date: 05/04/2007
• Status: Active Grant

• Current Assignee: Cases2Tech, LLC
• Original Assignee: Personics Holdings, Inc.
• Inventors: Goldstein, Steve Wayne, Usher, John, Mclntosh, Jason, Boillot, Marc Andre
• Granted Patent: US 8,315,400 B2
• Time in Patent Office: Days
• US Class Current: 381/57
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

An earpiece (100) and a method (640) for acoustic management of multiple microphones is provided. The method can include capturing an ambient acoustic signal from an Ambient Sound Microphone (ASM) to produce an electronic ambient signal, capturing in an ear canal an internal sound from an Ear Canal Microphone (ECM) to produce an electronic internal signal, measuring a background noise signal, and mixing the electronic ambient signal with the electronic internal signal in a ratio dependent on the background noise signal to produce a mixed signal. The mixing can adjust an internal gain of the electronic internal signal and an external gain of the electronic ambient signal based on the background noise characteristics. The mixing can account for an acoustic attenuation level and an audio content level of the earpiece. Other embodiments are provided.

Claims

1. An earpiece comprising:

at least one Ambient Sound Microphone (ASM) configured to convert an ambient sound to an ambient sound signal;

at least one Ear Canal Microphone (ECM) configured to convert an internal sound from an ear canal of a user to an internal sound signal and where the internal sound signal includes an internal voice of the user; and

a processor operatively coupled to the at least one ECM and receives the internal sound signal from the at least one ECM, where the processor is operatively coupled to the at least one ASM and receives the ambient sound signal from the at least one ASM, and where the processor is configured to filter the internal sound signal based on characteristics of the ambient sound signal.

2. The earpiece of claim 1 further including an Ear Canal Receiver (ECR) for delivering audio content to the ear canal of the user where user speech delivered by the ECR is filtered to provide a natural sounding voice to the user.

3. The earpiece of claim 1 where the ambient sound signal includes an external voice signal, where the ambient sound signal and the internal sound signal are mixed to form a mixed signal, and where the mixed signal is provided to the ECR.

4. The earpiece of claim 3 where the mixing of the ambient sound signal and the internal sound signal is a ratio dependent on the characteristics of a background noise level of the ambient sound signal.

5. The earpiece of claim 4 where at low background noise levels the ambient sound signal from the ASM is amplified relative to the internal sound signal from the ECM, where at medium background noise level the low frequencies of the ambient sound signal are attenuated and the high frequencies of the internal sound signal are attenuated, and where at high background noise levels the internal sound signal from the ECM is amplified relative to the ambient sound signal from the ASM.

6. The earpiece of claim 1 where the characteristics of the ambient sound signal for selecting a filter characteristic is a level of the background noise level.

7. The earpiece of claim 1 where the characteristics of the ambient sound signal for selecting a filter characteristic is a spectral profile.

8. The earpiece of claim 1 where the characteristics of the ambient sound signal for selecting a filter characteristic is an envelope fluctuation.

9. The earpiece of claim 1 where an analog circuit is used to filter the ambient sound signal or the internal sound signal.

10. The earpiece of claim 1 where a time domain transversal filter is used to filter the ambient sound signal or the internal sound signal.

11. The earpiece of claim 1 where an IIR-type filter is used to filter the ambient sound signal or the internal sound signal.

12. The earpiece of claim 1 where frequency-domain multiplication is used to filter the ambient sound signal or the internal sound signal.

13. The earpiece of claim 1 where an adaptive filter is used to filter the ambient sound signal or the internal sound signal.

19. The method of claim 1, where the step of filtering further includes filtering the ambient sound signal and the internal sound signal based on characteristics of the background noise signal where the characteristic is a level of the background noise level, a spectral profile, or an envelope fluctuation.

14. A method comprising the steps of:

providing an acoustic barrier to an ear canal of a user;

capturing an ambient acoustic signal from at least one Ambient Sound Microphone (ASM) to produce an ambient sound signal that includes an external voice signal of the user;

capturing in the ear canal of the user an internal sound from the at least one Ear Canal Microphone (ECM) to produce an internal sound signal that includes an internal voice signal of the user; and

filtering the internal sound signal based on characteristics of the ambient sound signal.

15. The method of claim 14 further including a step of measuring a background noise signal of the ambient sound signal.

16. The method of claim 15 further including a step of filtering the ambient sound signal and the internal sound signal based on the characteristics of the background noise signal.

17. The method of claim 16 further including a step of mixing the ambient sound signal and the internal sound signal in a ratio dependent on the background noise signal to produce a mixed signal.

18. The method of claim 17 further including:

decreasing an internal gain of the internal sound signal as background noise levels decrease, while

increasing an external gain of the ambient sound signal as the background noise levels decreases.

20. An earpiece comprising:

a sealing section in an ear canal of a user;

at least one Ambient Sound Microphone (ASM) configured to convert an ambient sound to an ambient sound signal and where the ambient sound signal includes an external voice signal of the user;

at least one Ear Canal Microphone (ECM) configured to convert an internal sound from the ear canal of the user to an internal sound signal and where the internal sound signal includes an internal voice signal of the user; and

a processor operatively coupled to the at least one ECM and receives the internal sound signal from the at least one ECM, where the processor is operatively coupled to the at least one ASM and receives the ambient sound signal from the at least one ASM, where the processor is configured to filter the internal sound signal and the ambient sound signal based on characteristics of a background noise signal of the ambient sound signal; and

at least one Ear Canal Receiver (ECR) operatively coupled to the processor for receiving an output signal and configured to deliver audio content to the ear canal of the user.

21. The earpiece of claim 20 where the output signal comprises the ambient sound signal and the internal sound signal mixed as a function of the background noise signal.

22. The earpiece of claim 21 where the processor is configured to filter the ambient sound signal and the internal sound signal based on characteristics of the background signal where the characteristic is a level of the background noise level, a spectral profile, or an envelope fluctuation.