Dynamic gain adjustment based on signal to ambient noise level

• US 8,798,278 B2
• Filed: 03/30/2011
• Issued: 08/05/2014
• Est. Priority Date: 09/28/2010
• Status: Active Grant

• Current Assignee: Bose Corporation
• Original Assignee: Bose Corporation
• Inventors: Isabelle, Steven H., Iyengar, Vasu
• Primary Examiner(s): Nguyen, Duc
• Assistant Examiner(s): Le, Phan
• Application Number:
  US13/075,536
• Publication Number:
  US 20120076311A1
• Time in Patent Office: 1,224 Days
• Field of Search: 381/56, 381/57, 381/92, 381/94.1, 381/94.7, 381/95, 381/96
• US Class Current: 381/57
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: H04R 1/086 Protective screens, e.g. all weather or wind screens
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone

Abstract

Methods and apparatuses for deriving a signal-to-noise ratio based at least in part on a measured level of a signal carrying far-end speech, and a measured level of a signal carrying ambient acoustic noise; determining a target gain adjustment based at least in part on the derived signal-to-noise ratio; applying the target gain adjustment to the signal carrying far-end speech to produce a gain-adjusted signal; and providing the gain-adjusted signal for audio output from a communications device.

Claims

1. A method comprising:

deriving a signal-to-noise ratio based at least in part on a measured level of a signal carrying far-end speech, a measured level of a signal carrying ambient acoustic noise, and a user-selected gain adjustment provided via a user-operable gain controller;

determining a target gain adjustment based at least in part on the derived signal-to-noise ratio, and based at least in part on a mapping of signal-to-noise ratio to gain in which the mapping approaches a unity gain (0 dB) at high signal-to-noise ratios and has a negative slope of nonincreasing magnitude as the signal-to-noise ratios increase from low to high;

applying the target gain adjustment to the signal carrying far-end speech to produce a gain-adjusted signal; and

providing the gain-adjusted signal for audio output from a communications device.

2. The method of claim 1, wherein the communications device comprises a wireless in-ear headset.

3. The method of claim 1, wherein the user-operable gain controller is a component of the communications device.

4. The method of claim 1, wherein the mapping is expressed as a gain curve.

5. A communications device comprising:

a user-operable gain controller;

first circuitry operable to derive a signal-to-noise ratio based at least in part on a measured level of a signal carrying far-end speech, a measured level of a signal carrying ambient acoustic noise, and a user-selected gain adjustment provided via the user-operable gain controller;

second circuitry operable to determine a target gain adjustment based at least in part on the derived signal-to-noise ratio, and based at least in part on a mapping of signal-to-noise ratio to gain in which the mapping approaches a unity gain (0 dB) at high signal-to-noise ratios and has a negative slope of nonincreasing magnitude as the signal-to-noise ratios increase from low to high; and

third circuitry operable to apply the target gain adjustment to the signal carrying far-end speech to produce a gain-adjusted signal and provide the gain-adjusted signal for output from the device.

6. The device of claim 5, further comprising:

an electronics module to wirelessly receive audio signals carrying far-end speech and wirelessly transmit audio signals carrying near-end speech.

7. The device of claim 5, further comprising:

an audio module including an acoustic driver to transduce audio signals to acoustic energy.

8. The device of claim 5, wherein the device comprises an in-ear component that includes:

an outlet section dimensioned and arranged to fit inside an ear canal of a user; and

a passageway to conduct acoustic energy from an audio module to an opening in the outlet section.

9. The device of claim 5, further comprising:

an electronics module including a microphone having multiple acoustic ports.

10. The device of claim 9, wherein the microphone has two acoustic ports with a center-to-center spacing of approximately 6.5 mm.

11. The device of claim 9, further comprising:

a porous member arranged over the microphone to reduce wind noise.