JP2007300295A - Conference microphone device and conference microphone control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conference microphone device capable of increasing the number of simultaneous speakers while preventing howling. <P>SOLUTION: A howling pattern storage unit 35 stores a howling generation microphone ON pattern indicating a microphone unit 12 in an ON state when howling generation is detected. A microphone output request data acquiring unit 36 acquires microphone output request data from the microphone unit 12. A pattern comparing unit 38 compares a request answer microphone ON pattern representing a microphone unit 12 which is in an ON state when the microphone output request data are acquired and the microphone unit 12 sending the microphone output request data with the howling generation microphone ON pattern. A microphone ON control unit 39 suppresses ON control over the microphone unit 12 sending the microphone output request data when both the pattern match each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a conference microphone device including a plurality of microphone units, and more particularly to a technique for preventing howling.

  Conventionally, a conference microphone device includes a plurality of microphone units for a plurality of speakers, and each speaker's voice is input to a nearby microphone unit and output from a speaker or the like. In the conference microphone device, howling occurs when the loudness gain between the sound input by the microphone and the sound output by the speaker or the like is high. In order to prevent howling, the amplitude and phase of the audio output signal are controlled (see, for example, Patent Document 1).

  Further, in the conference microphone device, howling occurs not only when the gain of a single microphone is high but also when a plurality of microphones are simultaneously turned on. In the conference microphone device, such howling due to simultaneous microphone ON occurs most frequently.

In order to prevent the above-described howling due to the simultaneous microphones ON, conventionally, it has been usual to preset the maximum number of microphones that are simultaneously ON. The maximum number of microphones ON is called the maximum number of simultaneous speakers. The conventional conference microphone device is configured to control ON / OFF of each microphone, and the microphone is turned on within a range not exceeding the maximum number of simultaneous speakers. When there is a microphone ON request that exceeds the maximum number of simultaneous speakers, the conference microphone device suppresses the ON control of the microphone that has sent the microphone ON request, that is, the corresponding microphone is left OFF. Was preventing howling.
JP-A-2-309856

  However, since the conventional conference microphone device turns on the microphone within a range that does not exceed the preset maximum number of simultaneous speakers, there are cases where the microphone cannot be turned on even in a combination of microphones that do not generate howling. There is a problem that an unnecessary limit on the number of simultaneous speakers is added.

  More specifically, the maximum number of simultaneous speakers is conventionally set to be less than the minimum number of microphones ON that can cause howling. However, even if the number of simultaneously ON microphones is the same, there are cases where howling occurs and howling does not occur depending on the combination of microphones ON. Therefore, even if the number of microphones ON exceeds the maximum number of simultaneous speakers, there is a combination of microphones ON that does not generate howling. However, such a combination is not allowed in the past, and the number of simultaneous speakers is unnecessarily limited.

  The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a conference microphone device that can increase the number of simultaneous speakers while preventing howling.

  The conference microphone device of the present invention includes a plurality of microphone units, microphone ON data acquisition means for detecting the ON / OFF state of each microphone unit by acquiring ON / OFF data of each of the plurality of microphone units, and ON A sound adding means for adding sound input from a microphone unit in a state, a howling detecting means for detecting howling from the output signal of the sound adding means, and an ON state when howling is detected by the howling detecting means A howling pattern storage means for storing a howling generation microphone ON pattern representing a microphone unit in the microphone, a microphone output request data acquisition means for acquiring microphone output request data from each of the plurality of microphone units, and the microphone output request data acquired Is in the ON state when Pattern comparison means for comparing a request response microphone ON pattern that represents both the microphone unit and the microphone unit that has sent the microphone output request data to the howling generation microphone ON pattern, and the request response microphone ON pattern is the howling occurrence. And a microphone ON control means for suppressing ON control of the microphone unit that has sent the microphone output request data when the microphone ON pattern matches.

  With this configuration, a howling generation microphone ON pattern representing a microphone unit that is in an ON state when howling is detected is stored, and a request response microphone ON pattern when a microphone output request is satisfied is referred to as a howling generation microphone ON pattern. Comparison is performed, and microphone ON control is performed based on the comparison result. If the two patterns match, the microphone ON control is suppressed, and if they do not match, the microphone ON control is executed. As a result, the number of microphones ON can be increased within a range that does not match the howling generation microphone ON pattern. Therefore, the number of simultaneous speakers can be increased while preventing howling.

  According to another aspect of the present invention, there is provided a microphone control method for controlling ON / OFF of a plurality of microphone units, wherein each microphone unit is turned ON by acquiring ON / OFF data of each of the plurality of microphone units. / OFF state is detected, the voice input from the microphone unit in the ON state is added, howling occurrence is detected from the added audio signal, and howling representing the microphone unit that is in the ON state when the howling occurrence is detected The generated microphone ON pattern is stored, the microphone output request data is acquired from each of the plurality of microphone units, and the microphone unit in the ON state and the microphone output request data are sent when the microphone output request data is acquired. Request response microphone ON pattern that represents both the microphone unit and the howling Compared to raw microphone ON pattern, if the request response microphone ON pattern coincides with the howling occurrence microphone ON pattern, suppressing ON control of the microphone unit which sent the microphone output request data. This aspect also provides the above-described advantages of the present invention.

  The present invention can increase the number of simultaneous speakers while preventing howling by providing a configuration for performing microphone ON control by comparing the howling generation microphone ON pattern and the request response microphone ON pattern as described above. It is possible to provide a conference microphone device having the effect described above.

  Hereinafter, a conference microphone device according to an embodiment of the present invention will be described with reference to the drawings.

  A conference microphone device according to an embodiment of the present invention is shown in FIG. In FIG. 1, the conference microphone device 11 includes a plurality of microphone units 12, a loudspeaker 13, and a controller 14 connected to each microphone unit 12 and the loudspeaker 13.

  Each microphone unit 12 includes a microphone 21 that inputs sound, a microphone switch 22 that turns ON / OFF the sound input from the microphone 21, and a microphone output request unit 23 that requests ON / OFF control of the microphone switch 22. ing.

  ON / OFF of the microphone switch 22 is controlled by the control unit 14. The microphone switch 22 performs a switching operation according to a control signal from the control unit 14. The audio signal is sent from the microphone unit 12 to the control unit 14 when the microphone switch 22 is ON. A state in which the microphone switch 22 is ON is referred to as an ON state.

  The microphone output request unit 23 sends microphone output request data to the control unit 14. The microphone output request data is data requesting that the microphone unit 12 be turned on. The microphone output request unit 23 detects the start of speaking by the speaker based on the voice input to the microphone 21. When the microphone output request unit 23 detects the start of utterance, the microphone output request unit 23 sends microphone output request data to the control unit 14.

  The microphone output request unit 23 also sends output OFF request data to the control unit 14. The microphone output request unit 23 detects the end of generation based on the voice input to the microphone 21, and sends output OFF request data to the control unit 14 when the end of generation is detected.

  In the above example, the microphone output request unit 23 automatically generates microphone output request data. In another example, the microphone output request data is generated in response to a manual operation. In this case, a manual operation member such as a button is provided. When the manual operation member is operated, this operation is accepted by the microphone output request unit 23, and the microphone output request unit 23 generates microphone output request data. Output OFF request data may also be generated in response to a manual operation.

  Further, the microphone output request unit 23 may be configured to perform both the automatic request operation and the request operation according to the manual operation.

  The loudspeaker 13 is composed of one or more speakers, and outputs an audio signal supplied from the controller 14.

  Next, the configuration of the control unit 14 will be described. The control unit 14 is configured by a computer that realizes functions of various configurations described below. The control unit 14 is a device that controls the entire conference microphone device 11, adds the audio signals input from the plurality of microphone units 12, and outputs the result to the loudspeaker unit 13. Further, the control unit 14 individually controls ON / OFF of each microphone unit 12 according to the microphone output request data from each microphone unit 12.

  In the control unit 14, the audio adding unit 31 adds (mixes) audio signals input from one or more microphone units 12 in the ON state. The audio signal after the addition is supplied from the control unit 14 to the loudspeaker unit 13 and input to the howling detection unit 32 in the control unit 14. The howling detection unit 32 detects howling in the audio signal after the addition. The howling detection unit 32 is configured by FFT or the like, and performs processing that regards howling as occurring when a peak value of a single frequency reaches a certain threshold level. The howling detection unit 32 outputs a howling detection signal when howling occurs.

  The microphone ON data acquisition unit 33 detects the ON / OFF state of each microphone unit 12 by acquiring the ON / OFF data of each microphone unit 12. The ON / OFF data is output from the microphone switch 22 and input to the microphone ON data acquisition unit 33 of the control unit 14. The microphone ON data acquisition unit 33 can recognize the ON / OFF state of each of the plurality of microphone units 12 in real time.

  The howling pattern detection unit 34 detects the howling occurrence microphone ON pattern and stores it in the howling pattern storage unit 35. The howling generation microphone ON pattern is data representing the microphone unit 12 in the ON state when howling detection is detected by the howling detection unit 32. The howling pattern detection unit 34 may store a plurality of howling occurrence microphone ON patterns.

  The generation process of the howling generation microphone ON pattern is as follows. A howling detection signal is input from the howling detection unit 32 to the howling pattern detection unit 34. The howling pattern detection unit 34 acquires the ON / OFF state data of each microphone unit 12 from the microphone ON data acquisition unit 33 when a howling detection signal is input. And howling pattern detection part 34 generates data which specifies which microphone unit 12 was in an ON state at the time of howling. This data is stored in the howling pattern storage unit 35 as a howling generation microphone ON pattern.

  The microphone output request data acquisition unit 36 acquires microphone output request data and output OFF request data from the microphone output request unit 23 of each microphone unit 12. As described above, the microphone output request data is input from the microphone output request unit 23 to the control unit 14 at the start of generation. The output OFF request data is input from the microphone output request unit 23 to the control unit 14 at the end of generation. The microphone output request data acquisition unit 36 supplies microphone output request data to the request response pattern generation unit 37 and supplies output OFF request data to the microphone ON control unit 39.

  The request response pattern generation unit 37 generates a request response microphone ON pattern. The request response microphone ON pattern is data representing both the microphone unit 12 that is in the ON state when the microphone output request data is acquired and the microphone unit 12 that has sent the microphone output request data. In short, the request response microphone ON pattern is a microphone pattern in an ON state when it is assumed that the corresponding microphone is turned ON according to the microphone output request data.

  The request response microphone ON pattern generation process is as follows. When the request response pattern generation unit 37 acquires the microphone output request data from the microphone output request data acquisition unit 36, the request response pattern generation unit 37 receives the current microphone ON data from the microphone ON data acquisition unit 33. The current microphone ON data is data of the microphone unit 12 that is already in the ON state when the microphone output request data is input. The request response pattern generation unit 37 adds the microphone unit 12 that has sent the microphone output request data to the current microphone ON data. The data after the addition is data of a combination of the microphone units 12 that are turned on when responding to the microphone output request. This data is generated as a request response microphone ON pattern.

  The pattern comparison unit 38 compares the request response microphone ON pattern generated by the request response pattern generation unit 37 as described above with the howling generation microphone ON pattern stored in the howling pattern storage unit 35. The microphone ON data acquisition unit 33 stores a plurality of howling generation microphone ON patterns. The pattern comparison unit 38 compares each howling occurrence microphone ON pattern with the request response microphone ON pattern to determine whether or not the patterns match.

  The microphone ON control unit 39 sends an ON / OFF control signal to each microphone unit 12 to individually control ON / OFF of each microphone unit 12. More specifically, the microphone ON control unit 39 is configured to control each of the twelve microphone switches 22, and a control signal is sent to the microphone switch 22.

  The microphone ON control unit 39 performs ON control of the microphone unit 12 that has sent the microphone output request data in accordance with the comparison result of the pattern comparison unit 38. When the request response microphone ON pattern matches the howling occurrence microphone ON pattern as a result of the comparison by the pattern comparison unit 38, the microphone ON control unit 39 suppresses the ON control of the microphone unit 12 that has sent the microphone output request data. That is, the microphone ON control unit 39 maintains the corresponding microphone unit 12 in the OFF state. By such control, combinations of microphones that cause howling can be avoided, and howling can be prevented.

  On the other hand, if there is no howling occurrence microphone ON pattern that matches the request response microphone ON pattern as a result of the comparison by the pattern comparison unit 38, the microphone ON control unit 39 turns on the microphone unit 12 that has sent the microphone output request data. To do. By such control, more microphone units 12 can be turned on within a range where no howling occurs, and the number of simultaneous speakers can be increased.

  In addition, the microphone ON control unit 39 is configured to perform control to turn off the corresponding microphone unit 12 when the output OFF request data is acquired from the microphone output request data acquisition unit 36.

  The configuration and function of each part of the conference microphone device 11 have been described above. Next, the operation of the conference microphone device 11 will be described using a specific example.

  Here, first, an operation for generating and storing a howling generation microphone ON pattern will be described. When sound is input from the microphone unit 12 in the ON state to the control unit 14, the sound signals from the plurality of microphone units 12 are added by the sound adding unit 31. The output signal of the sound adder 31 is supplied to the loudspeaker 13 and also input to the howling detector 32. When detecting howling, the howling detection unit 32 outputs a howling detection signal to the howling pattern detection unit 34.

  When a howling detection signal is input, the howling pattern detection unit 34 acquires data on the ON / OFF state of each microphone unit 12 from the microphone ON data acquisition unit 33. The ON / OFF data of each microphone unit 12 is sent from the microphone switch 22 of the microphone unit 12 to the control unit 14 and input to the microphone ON data acquisition unit 33. The howling pattern detection unit 34 generates a howling generation microphone ON pattern based on the acquired information.

  FIG. 2 is an example of a howling generation microphone ON pattern. In FIG. 2, reference numeral 41 is attached to the howling generation microphone ON pattern. In this example, the number of microphone units 12 is four. Then, howling occurs when the microphones 1, 2, and 4 are simultaneously ON and the microphone 3 is OFF. In this case, the howling generation microphone ON pattern 41 is (microphone 1, microphone 2, microphone 3, microphone 4) = (ON, ON, OFF, ON). Thus, the howling generation microphone ON pattern 41 is data for specifying which microphone unit 12 is in the ON state when the howling occurs. The howling generation microphone ON pattern 41 is stored in the howling pattern storage unit 35.

  The howling pattern detection unit 34 generates a howling generation microphone ON pattern 41 and stores it in the howling pattern storage unit 35 every time howling is detected. Therefore, the howling pattern storage unit 35 stores a plurality of howling generation microphone ON patterns 41.

  The howling generation microphone ON pattern 41 may be generated during pre-adjustment work at the conference site before the conference microphone device 11 is used for the conference. In this case, various combinations of microphone units 12 are tried. Audio is input from each combination of microphone units 12. If howling occurs in a certain combination, a howling generation microphone ON pattern corresponding to the combination is generated and stored. If howling does not occur in another combination, a howling generation microphone ON pattern corresponding to that combination is not generated.

  Within the scope of the present invention, the howling generation microphone ON pattern may not be generated by the pre-adjustment operation. The howling generation microphone ON pattern may be generated when howling occurs even during a conference.

  In this regard, for example, howling may occur during the use of the conference despite the pre-adjustment work. Also in this case, a howling generation microphone ON pattern may be generated and stored.

  The operation for generating and storing the howling generation microphone ON pattern has been described above. Next, an operation for preventing howling using the howling generation microphone ON pattern will be described.

  Here, howling prevention operation will be described using the specific example of FIG. Similar to the example of FIG. 2, the number of microphone units 12 is four in the example of FIG. 3.

  When the microphone output request data 42 is sent from one microphone unit 12 to the control unit 14 after the operation of the conference microphone device 11 is started, the microphone output request data 42 is input to the microphone output request data acquisition unit 36. This is supplied to the request response pattern generation unit 37. In the example of FIG. 3, the microphone output request data 42 is shown in the form of the ON / OFF pattern of each microphone, as in FIG. Since the microphone output request data 42 is acquired from the microphone 2, the microphone output request data 42 is (microphone 1, microphone 2, microphone 3, microphone 4) = (OFF, ON, OFF, OFF).

  Upon receiving the microphone output request data 42, the request response pattern generation unit 37 receives the current microphone ON data 43 from the microphone ON data acquisition unit 33. The current microphone ON data 43 is data representing the microphone unit 12 that is in the ON state when the microphone output request data 42 is input. In the example of FIG. 3, the microphone ON data 43 is also represented by the ON / OFF pattern of each microphone. Since the microphones 1 and 4 are ON and the microphones 2 and 3 are OFF, the microphone ON data 43 is (MIC1, MIC2, MIC3, MIC4) = (ON, OFF, OFF, ON). .

  The request response pattern generation unit 37 generates a request response microphone ON pattern 44 based on the microphone output request data 42 and the current microphone ON data 43. Here, both data are added, and as a result, the request response microphone ON pattern 44 becomes (MIC 1, MIC 2, MIC 3, MIC 4) = (ON, ON, OFF, ON). The request response microphone ON pattern 44 is a pattern in which the microphone 2 that has sent the output request is turned ON in addition to the microphones 1 and 4 that are already in the ON state. Therefore, it is assumed that the request response microphone ON pattern 44 responds to the output request. The microphone pattern is on.

  When the request response microphone ON pattern 44 is generated, the pattern comparison unit 38 compares the request response microphone ON pattern 44 with the howling generation microphone ON pattern 41 stored in the howling pattern storage unit 35 and the patterns match. It is determined whether or not.

  In the example of FIG. 3, both patterns match. In this case, if the microphone 2 is turned on in response to the microphone output request data, occurrence of howling is predicted. Therefore, in order not to generate howling, the microphone ON control unit 39 suppresses the ON control of the microphone 2 that has transmitted the microphone output request data. The microphone 2 is kept off. In this way, the maximum number of simultaneous speakers of the microphone can be controlled so as not to generate howling.

  Unlike the example of FIG. 3, it is assumed that the request response microphone ON pattern 44 does not match the howling generation microphone ON pattern 41. In this case, the microphone ON control unit 39 turns on the microphone unit 12 according to the microphone output request data. At this time, a switch ON control signal is sent to the microphone switch 22 of the corresponding microphone number. Thus, since the determination process based on the howling occurrence microphone ON pattern 41 is performed, the number of microphones that can be simultaneously turned on can be maximized within a range where no howling occurs.

  In the example of FIG. 3, one howling generation microphone ON pattern 41 is shown. However, as described above, a plurality of howling generation microphone ON patterns 41 may be processed. The pattern comparison unit 38 compares each howling occurrence microphone ON pattern 41 with the request response microphone ON pattern 44 to determine pattern matching. If one howling generation microphone ON pattern 41 matches, the ON control of the microphone unit 12 is suppressed.

 In the above example, the microphone output request data acquisition unit 36 acquires microphone output request data from one microphone unit 12. However, the microphone output request data acquisition unit 36 may acquire microphone output request data from the plurality of microphone units 12.

  Further, in the above example, the comparison process of the pattern comparison unit 38 is performed when there is a change in the acquisition data by the microphone output request data acquisition unit 36. However, the comparison process and the microphone ON control may be performed at regular time intervals.

  Further, the present embodiment is a technique for detecting howling once generated and preventing subsequent howling. Therefore, it is necessary to generate howling once. Regarding this point, as described above, it is preferable to generate and store a howling generation microphone ON pattern at the time of pre-adjustment in the field, thereby avoiding howling during actual operation.

  The conference microphone device 11 according to the embodiment of the present invention has been described above. According to the present embodiment, the conference microphone device 11 stores a howling generation microphone ON pattern 41 representing a microphone unit that is in an ON state when howling is detected, and a request when responding to a microphone output request. The response microphone ON pattern 44 is compared with the howling generation microphone ON pattern 41, and the microphone ON control is performed based on the comparison result. The conference microphone device 11 suppresses the microphone ON control if the two patterns match, and performs the microphone ON control if the two patterns are different. As a result, the number of microphones ON can be increased within a range that does not match the howling generation microphone ON pattern. Therefore, the number of simultaneous speakers can be increased while preventing howling.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and it goes without saying that those skilled in the art can modify the above-described embodiments within the scope of the present invention.

  As described above, the conference microphone device according to the present invention has an effect that the number of simultaneous speakers can be increased while preventing howling, and is useful as a conference microphone device and the like.

The block diagram of the conference microphone apparatus in embodiment of this invention Figure showing howling generation microphone ON pattern Diagram showing howling prevention processing using howling generation microphone ON pattern

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Conference microphone apparatus 12 Microphone unit 13 Loudspeaker part 14 Control part 21 Microphone 22 Microphone switch 23 Microphone output request part 31 Voice addition part 32 Howling detection part 33 Microphone ON data acquisition part 34 Howling pattern detection part 35 Howling pattern memory | storage part 36 Microphone output Request data acquisition unit 37 Request response pattern generation unit 38 Pattern comparison unit 39 Microphone ON control unit 41 Howling generation microphone ON pattern 42 Microphone output request data 43 Microphone ON data 44 Request response microphone ON pattern

Claims (2)

Multiple microphone units,
Microphone ON data acquisition means for detecting the ON / OFF state of each microphone unit by acquiring the ON / OFF data of each of the plurality of microphone units;
Audio adding means for adding audio input from the microphone unit in the ON state;
Howling detecting means for detecting howling occurrence from an output signal of the voice adding means;
Howling pattern storage means for storing a howling generation microphone ON pattern representing a microphone unit that is in an ON state when howling detection is detected by the howling detection means;
Microphone output request data acquisition means for acquiring microphone output request data from each of the plurality of microphone units;
A pattern comparison that compares a request response microphone ON pattern that represents a microphone unit that is in an ON state when the microphone output request data is acquired and a microphone unit that has sent the microphone output request data with the howling generation microphone ON pattern. Means,
Microphone ON control means for suppressing ON control of the microphone unit that has sent the microphone output request data when the request response microphone ON pattern matches the howling generation microphone ON pattern;
A conference microphone device comprising: A microphone control method for controlling ON / OFF of a plurality of microphone units,
Detecting the ON / OFF state of each microphone unit by acquiring the ON / OFF data of each of the plurality of microphone units,
Add the audio input from the microphone unit in the ON state,
Detect howling from the audio signal after addition,
Storing a howling generation microphone ON pattern representing a microphone unit in an ON state when a howling generation is detected;
Obtaining microphone output request data from each of the plurality of microphone units;
A request response microphone ON pattern representing both a microphone unit that is in an ON state when the microphone output request data is acquired and a microphone unit that has sent the microphone output request data is compared with the howling generation microphone ON pattern. ,
A conference microphone control method, wherein when the request response microphone ON pattern matches the howling generation microphone ON pattern, ON control of the microphone unit that has sent the microphone output request data is suppressed.

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