SOUND MONITORING SYSTEM AND SPEECH COLLECTION SYSTEM

• US 20110082690A1
• Filed: 09/29/2010
• Published: 04/07/2011
• Est. Priority Date: 10/07/2009
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kawaguchi, Yohei, Togami, Masahito
• Granted Patent: US 8,682,675 B2
• Time in Patent Office: Days
• US Class Current: 704/201
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2201/403 Linear arrays of transducers
• CPC Class Codes: H04R 29/005 Microphone arrays
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

Monitoring accuracy degrades due to a noise in an environment where there are many sound sources other than those to be monitored. Easy initialization is required for an environment where many apparatuses operate. A sound monitoring system includes a microphone array having multiple microphones and a location-based abnormal sound monitoring section as a processing section. The location-based abnormal sound monitoring section is supplied with an input signal from the microphone array via a waveform acquisition section and a network. Using the input signal, the location-based abnormal sound monitoring section detects a temporal change in a sound source direction histogram. Based on a detected change result, the location-based abnormal sound monitoring section checks for abnormality in a sound field and outputs a monitoring result. The processing section searches for a microphone array near the sound source to be monitored. The processing section selects a sound field monitoring function for the sound source to be monitored based on various data concerning a microphone belonging to the searched microphone array.

Claims

1. A sound monitoring system comprising:

a microphone array having a plurality of microphones; and

a processing section,

wherein the processing section uses an input signal from the microphone array to detect a temporal change in a histogram of a sound source direction and, based on a detection result, determines whether abnormality occurs in a sound field.

2. The sound monitoring system according to claim 1, further comprising:

a display section,

wherein the display section displays an occurrence of abnormality when the processing section determines that abnormality occurs in a sound field.

3. A sound monitoring system comprising:

a microphone array having a plurality of microphones;

a processing section; and

a storage section,

wherein the storage section stores data concerning the microphone; and

wherein the processing section searches for the microphone array near a sound source to be monitored based on data concerning the microphone and selects a sound field monitoring function for the sound source to be monitored based on data concerning the microphone in the searched microphone array.

4. The sound monitoring system according to claim 3,

wherein the data concerning the microphone includes layout data on the microphone array;

and

wherein the processing section searches for the microphone array based on the layout data.

5. The sound monitoring system according to claim 3, further comprising:

an A/D converter connected to the microphone,

wherein the data concerning the microphone includes A/D synchronization data on the A/D converter connected to the microphone; and

wherein the processing section selects the sound field monitoring function based on the A/D synchronization data.

6. The sound monitoring system according to claim 5,

wherein the data concerning the microphone is stored in the storage section and includes directivity data on the microphone;

and

wherein the processing section selects the sound field monitoring function based on the directivity data when the A/D synchronization data for the searched microphone array indicates synchronization.

7. The sound monitoring system according to claim 6,

wherein the data concerning the microphone includes interval data for the microphone;

and

wherein the processing section selects the sound field monitoring function based on the interval data when the directivity data for the searched microphone array is identified to be omnidirectional.

8. The sound monitoring system according to claim 7,

wherein the processing section selects the sound field monitoring function having a direction estimation function based on a phase difference when the interval data for the searched microphone array is smaller than or equal to a specified value.

9. The sound monitoring system according to claim 7,

wherein the processing section selects the sound field monitoring function based on a sound volume ratio between the microphones when the interval data for the searched microphone array is not smaller than or equal to a specified value.

10. A speech collection system comprising:

a microphone array having a plurality of microphones; and

a processing section,

wherein the processing section generates a histogram for each sound source from an input signal for the microphone array and detects orientation of the sound source based on a variation in the generated histogram.

11. The speech collection system according to claim 10,

wherein the processing section calculates a cross-microphone-array feature amount based on the histogram generated for each sound source and detects the sound source orientation based on the calculated cross-microphone-array feature amount.

12. The speech collection system according to claim 11,

wherein the processing section calculates the calculated cross-microphone-array feature amount by calculating a direction histogram entropy from the histogram for each sound source.

13. The speech collection system according to claim 10, further comprising:

a plurality of display sections,

wherein the processing section specifies the display section found along the detected sound source orientation and provides control to display an image on the specified display section.

14. The speech collection system according to claim 10,

wherein the processing section specifies the microphone array corresponding to orientation of the sound source based on the detected sound source orientation and provides control to record an input signal for the specified microphone array.