Sound processing apparatus and recording medium storing a sound processing program

• US 9,747,919 B2
• Filed: 12/13/2011
• Issued: 08/29/2017
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Matsuo, Naoshi
• Primary Examiner(s): MONIKANG, GEORGE C
• Application Number:
  US13/324,297
• Publication Number:
  US 20120155674A1
• Time in Patent Office: 2,086 Days
• Field of Search: 381 92, 381 941- 943, 381 947
• 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 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 5/00 Stereophonic arrangements stereophonic pick-ups H04R9/16, H04R11/12, H04R17/08, H04R19/10

Abstract

A sound processing apparatus includes a first calculator that calculates first power based on a first signal received by a first microphone that is among the first microphone and a second microphone; a second calculator that calculates second power based on a second signal received by the second microphone; a gain calculator that calculates a gain on the basis of the ratio of the first power to the second power; and a multiplier that processes the second signal using the gain calculated by the gain calculator.

Claims

1. A sound processing apparatus comprising:

a memory; and

a processor coupled to the memory and configured to;

receive a first signal from a first microphone and a second signal from a second microphone;

process a first synchronous subtraction based on a first sample of the first signal and a second sample of the second signal;

process a second synchronous subtraction based on a first sample of the second signal and a second sample of the first signal;

calculate a first power based on a result of the first synchronous subtraction;

calculate a second power based on at a result of the second synchronous subtraction;

calculate a first gain based on the first power and a difference between the first power and the second power;

smooth the first gain;

process a combined result by multiplying the first synchronous subtraction by the smoothed first gain; and

output the combined result.

2. The sound processing apparatus according to claim 1, wherein the first microphone and the second microphone are omnidirectional microphones.

3. The sound processing apparatus according to claim 1, wherein the first synchronous subtraction is calculated by subtracting the second signal from the first signal in synchronization with a certain interval between a first input of a sound into the first microphone and a second input of the sound into the second microphone.

4. The sound processing apparatus according to claim 1, wherein the second synchronous subtraction is calculated by subtracting the first signal from the second signal in synchronization with a certain interval between a first input of a sound into the first microphone and a second input of the sound into the second microphone.

5. The sound processing apparatus according to claim 1, wherein the first microphone picks up a target sound, and the sound microphone picks up a noise prior to the target sound.

6. A sound processing method comprising:

receiving a first signal from a first microphone and a second signal from a second microphone;

processing, by circuitry, a first synchronous subtraction based on a first sample of the first signal and a second sample of the second signal;

processing, by the circuitry, a second synchronous subtraction based on a first sample of the second signal and a second sample of the first signal;

calculating, by the circuitry, a first power based on a result of the first synchronous subtraction;

calculating, by the circuitry, a second power based on a result of the second synchronous subtraction;

calculating, by the circuitry, a first gain based on the first power and a difference between the first power and the second power;

smoothing, by the circuitry, the first gain;

processing, by the circuitry, a combined result by multiplying the first synchronous subtraction by the smoothed first gain; and

outputting, by the circuitry, the combined result.

7. The sound processing method according to claim 6, wherein the first microphone and the second microphone are omnidirectional microphones.

8. The sound processing method according to claim 6, wherein the first synchronous subtraction is calculated by subtracting the second signal from the first signal in synchronization with a certain interval between a first input of a sound into the first microphone and a second input of the sound into the second microphone.

9. The sound processing method according to claim 6, wherein the second synchronous subtraction is calculated by subtracting the first signal from the second signal in synchronization with a certain interval between a first input of a sound into the first microphone and a second input of the sound into the second microphone.

10. The sound processing method according to claim 6, wherein the first microphone picks up a target sound, and the sound microphone picks up a noise prior to the target sound.

11. A non-transitory computer readable medium having a computer program recorded thereon, the computer program configured to perform a method when executed on a computer, the method comprising:

receiving a first signal from a first microphone and a second signal from a second microphone;

processing a first synchronous subtraction based on a first sample of the first signal and a second sample of the second signal;

processing a second synchronous subtraction based on a first sample of the second signal and a second sample of the first signal;

calculating a first power based on a result of the first synchronous subtraction;

calculating a second power based on a result of the second synchronous subtraction;

calculating a first gain based on the first power and a difference between the first power and the second power;

smoothing the first gain;

processing a combined result by multiplying the first synchronous subtraction by the smoothed first gain; and

outputting the combined result.

12. The non-transitory computer readable medium according to claim 11, wherein the first microphone and the second microphone are omnidirectional microphones.

13. The non-transitory computer readable medium according to claim 11, wherein the first synchronous subtraction is calculated by subtracting the second signal from the first signal in synchronization with a certain interval between a first input of a sound into the first microphone and a second input of the sound into the second microphone.

14. The non-transitory computer readable medium according to claim 11, wherein the second synchronous subtraction is calculated by subtracting the first signal from the second signal in synchronization with a certain interval between a first input of a sound into the first microphone and a second input of the sound into the second microphone.

15. The non-transitory computer readable medium according to claim 11, wherein the first microphone picks up a target sound, and the sound microphone picks up a noise prior to the target sound.