JPH08123437A - Noise control unit - Google Patents

Abstract

PURPOSE: To provide a wide noise controlled area with small hardware as to the noise control unit which uses a control speaker and plural error detectors. CONSTITUTION: The control sound of the control speaker 2 is made to operate on the noise generated by a noise source 1 and error sounds are detected by the error detectors 3a-3n, whose detection signals are added. The output signal of an echo canceling filter 7 is subtracted from the addition signal and the result is inputted to an adaptive filter 8, a filtered X filter 6, and the error input of a coefficient update unit 9. The output of the filter 6 is inputted to the reference input of the coefficient update unit 9, which performs coefficient update operation according to LMS algorithm, etc., to update the coefficient of the adaptive filter 8 so that the error input signal is always small. The output signal of the adaptive filter 8 is inputted to the control speaker 2 and also inputted to the filter 7. The same characteristics with the filter 6 are set in the filter 7, so a sound feedback loop is canceled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise control device using active noise control in a noisy environment.

[0002]

2. Description of the Related Art In recent years, an active noise control method has been proposed in which a control sound is output from a speaker by using a digital signal processing technique to mute environmental noise at a listening position.

Conventionally, a noise control device of this type generally has a structure shown in FIG. The configuration will be described below with reference to FIG. 7. In the figure, the detection signal from the noise detector 10 of the noise source 1 is processed by the adaptive filters 8a and 8b to generate control sound from the control speakers 2a and 2b, and the noise from the noise source 1 is reduced by this control sound. . The error sound between the noise from the noise source 1 and the control sound from the control speakers 2a and 2b is detected by the error detectors 3a and 3b and input to the coefficient updaters 9a and 9b. On the other hand, the noise detection signal is a known filtered X filter 6a, 6b, 6
Filtered by c and 6d, and coefficient updating unit 9
a and 9b.

[0004]

However, in the conventional noise control device as described above, when a plurality of control speakers and error detectors are used to increase the noise control area, a so-called multi-filtered X algorithm is used. Used. Multi-filtered X algorithms are already known, for example SJ Elliott, Electro
n. Lett. vol.21, pp979-981, 1985.
In the case of FIG. 7, two control speakers and two error detectors are used, so that the transfer functions from the control speaker to the error detector are H _r1 , H _r2 , H _l1 ,
Since there are four types of H _l2 , four filtered X filters and two adaptive filters are required. Further, if there is acoustic feedback, an echo cancellation filter or the like is required, resulting in a huge amount of hardware. was there.

The present invention solves the above problems and provides a noise control device capable of reducing the scale of hardware such as a filter even when a plurality of error detectors and control speakers are required. The purpose is.

[0006]

In order to achieve the above object, a first invention is a control speaker installed near a noise source, and a plurality of error detectors installed equidistant from the control speaker. An adder that adds the output of each error detector,
A subtracter for subtracting the output of the adder and the output of the second filter; an adaptive filter and a first filter for inputting the output of the subtractor; an output of the first filter and the subtractor; A coefficient updater for inputting an output, and the second filter for inputting an output of the adaptive filter,
The coefficient of the adaptive filter is updated according to the output of the coefficient updater, the output of the adaptive filter is input to the control speaker, and the error of each characteristic of the first filter and the second filter is detected from the control speaker. It is equal to the sum of transfer functions to the vessel.

A second aspect of the invention is to provide a plurality of control speakers installed in the vicinity of the noise source and one control speaker in the vicinity of each control speaker.
Error detectors installed equidistant from each other, an adder for adding the outputs of the error detectors, a subtracter for subtracting the output of the adder and the output of the second filter, and An adaptive filter for inputting an output and a first filter; a coefficient updater for inputting an output of the first filter and an output of the subtractor; and a second filter for inputting an output of the adaptive filter. Then, the coefficient of the adaptive filter is updated according to the output of the coefficient updater, the output of the adaptive filter is input to each control speaker, and the characteristics of the first filter and the second filter are output from the control speaker. It is equal to the sum of the transfer functions up to the error detector installed in the vicinity.

A third aspect of the present invention adds a plurality of control speakers installed near a noise source, error detectors installed at a plurality of equal distances near each control speaker, and outputs of the error detectors. An adder, a subtractor for subtracting the output of the adder and the output of the second filter, an adaptive filter and a first filter for inputting the output of the subtractor, and an output of the first filter And a coefficient updater for inputting the output of the subtracter, and the second filter for inputting the output of the adaptive filter, and updating the coefficient of the adaptive filter according to the output of the coefficient updater. The output of the adaptive filter is input to each control speaker, the distance between the control speaker and each error detector in the vicinity is made equal to each other for each control speaker, and the characteristics of the first filter and the second filter are controlled by the control speaker. From Formed by equal to the sum of the transfer function to each error detector near the.

According to a fourth aspect of the present invention, a noise detector for detecting information of a noise source, a control speaker installed in the vicinity of the noise source, a plurality of error detectors installed equidistant from the control speaker, An adder for adding the outputs of the error detector, a subtractor for subtracting the output of the noise detector and the output of the second filter, and an adaptive filter and a first filter for inputting the output of the subtractor , A coefficient updater for inputting the output of the first filter and an output of the adder, and the second filter for inputting the output of the adaptive filter, wherein the adaptation is performed according to the output of the coefficient updater. The coefficient of the filter is updated, the output of the adaptive filter is input to the control speaker, the characteristic of the first filter is made equal to the sum of the transfer functions from the control speaker to each error detector, and the characteristic of the second filter is adjusted. Control characteristics Formed by equal to a transfer function from the speaker to the noise detector.

According to a fifth aspect of the present invention, a noise detector for detecting information on a noise source, a plurality of control speakers installed equidistant from the noise detector, and one equidistant device in the vicinity of each control speaker. The error detector installed in the above, an adder for adding the outputs of the error detectors, a subtractor for subtracting the output of the noise detector from the output of the second filter, and the output of the subtractor The adaptive filter and the first filter, the coefficient updater that inputs the output of the first filter and the output of the adder, and the second filter that inputs the output of the adaptive filter, and the coefficient The coefficient of the adaptive filter is updated according to the output of the updater, the output of the adaptive filter is input to the control speaker, and the characteristic of the first filter is controlled from the control speaker to the error detector installed in the vicinity thereof. Sum of transfer functions Equal, formed by equal characteristics of the second filter to the sum of the transfer function from the control speaker to the noise detector.

According to a sixth aspect of the present invention, a noise detector for detecting information of a noise source, a plurality of control speakers installed equidistant from the noise detector, and a plurality of equidistant devices in the vicinity of each control speaker. The installed error detector, an adder for adding the outputs of the error detectors, a subtractor for subtracting the output of the noise detector and the output of the second filter, and the output of the subtractor are input. An adaptive filter and a first filter, a coefficient updater for inputting the output of the first filter and an output of the adder, and the second for inputting the output of the adaptive filter
Of the adaptive filter, the coefficient of the adaptive filter is updated according to the output of the coefficient updater, the output of the adaptive filter is input to the control speaker, and the distance between the control speaker and each error detector in the vicinity thereof is calculated. The characteristics of the first filter are made equal to each other, the characteristics of the first filter are made equal to the sum of the transfer functions from the control speaker to the respective error detectors in the vicinity thereof, and the characteristics of the second filter are made noise from the respective control speakers. It is equal to the sum of the transfer functions to the detector.

[0012]

According to the present invention, as described above, the control speaker and the respective error detectors are installed at equal distances, and the transfer functions from the control speaker to the respective error detectors are made equal to each other. Is set in the first and second filters, and the transfer function from the control speaker to the noise detector is made equal in the configuration in which the noise detector and each control speaker are equidistantly installed. The sum of the transfer functions
By setting the filter of (1), a wide control area can be realized with a small amount of hardware corresponding to one dimension.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG.
Will be described with reference to. This embodiment equalizes the transfer function from the control speaker to each error detector by installing a plurality of error detectors equidistant from the control speaker, which allows wide control with less hardware corresponding to one dimension. It has the characteristic of realizing an area.

In FIG. 1, 1 is a noise source and 2 is a noise source 1.
Control speakers 3a, 3b, 3c, installed near the
.., 3n are error detectors installed equidistant from the control speaker 2, 4 is an adder for adding the output of each error detector, 5
Is a subtracter, and 6 is a filtered X having a characteristic equal to the sum of transfer functions from the control speaker 2 to each error detector.
A filter (hereinafter abbreviated as FX), and 7 is an echo canceller (hereinafter, EC) set to the same characteristics as the FX filter 6.
A filter, 8 is an adaptive filter, and 9 is a coefficient updater.

The operation of this embodiment will be described below. The control sound of the control speaker 2 is applied to the noise emitted from the noise source 1, and this error sound is detected by the error detectors 3a to 3n,
The adder 4 adds the respective detection signals. The subtractor 5 subtracts the output signal of the EC filter 7 from the added signal, and the subtracted error signal is used as the adaptive filter 8 and the FX filter 6.
Is input to the error input of the coefficient updater 9. The output signal of the FX filter 6 is input to the reference input of the coefficient updater 9, and the coefficient updater 9 performs a coefficient update operation using an LMS (Least Mean Square) algorithm or the like. Update so that the input signal is always small. Then, the output signal of the adaptive filter 8 for which a new coefficient is set is input to the control speaker 2 and the EC filter 7. Where EC
Since the filter 7 has the above-described characteristics, the acoustic feedback loop from the control speaker 2 to the error detectors 3a to 3n can be canceled.

As described above, according to the configuration of this embodiment,
The control sound emitted from the control speaker is detected by each error detector, and since each error detector is installed at a position that is equidistant from the control speaker, transmission from the control speaker to each error detector is performed. The functions are all the same,
The FX filter 6 has a characteristic equal to the sum of these transfer functions.
By setting the EC filter 7, even if an arbitrary number of error detectors are installed, a wide control area can be realized with a small amount of hardware equivalent to one dimension.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, one error detector is installed near each of the plurality of control speakers to equalize the distance between each control speaker and the error detector. The characteristic is that the transfer functions up to are equalized and a wide control area can be realized with a small amount of hardware corresponding to one dimension.

In FIG. 2, 1 is a noise source, 2a, 2b,
, 2n are control speakers installed near the noise source 1, 3a, 3b, 3c, ..., 3n are error detectors installed equidistant from the respective control speakers, and 4 are error detectors. An adder for adding outputs 3a to 3n, 5 is a subtractor, 6
Is an FX filter set to a characteristic equal to the sum of transfer functions from the control speaker to the error detector, and 7 is an FX filter 6
An EC filter having the same characteristics as the above, 8 is an adaptive filter, and 9 is a coefficient updater.

The operation of this embodiment will be described below. The control speaker 2a, 2b, 2 is added to the noise emitted from the noise source 1.
.., 2n control sounds are applied, the error sounds are detected by the error detectors 3a to 3n, and the adder 4 adds the respective detection signals. The subtractor 5 subtracts the output signal of the EC filter 7 from the addition signal, and the subtracted error signal is input to the adaptive filter 8, the FX filter 6, and the error input of the coefficient updater 9. The output signal of the FX filter 6 is input to the reference input of the coefficient updater 9, and the coefficient updater 9 uses the LMS (Lea
The coefficient update calculation is performed by the st Mean Square) algorithm or the like, and the coefficient of the adaptive filter 8 is updated by the calculation result so that the error input signal is always small. Then, the output signal of the adaptive filter 8 for which a new coefficient is set is input to the control speaker 2 and the EC filter 7
Is also entered. Since the EC filter 7 has the above-mentioned characteristics, the acoustic feedback loop from each control speaker to the error detector can be canceled.

As described above, according to the configuration of this embodiment,
The control sound emitted from the control speaker is detected by the error detectors installed at equal distances near each control speaker,
At this time, the transfer functions from the control speaker to each error detector are all the same, and by setting the characteristics equal to the sum of these transfer functions to the FX filter 6 and the EC filter 7, the control speaker and the error detector are connected. Even when a plurality of arbitrary units are installed, a wide control area can be realized with a small amount of hardware corresponding to one dimension.

Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, a plurality of error detectors are installed in the vicinity of each control speaker, and the distances between the control speaker and the error detectors in the vicinity thereof are made equal so that the error from the control speaker to each error detector is transmitted. It has a feature that the functions can be made equal and a wide control area can be realized with a small amount of hardware corresponding to one dimension.

In FIG. 3, 1 is a noise source, 2a, 2b,
, 2n are control speakers installed in the vicinity of the noise source 1, 3aa, 3ab, ..., 3an are error detectors installed equidistant from the control speaker 2a, similarly 3n.
a, 3nb, ..., 3nm are error detectors 4a, 4b, ..., 4 installed equidistant from the control speaker 2n.
n and 4 are adders, 5 is a subtractor, 6 is an FX filter set to a characteristic equal to the sum of transfer functions from the control speaker to each error detector, 7 is an EC filter set to the same characteristic as the FX filter 6, Reference numeral 8 is an adaptive filter, and 9 is a coefficient updater.

The operation of this embodiment will be described below. The control speaker 2a, 2b, 2 is added to the noise emitted from the noise source 1.
The control sounds of c, ..., 2n are applied, and the error sound is detected by the error detectors 3aa to 3 nm, and the adders 4a, 4b,
.., 4n, 4 add the respective error detection signals. The subtractor 5 subtracts the output signal of the EC filter 7 from the addition signal, and the subtracted error signal is output from the adaptive filter 8 and the F filter.
The error is input to the X filter 6 and the coefficient updater 9.
The output signal of the FX filter 6 is input to the reference input of the coefficient updater 9, and the coefficient updater 9 is LMS (Least Mean Square).
A coefficient update operation is performed by an algorithm or the like, and the coefficient of the adaptive filter 8 is updated based on the operation result so that the error input signal is always small. Then, the output signal of the adaptive filter 8 for which a new coefficient is set is input to the control speaker 2 and the EC filter 7.
Since the EC filter 7 has the above-mentioned characteristics, the acoustic feedback loop from each control speaker to the error detector can be canceled.

As described above, according to the configuration of this embodiment,
The control sound emitted from the control speaker is detected by a plurality of error detectors installed equidistantly in the vicinity of each control speaker, and at this time, the transfer functions from the control speaker to each error detector are all the same, By setting the characteristics equal to the sum of these transfer functions to the FX filter 6 and the EC filter 7, even if an arbitrary plurality of error detectors are installed, a small hardware equivalent to one dimension and a wide control area are provided. Will be realized.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In this embodiment, by installing a plurality of error detectors equidistant from the control speaker,
The transfer function from the control speaker to each error detector is equalized, and a wide control area can be realized with a small amount of hardware corresponding to one dimension.

In FIG. 4, 1 is a noise source and 2 is a noise source 1.
Control speakers 3a, 3b, 3c, installed near the
.., 3n are error detectors installed equidistant from the control speaker 2, 4 is an adder for adding the output of each error detector, 5
Is a subtractor, 6 is an FX filter having a characteristic equal to the sum of transfer functions from the control speaker to each error detector, 7 is an EC filter having a characteristic equal to the transfer function from the control speaker to the noise detector, 8 Is an adaptive filter, 9 is a coefficient updater, and 10 is a noise detector installed near the noise source 1.

The operation of this embodiment will be described below. The control sound of the control speaker 2 is applied to the noise emitted from the noise source 1, and its error sound is detected by the error detectors 3a to 3n,
The error detection signals are added by the adder 4 and input to the error input of the coefficient updater 9. On the other hand, the subtracter 5 subtracts the output signal of the EC filter 7 from the noise detection signal of the noise detector 10 and inputs the subtracted signal to the adaptive filter 8 and the FX filter 6 to
The output signal of the filter 6 is input to the reference input of the coefficient updater 9. The coefficient updater 9 performs a coefficient update operation by an LMS (Least Mean Square) algorithm or the like, and updates the coefficient of the adaptive filter 8 based on the operation result so that the error input signal is always small. Then, the output signal of the adaptive filter 8 in which the new coefficient is set is the control speaker 2
Is also input to the EC filter 7. Here, since the EC filter 7 has the above-mentioned characteristics, it is possible to cancel the acoustic feedback loop from each control speaker to the noise detector.

As described above, according to the configuration of this embodiment,
The control sound emitted from the control speaker is detected by a plurality of error detectors equidistant from each control speaker. At this time, the transfer functions from the control speaker to each error detector are all the same, and these By setting a characteristic equal to the sum of the functions in the FX filter 6 and a characteristic equal to the transfer function from the control speaker 2 to the noise detector 10 in the EC filter 7, an arbitrary plurality of error detectors are installed. Even in such a case, a wide control area can be realized with a small amount of hardware corresponding to one dimension.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, one error detector is installed near each of a plurality of control speakers installed equidistant from the noise detector, and the distance between each control speaker and the error detector is made equal. The transfer functions from the control speaker to the noise detector are equal to each other, and the transfer functions from the control speakers to the error detector are equal to each other, so that a wide control area can be realized with a small amount of hardware equivalent to one dimension. It has characteristics.

In FIG. 5, 1 is a noise source, 10 is a noise detector, 2a, 2b, 2c, ..., 2n are noise detectors 1.
Control speakers installed equidistant from 0, 3a, 3b, 3
c, ..., 3n are error detectors installed equidistantly in the vicinity of each control speaker, 4 is an adder for adding the outputs of the error detectors, 5 is a subtractor, and 6 is an error detector from the control speaker. FX set to a characteristic equal to the sum of each transfer function up to
A filter, 7 is an EC filter having a characteristic equal to the sum of transfer functions from the control speaker to the noise detector, 8 is an adaptive filter, and 9 is a coefficient updater.

The operation of this embodiment will be described below. The control speaker 2a, 2b, 2 is added to the noise emitted from the noise source 1.
.., 2n control sounds are applied, the error sounds are detected by the error detectors 3a to 3n, each error detection signal is added by the adder 4, and the result is input to the error input of the coefficient updater 9. . On the other hand, from the detection signal of the noise detector 10, the subtractor 5
The output signal of the filter 7 is subtracted to obtain the adaptive filter 8 and F
It is input to the X filter 6, and the output signal of the FX filter 6 is input to the reference input of the coefficient updater 9. The coefficient updater 9 is L
A coefficient update operation is performed by an MS (Least Mean Square) algorithm or the like, and the coefficient of the adaptive filter 8 is updated by the operation result so that the error input signal is always small. Then, the output signal of the adaptive filter 8 for which a new coefficient is set is input to the control speaker 2 and the EC filter 7. Here, since the EC filter 7 has the above-mentioned characteristics, it is possible to cancel the acoustic feedback loop from each control speaker to the noise detector.

As described above, according to the configuration of this embodiment,
The control sound emitted from the control speaker is detected by a plurality of error detectors installed at equal distances in the vicinity of each control speaker. At this time, all transfer functions from the control speaker to each error detector are the same. Therefore, the characteristics equal to the sum of these transfer functions are set in the FX filter 6, and the characteristics equal to the sum of transfer functions from each control speaker to the noise detector 10 are set in the EC filter 7. Even when an arbitrary plurality of speakers and error detectors are installed, a wide control area can be realized with a small amount of hardware corresponding to one dimension.

Next, a sixth embodiment of the present invention will be described with reference to FIG. In this embodiment, a plurality of error detectors are installed in the vicinity of each of a plurality of control speakers installed equidistantly from the noise detector, and the distance between the control speaker and each error detector in the vicinity is set to each other. By making them equal, the transfer functions from the control speaker to the noise detector are made equal to each other, and the transfer functions from the control speaker to the respective error detectors are made equal to each other, so that a small amount of hardware equivalent to one dimension can be used. It has a feature that can realize a control area.

In FIG. 6, 1 is a noise source, 10 is a noise detector, 2a, 2b, 2c, ..., 2n are noise detectors 1.
Control speakers 3aa, 3a installed equidistant from 0
, 3an are error detectors installed equidistant from the control speaker 2a, similarly 3na, 3nb ,.
nm is an error detector installed equidistantly from the control speaker 2n, 4a, 4b, ..., 4n, 4 is an adder for adding the outputs of the error detectors, 5 is a subtracter, and 6 is an error from the control speaker. FX filter set to a characteristic equal to the sum of transfer functions to the detector, 7 an EC filter set to a characteristic equal to the sum of transfer functions from the control speaker to the noise detector, 8 an adaptive filter, 9 a coefficient It is an updater.

The operation of this embodiment will be described below. The control speaker 2a, 2b, 2 is added to the noise emitted from the noise source 1.
The control sounds of c, ..., 2n are applied, and the error sound is detected by the error detectors 3a to 3 nm, and the adders 4a, 4b ,.
.., 4n, 4 add the respective error detection signals and input to the error input of the coefficient updater 9. On the other hand, the subtractor 5 subtracts the output signal of the EC filter 7 from the detection signal of the noise detector 10 and inputs the subtracted signal to the adaptive filter 8 and FX filter 6,
The output signal of the X filter 6 is input to the reference input of the coefficient updater. The coefficient updater 9 performs a coefficient update operation by an LMS (Least Mean Square) algorithm or the like, and updates the coefficient of the adaptive filter 8 based on the operation result so that the error input signal is always small. Then, the output signal of the adaptive filter 8 in which the new coefficient is set is the control speaker 2
Is also input to the EC filter 7. Here, since the EC filter 7 has the above-mentioned characteristics, it is possible to cancel the acoustic feedback loop from each control speaker to the noise detector.

As described above, according to the configuration of this embodiment,
The control sound emitted from the control speaker is detected by a plurality of error detectors installed equidistantly in the vicinity of each control speaker. At this time, all transfer functions from the control speaker to each error detector are the same. By setting a characteristic equal to the sum of these transfer functions in the FX filter 6, and a characteristic equal to the sum of transfer functions from each control speaker to the noise detector 10 in the EC filter 7, Even if any plural error detectors are installed, a wide control area can be realized with a small amount of hardware corresponding to one dimension.

[0037]

As is apparent from the above description, according to the present invention, the control speaker and the respective error detectors are equidistant from each other, and the transfer function from the control speaker to each error detector is set. Are set equal to each other, and the sum of the transfer functions is set in the filtered X filter and the echo cancellation filter, and the distance between the noise detector and each control speaker is equidistant. It is possible to realize a wide control area with a small amount of hardware corresponding to one dimension by setting the same transfer functions up to and setting the sum of each transfer function in the echo cancellation filter.

[Brief description of drawings]

FIG. 1 is a block diagram of a noise control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a noise control device according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a noise control device according to a third embodiment of the present invention.

FIG. 4 is a block diagram of a noise control device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram of a noise control device according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram of a noise control device according to a sixth embodiment of the present invention.

FIG. 7 is a block diagram of a conventional noise control device.

[Explanation of symbols]

 1 Noise Source 2, 2a, 2b, 2c, ..., 2n Control Speaker 3a, 3b, 3c, ..., 3n Error Detector 4, 4a, 4b, ..., 4n Adder 5 Subtractor 6 Filter De-X filter 7 Echo cancellation filter 8 Adaptive filter 9 Coefficient updater 10 Noise detector

Claims (6)

[Claims] 1. A control speaker installed near a noise source,
A plurality of error detectors installed equidistant from the control speaker, an adder for adding the outputs of the error detectors, and a subtractor for subtracting the output of the adder and the output of the second filter, An adaptive filter and a first filter that receive the output of the subtractor, a coefficient updater that receives the output of the first filter and the output of the subtractor, and a second filter that receives the output of the adaptive filter. A filter, the coefficient of the adaptive filter is updated according to the output of the coefficient updater, the output of the adaptive filter is input to the control speaker, and the characteristics of the first filter and the second filter are set. A noise control device characterized by making the sum of transfer functions from a control speaker to each error detector equal. 2. A plurality of control speakers installed in the vicinity of a noise source, an error detector installed in the vicinity of each control speaker at an equal distance, and an adder for adding the outputs of the error detectors. A subtractor for subtracting the output of the adder and the output of the second filter; an adaptive filter and a first filter for inputting the output of the subtractor; an output of the first filter and the subtraction; Coefficient updater that inputs the output of the
A second filter for inputting the output of the adaptive filter, updating the coefficient of the adaptive filter according to the output of the coefficient updater, inputting the output of the adaptive filter to each control speaker, and A noise control device characterized in that the characteristics of the first filter and the second filter are made equal to the sum of the transfer functions from the control speaker to the error detector installed in the vicinity thereof. 3. A plurality of control speakers installed in the vicinity of a noise source, a plurality of error detectors installed in the vicinity of each control speaker at equal distances, and an adder for adding the outputs of the error detectors. , A subtractor for subtracting the output of the adder and the output of the second filter, an adaptive filter and a first filter for inputting the output of the subtractor, an output of the first filter and the subtractor A coefficient updater for inputting the output of the adaptive filter and the second filter for inputting the output of the adaptive filter, and update the coefficient of the adaptive filter according to the output of the coefficient updater The output is input to each control speaker, the distance between the control speaker and each error detector in the vicinity thereof is made equal to each other for each control speaker, and the characteristics of the first filter and the second filter are set in the vicinity of the control speaker. Each mistake A noise control device characterized in that it is equal to the sum of transfer functions up to a difference detector. 4. A noise detector for detecting information of a noise source, a control speaker installed in the vicinity of the noise source, a plurality of error detectors installed equidistant from the control speaker, and each of the error detectors. An adder for adding the outputs, and a subtractor for subtracting the output of the noise detector and the output of the second filter,
Adaptive filter and first filter for inputting output of the subtractor, coefficient updater for inputting output of the first filter and output of adder, and second filter for inputting output of the adaptive filter And updating the coefficient of the adaptive filter according to the output of the coefficient updater and inputting the output of the adaptive filter to a control speaker, and setting the characteristics of the first filter from the control speaker to each error detector. And a characteristic of the second filter equal to the transfer function from the control speaker to the noise detector. 5. A noise detector for detecting information of a noise source, a plurality of control speakers installed equidistant from the noise detector, and an error installed one equidistant from each control speaker in the vicinity of each control speaker. A detector, an adder for adding the outputs of the error detectors, a subtractor for subtracting the output of the noise detector and the output of the second filter, and an adaptive filter for inputting the output of the subtractor, The output of the coefficient updater includes a first filter, a coefficient updater for inputting the output of the first filter and an output of the adder, and the second filter for inputting the output of the adaptive filter. According to the above, the coefficient of the adaptive filter is updated, the output of the adaptive filter is input to the control speaker, and the characteristics of the first filter are summed up of transfer functions from the control speaker to the error detector installed in the vicinity thereof. Equal to and before A noise control device characterized in that the characteristic of the second filter is made equal to the sum of the transfer functions from each control speaker to the noise detector. 6. A noise detector for detecting information of a noise source, a plurality of control speakers installed equidistant from the noise detector, and a plurality of error detectors installed equidistantly in the vicinity of each control speaker. , An adder for adding the outputs of the respective error detectors, a subtractor for subtracting the output of the noise detector and the output of the second filter, an adaptive filter for inputting the output of the subtractor, and 1 filter, a coefficient updater for inputting an output of the first filter and an output of an adder, and a second filter for inputting an output of the adaptive filter, and an output of the coefficient updating unit. Accordingly, the coefficient of the adaptive filter is updated, the output of the adaptive filter is input to the control speaker, and the distances between the control speaker and each error detector in the vicinity thereof are made equal to each other for each control speaker. Control the characteristics of Noise that is equal to the sum of transfer functions from the control speaker to each error detector in the vicinity thereof, and the characteristic of the second filter is equal to the sum of transfer functions from each control speaker to the noise detector. Control device.