Signal processing apparatus, signal processing method, and program

• US 9,277,318 B2
• Filed: 03/22/2012
• Issued: 03/01/2016
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sakai, Juri
• Primary Examiner(s): Zhang, Leshui
• Application Number:
  US13/427,272
• Publication Number:
  US 20120250900A1
• Time in Patent Office: 1,440 Days
• Field of Search: 381/122, 381/123, 381/119, 381/100, 381/97, 381/98, 381/92, 381/91, 381/94.9, 381/317, 381/56, 381/58, 381/26, 381/316, 381/318, 381/320, 381/321, 381/57, 381/60, 700/94
• US Class Current: 1/1
• CPC Class Codes: H04R 1/1083 Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06
• CPC Class Codes: H04R 2201/107 Monophonic and stereophonic headphones with microphone for two-way hands free communication
• CPC Class Codes: H04R 2410/05 Noise reduction with a separate noise microphone
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone
• CPC Class Codes: H04R 2460/01 Hearing devices using active noise cancellation
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 2499/15 Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops
• 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 3/04 for correcting frequency response

Abstract

A signal processing apparatus includes a filter that performs filtering of a correction filter characteristic including a reverse characteristic of an output characteristic of a microphone on a signal acquired by the microphone.

Claims

1. A signal processing apparatus comprising:

circuitry configured to

perform filtering of a correction filter characteristic including a reverse characteristic of an output characteristic of a microphone on a signal acquired by the microphone; and

selectively output the signal acquired by the microphone or an output signal that has been filtered in accordance with the correction filter characteristic,

wherein the correction filter characteristic is obtained by combining the reverse characteristic of the output characteristic of the microphone and a reverse characteristic of a sound characteristic based on at least one structure that diffracts or blocks a part of a sound wave from reaching a sound receiving face of the microphone, and wherein the acquired signal is acquired based on a part of the sound wave that is collected by the microphone.

2. The signal processing apparatus according to claim 1, wherein the correction filter characteristic has a constant group delay characteristic.

3. The signal processing apparatus according to claim 1, wherein the correction filter characteristic is the reverse characteristic of the output characteristic of the microphone.

4. The signal processing apparatus according to claim 1, wherein the correction filter characteristic is a characteristic obtained by combining the reverse characteristic of the output characteristic of the microphone and a predetermined sound characteristic.

5. The signal processing apparatus according to claim 4, wherein the predetermined sound characteristic is a sound characteristic of another microphone different from the microphone.

6. The signal processing apparatus according to claim 1, further comprising a filter characteristic switching unit that changes the correction filter characteristic, wherein a plurality of characteristics are provided as the correction filter characteristic.

7. The signal processing apparatus according to claim 1, wherein the filtering flattens a frequency characteristic of the microphone and makes linear a phase characteristic of the microphone.

8. A signal processing method being executed by a processor of a signal processing apparatus, the signal processing method comprising:

Performing, by the processor, filtering of a correction filter characteristic including a reverse characteristic of an output characteristic of a microphone on a signal acquired by the microphone; and

selectively outputting the signal acquired by the microphone or an output signal that has been filtered in accordance with the correction filter characteristic,

wherein the correction filter characteristic is obtained by combining the reverse characteristic of the output characteristic of the microphone and a reverse characteristic of a sound characteristic based on at least one structure that diffracts or blocks a part of a sound wave from reaching a sound receiving face of the microphone, and wherein the acquired signal is acquired based on a part of the sound wave that is collected by the microphone.

9. A non-transitory computer-readable medium having embodied thereon a program, which when executed by a processor causes the processor to perform a signal processing method, the signal processing method comprising:

initiating filtering of a correction filter characteristic including a reverse characteristic of an output characteristic of a microphone on a signal acquired by the microphone; and

selectively outputting the signal acquired by the microphone or an output signal that has been filtered in accordance with the correction filter characteristic,

wherein the correction filter characteristic is obtained by combining the reverse characteristic of the output characteristic of the microphone and a reverse characteristic of a sound characteristic based on at least one structure that diffracts or blocks a part of a sound wave from reaching a sound receiving face of the microphone, and wherein the acquired signal is acquired based on a part of the sound wave that is collected by the microphone.

10. A signal processing apparatus comprising;

circuitry configured to

form a plurality of signal processing units that process signals acquired by a plurality of microphones, wherein at least one of the plurality of signal processing units has a filter that performs filtering of a correction filter characteristic including a reverse characteristic of an output characteristic of a corresponding microphone of the plurality of microphones on a signal acquired by the corresponding microphone, and

selectively output the signal acquired by the corresponding microphone or an output signal that has been filtered in accordance with the correction filter characteristic,

wherein the correction filter characteristic is obtained by combining the reverse characteristic of the output characteristic of the corresponding microphone and a reverse characteristic of a sound characteristic based on at least one structure that diffracts or blocks a part of a sound wave from reaching a sound receiving face of the corresponding microphone, and wherein the acquired signals are acquired based on a part of the sound wave that is collected by the plurality of microphones.

11. The signal processing apparatus according to claim 10, wherein the filter is a filter having a constant group delay characteristic.

12. The signal processing apparatus according to claim 10, wherein the correction filter characteristic is a characteristic obtained by combining the reverse characteristic of the output characteristic of the corresponding microphone and a predetermined sound characteristic.

13. The signal processing apparatus according to claim 12, wherein the predetermined sound characteristic is a sound characteristic of the other microphone different from the corresponding microphone.