NOISE REDUCTION APPARATUS, AUDIO INPUT APPARATUS, WIRELESS COMMUNICATION APPARATUS, AND NOISE REDUCTION METHOD

• US 20130073283A1
• Filed: 09/14/2012
• Published: 03/21/2013
• Est. Priority Date: 09/15/2011
• Status: Active Grant

• Current Assignee: SoundClear Technologies LLC
• Original Assignee: JVC Kenwood Corporation
• Inventors: YAMABE, Takaaki
• Granted Patent: US 9,031,259 B2
• Time in Patent Office: Days
• US Class Current: 704/226
• 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 21/0216 characterised by the method used for estimating noise

Abstract

It is determined whether or not a sound picked up by at least either a first microphone or a second microphone is a speech segment. When it is determined that the sound picked up by the first or the second microphone is the speech segment, a voice incoming direction indicating from which direction a voice sound travels is detected based on a first sound pick-up signal obtained based on a sound picked up by the first microphone and a second sound pick-up signal obtained based on a sound picked up by the second microphone. A noise reduction process is performed using the first and second sound pick-up signals based on speech segment information indicating that the sound picked up by the first or the second microphone is the speech segment and voice incoming-direction information indicating the voice incoming direction.

Claims

1. A noise reduction apparatus comprising:

a speech segment determiner configured to determine whether or not a sound picked up by at least either a first microphone or a second microphone is a speech segment and to output speech segment information when it is determined that the sound picked up by the first or the second microphone is the speech segment;

a voice direction detector configured, when receiving the speech segment information, to detect a voice incoming direction indicating from which direction a voice sound travels, based on a first sound pick-up signal obtained based on a sound picked up by the first microphone and a second sound pick-up signal obtained based on a sound picked up by the second microphone and to output voice incoming-direction information when the voice incoming direction is detected; and

an adaptive filter configured to perform a noise reduction process using the first and second sound pick-up signals based on the speech segment information and the voice incoming-direction information.

2. The noise reduction apparatus according to claim 1, wherein the voice direction detector detects the voice incoming direction based on a phase difference between the first and second sound pick-up signals.

3. The noise reduction apparatus according to claim 2, wherein the adaptive filter performs the noise reduction process to reduce a noise component carried by the first sound pick-up signal using the second sound pick-up signal when the first sound pick-up signal has a more advanced phase than the second sound pick-up signal whereas the adaptive filter performs the noise reduction process to reduce a noise component carried by the second sound pick-up signal using the first sound pick-up signal when the second sound pick-up signal has a more advanced phase than the first sound pick-up signal.

4. The noise reduction apparatus according to claim 2, wherein when the phase difference is within a predetermined range, the adaptive filter outputs either the first or the second sound pick-up signal without performing the noise reduction process.

5. The noise reduction apparatus according to claim 1, wherein the voice direction detector detects the voice incoming direction based on magnitudes of the first and second sound pick-up signals.

6. The noise reduction apparatus according to claim 5, wherein the adaptive filter performs the noise reduction process to reduce a noise component carried by the first sound pick-up signal using the second sound pick-up signal when the first sound pick-up signal has a greater magnitude than the second sound pick-up signal whereas the adaptive filter performs the noise reduction process to reduce a noise component carried by the second sound pick-up signal using the first sound pick-up signal when the second sound pick-up signal has a greater magnitude than the first sound pick-up signal.

7. The noise reduction apparatus according to claim 5, wherein when a power difference that is a difference between magnitudes of the first and second sound pick-up signals is within a predetermined range, the adaptive filter outputs either the first or the second sound pick-up signal without performing the noise reduction process.

8. The noise reduction apparatus according to claim 1, wherein the voice direction detector detects the voice incoming direction based on a phase difference between the first and second sound pick-up signals and magnitudes of the first and second sound pick-up signals.

9. The noise reduction apparatus according to claim 1, wherein the speech segment determiner detects the speech segment based on the first sound pick-up signal when the first sound pick-up signal has a more advanced phase than the second sound pick-up signal whereas the speech segment determiner detects the speech segment based on the second sound pick-up signal when the second sound pick-up signal has a more advanced phase than the first sound pick-up signal.

10. The noise reduction apparatus according to claim 1, wherein signals are supplied to the voice direction detector as the first and second sound pick-up signals at a sampling frequency of 24 KHz or higher and signals are supplied to the adaptive filter as the first and second sound pick-up signals at a sampling frequency of 12 KHz or lower.

11. The noise reduction apparatus according to claim 1, wherein the speech segment determiner outputs more accurate speech segment information to the voice direction detector than speech segment information to the adaptive filter.

12. An audio input apparatus comprising:

a first face and an opposite second face that is apart from the first face with a specific distance;

a first microphone and a second microphone provided on the first face and the second face, respectively;

a speech segment determiner configured to determine whether or not a sound picked up by at least either the first microphone or the second microphone is a speech segment and to output speech segment information when it is determined that the sound picked up by the first or the second microphone is the speech segment;

a voice direction detector configured, when receiving the speech segment information, to detect a voice incoming direction indicating from which direction a voice sound travels, based on a first sound pick-up signal obtained based on a sound picked up by the first microphone and a second sound pick-up signal obtained based on a sound picked up by the second microphone and to output voice incoming-direction information when the voice incoming direction is detected; and

an adaptive filter configured to perform a noise reduction process using the first and second sound pick-up signals based on the speech segment information and the voice incoming-direction information.

13. A noise reduction method comprising the steps of:

determining whether or not a sound picked up by at least either a first microphone or a second microphone is a speech segment;

detecting a voice incoming direction indicating from which direction a voice sound travels, based on a first sound pick-up signal obtained based on a sound picked up by the first microphone and a second sound pick-up signal obtained based on a sound picked up by the second microphone, when it is determined that the sound picked up by the first or the second microphone is the speech segment; and

performing a noise reduction process using the first and second sound pick-up signals based on speech segment information indicating that the sound picked up by the first or the second microphone is the speech segment and voice incoming-direction information indicating the voice incoming direction.

14. The noise reduction method according to claim 13, the voice incoming direction is detected based on a phase difference between the first and second sound pick-up signals.

15. The noise reduction method according to claim 14, wherein the noise reduction process is performed to reduce a noise component carried by the first sound pick-up signal using the second sound pick-up signal when the first sound pick-up signal has a more advanced phase than the second sound pick-up signal whereas the noise reduction process is performed to reduce a noise component carried by the second sound pick-up signal using the first sound pick-up signal when the second sound pick-up signal has a more advanced phase than the first sound pick-up signal.

16. The noise reduction method according to claim 14, wherein when the phase difference is within a predetermined range, the adaptive filter outputs either the first or the second sound pick-up signal without performing the noise reduction process.

17. The noise reduction method according to claim 14, wherein the voice incoming direction is detected based on magnitudes of the first and second sound pick-up signals.

18. The noise reduction method according to claim 17, wherein the noise reduction process is performed to reduce a noise component carried by the first sound pick-up signal using the second sound pick-up signal when the first sound pick-up signal has a greater magnitude than the second sound pick-up signal whereas the noise reduction process is performed to reduce a noise component carried by the second sound pick-up signal using the first sound pick-up signal when the second sound pick-up signal has a greater magnitude than the first sound pick-up signal.

19. The noise reduction method according to claim 14, wherein the voice incoming direction is detected based on a phase difference between the first and second sound pick-up signals and magnitudes of the first and second sound pick-up signals.

20. The noise reduction method according to claim 19, wherein the speech segment is detected based on the first sound pick-up signal when the first sound pick-up signal has a more advanced phase than the second sound pick-up signal whereas the speech segment is detected based on the second sound pick-up signal when the second sound pick-up signal has a more advanced phase than the first sound pick-up signal.