Ambient noise cancellation for voice communication device

• US 9,369,799 B2
• Filed: 06/24/2013
• Issued: 06/14/2016
• Est. Priority Date: 03/21/2002
• Status: Expired due to Term

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Hartselle, William A., Short, Shannon M., Meadows, Vernon
• Primary Examiner(s): Paul, Disler
• Application Number:
  US13/924,733
• Publication Number:
  US 20130287220A1
• Time in Patent Office: 1,086 Days
• Field of Search: 381 941- 949, 381 711- 719, 381 7111- 7113, 704/226, 704/233
• US Class Current: 1/1
• CPC Class Codes: G10K 11/17821 characterised by the analysis of the input signals only
• CPC Class Codes: G10K 11/1783 handling or detecting of non-standard events or conditions, e.g. changing operating modes under specific operating conditions
• CPC Class Codes: G10K 11/17857 Geometric disposition, e.g. placement of microphones
• CPC Class Codes: G10K 11/17873 using a reference signal without an error signal, e.g. pure feedforward
• CPC Class Codes: G10K 11/17885 additionally using a desired external signal, e.g. pass-through audio such as music or speech
• CPC Class Codes: G10K 2210/1081 Earphones, e.g. for telephones, ear protectors or headsets
• CPC Class Codes: G10K 2210/3036 Modes, e.g. vibrational or spatial modes
• CPC Class Codes: G10K 2210/3045 Multiple acoustic inputs, single acoustic output
• CPC Class Codes: H04M 1/6008 in the transmitter circuit
• CPC Class Codes: H04R 3/002 Damping circuit arrangements for transducers, e.g. motional feedback circuits
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A system and method for reducing or entirely canceling background or ambient noise from a voice transmission from a communications device. A communications device, such as a mobile telephone, is configured with an ambient noise compensation signal generator that is connected between a microphone and a mixer. The original output of the microphone and a compensation signal generated by the ambient noise compensation signal generator are mixed together prior to being passed to a transmitter. In one embodiment a buffer is provided between the microphone and the mixer to help synchronize the timing of the signals to be mixed. In another embodiment a second microphone is employed to detect ambient noise.

Claims

1. A method, comprising:

detecting, by a first microphone, a first signal containing voice signals and ambient noise;

detecting, by a second microphone, a second signal containing the ambient noise;

receiving a noise cancellation signal indicating whether to cancel the ambient noise;

providing both the first signal detected by the first microphone and the second signal detected by the second microphone to an ambient noise compensation signal generator;

responsive to the noise cancellation signal indicating to cancel the ambient noise, enabling an ambient noise compensation signal generator to generate the compensation signal based on the first signal detected by the first microphone and the second signal detected by the second microphone, wherein a mixer mixes the first signal detected by the first microphone with the compensation signal such that the ambient noise contained in the first signal detected by the first microphone is attenuated; and

responsive to the noise cancellation signal indicating not to cancel the ambient noise, disabling the ambient noise compensation signal generator, wherein the mixer mixes the first signal detected by the first microphone with the second signal detected by the second microphone, such that the ambient noise contained in the first signal detected by the first microphone is not attenuated.

2. The method of claim 1, further comprising providing an output of the mixer to a transmitter.

3. The method of claim 1, wherein the first microphone is a directional microphone that is sensitive to sound coming from a predetermined direction, such that voice signals are predominantly received by the first microphone.

4. The method of claim 1, wherein the second microphone is an omnidirectional microphone that is substantially equally sensitive to sound emanating from any direction, such that voice signals and ambient noise are received by the second microphone.

5. The method of claim 1, wherein the second microphone is spatially distant from the first microphone.

6. The method of claim 1, further comprising buffering the first signal such that an arrival time of the first signal and the compensation signal at the mixer is synchronized.