Multi-microphone system to support bandpass filtering for analog-to-digital conversions at different data rates

• US 8,964,966 B2
• Filed: 09/15/2010
• Issued: 02/24/2015
• Est. Priority Date: 09/15/2010
• Status: Expired due to Fees

• Current Assignee: Avaya Incorporated
• Original Assignee: Avaya Incorporated
• Inventors: Michaelis, Paul Roller
• Primary Examiner(s): Jamal, Alexander
• Application Number:
  US12/882,929
• Publication Number:
  US 20120063587A1
• Time in Patent Office: 1,623 Days
• Field of Search: 37938701-397, 379/93.06, 379/93.08, 379/399.02, 379/422
• US Class Current: 379/399.02
• CPC Class Codes: H04M 1/253 Telephone sets using digital voice transmission
• CPC Class Codes: H04M 11/066 Telephone sets adapted for data transmision
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

One exemplary problem addressed by the techniques disclosed herein is that the A-to-D converter of the broad-band audio codec that is being used more frequently in IP telephony, G.722, samples the analog audio source 16,000 times per second, rather than 8,000. Since all G.722-capable telephones must continue to be G.711-capable, one problem is that a microphone that provides appropriate bandpass filtering for G.722 encoding fails to provide adequate filtering for G.711. One exemplary aspect is therefore directed to telephones that must be able to switch back and forth between narrow-band digital audio encoding in which the A-to-D converter samples the audio stream 8,000 times per second, and a wide-band audio encoding in which the A-to-D converter samples the audio stream 16,000 times per second. This is accomplished using one or more of a plurality of switched microphones, a filter and a modification of the resonant frequencies of a handset.

Claims

1. A method of selecting a bandpass filtering technique for a device that supports more than one analog to digital conversion rate comprising:

detecting information indicative of whether wide-band or narrow-band encoding is required to support an underlying telephony communication; and

selecting a specific microphone from a plurality of microphones comprising a wide-band microphone and a narrow-band microphone, based on the detecting step, and wherein the wide-band microphone is selected as the specific microphone upon the detecting step indicating wide-band encoding is required and the narrow-band microphone is selected as the specific microphone upon the detecting step indicating narrow-band encoding is required.

2. The method of claim 1, further comprising forwarding input from the selected specific microphone to an analog to digital converter.

3. The method of claim 1, further comprising engaging a switch to select the specific microphone from the plurality of microphones.

4. The method of claim 1, wherein the information is one or more of a handshake, a SIP handshake, a narrow-band request, a wide-band request and an audio encoding request.

5. The method of claim 1, wherein the detecting step comprises detecting far-end equipment capabilities.

6. The method of claim 1, wherein the detecting step further comprising detecting one or more channel conditions.

7. The method of claim 1, wherein the device is a communications device.

8. The method of claim 1, wherein the device is a phone.

9. The method of claim 1, wherein the device is a microphone.

10. A system for selecting a bandpass filtering technique for a device that supports more than one analog to digital conversion rate comprising:

means for detecting information indicative of whether wide-band or narrow-band encoding is required to support the underlying telephony communication; and

means for selecting a specific microphone from a plurality of microphones comprising a wide-band microphone and a narrow-band microphone, based on the detecting step, and wherein the wide-band microphone is selected as the specific microphone upon the detecting means indicating wide-band encoding is required and the narrow-band microphone is selected as the specific microphone upon the detecting means indicating narrow-band encoding is required.

11. A system that selects a bandpass filtering technique for a device that supports more than one analog to digital conversion rate comprising:

a detection module that detects information indicative of whether wide-band or narrow-band encoding is required to support the underlying telephony communication; and

a switch that selects a specific microphone from a plurality of microphones comprising a wide-band microphone and a narrow band microphone based on the detecting step, and wherein the wide-band microphone is selected as the specific microphone upon the detecting module detecting wide-band encoding is required and the narrow-band microphone is selected as the specific microphone upon the detecting module detecting narrow-band encoding is required.

12. The system of claim 11, wherein input from the selected specific microphone is forwarded to an analog to digital converter.

13. The system of claim 11, further comprising a switch that selects the specific microphone from a plurality of wide-band microphones and a plurality of narrow-band microphones.

14. The system of claim 11, wherein the information is one or more of a handshake, a SIP handshake, a narrow-band request, a wide-band request and an audio encoding request.

15. The system of claim 11, wherein the detection module further detects far-end equipment capabilities.

16. The system of claim 11, wherein the detection module further detects one or more channel conditions.

17. The system of claim 11, wherein the device is a communications device.

18. The system of claim 11, wherein the device is a phone.

19. The system of claim 11, wherein the device is a microphone.

20. The system of claim 11, wherein the switch is operable to select the specific microphone further comprises the switch being further operable to select a plurality of specific microphones selected from a first plurality of narrow-band microphones and a second plurality of wide-band microphones.