JPH0937380A - Noise control type head set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain natural talking even in a high noise environment by talking back a sound signal obtained by reducing noise mixed into a speaking microphone through an adaptive filter to a speaker himself (or herself) and transmitting the sound signal to an opposite communication party, to prepare a margin for the operation time of the adaptive filter by an acoustic filter even at the time of detecting an adjacent noise and to attain noise control by less hardware parts. SOLUTION: This noise control type head set is provided with a noise detector 1 arranged on the outer wall of a head set, 1st and 2nd adaptive filters 3, 4 for inputting an output signal from the detector 1, a speaking microphone 10 arranged in the vicinity of a speaker's mouth, and error detectors 8, 9 arranged in the inwall of the head set. The output signal of the filter 3 is subtracted from the output of the microphone 10, the coefficient of the filter 3 is updated so that the subtraction signal is reduced and the coefficient of the filter 4 is updated so that the output signal of the detector 1 is reduced. Then the output signal of the filter 4, the subtraction signal and a received signal from a communication equipment are mutually added and the added signal is inputted to the speakers 6, 7 to output the subtraction signal as an output signal to be sent to the communication equipment.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In recent years, there has been proposed an active noise control type headset which silences environmental noise by controlling sound from a speaker.

Conventionally, a noise control type headset of this type generally has a structure shown in FIG. The configuration will be described below with reference to FIG. In the figure, the output signal of the error detector 8 of the headset 13 is processed by the gain phase adjuster 23, a control sound is emitted from the control speaker 6, and is negatively fed back to the error detector 8.
On the other hand, the signal from the reception signal input terminal 11 from the communication device is added to the output of the gain phase adjuster 23 and is output from the speaker 6. The same applies to the other channel. The detection signal of the transmitting microphone 10 is the transmission output terminal 12 for the communication device.
Is output to

[0004]

However, in the above-mentioned conventional noise control type headset, noise cannot be distinguished from the person's voice when talking with the other party using the communication device in a noisy environment. However, there was a problem in that it was difficult to hear the call, and noise was mixed in the transmitting microphone, making it difficult for the communication partner to hear the call.

[0005] The present invention is to solve the above problems,
It is an object of the present invention to provide a noise control type headset that can hear the voice of the person himself / herself even in a noisy environment and can reduce the influence of noise on the communication partner.

[0006]

In order to achieve the above-mentioned object, the present invention firstly provides a noise detector installed on the outer wall of a headset, and first and second inputting an output signal of the noise detector. 2 has an adaptive filter, a transmitting microphone installed near the mouth of the speaker, a control speaker installed on the inner wall of the headset, and an error detector installed on the inner wall of the headset. The output signal of the first adaptive filter is subtracted from the output signal of the talking microphone, the coefficient of the first adaptive filter is updated so that the subtracted signal becomes smaller, and the output signal of the error detector becomes smaller so as to become smaller. The coefficient of the second adaptive filter is updated, the output signal of the second adaptive filter, the subtraction signal and the reception signal from the communication device are added, and the result is input to the control speaker, and the subtraction signal is transmitted to the communication device. It becomes a speech output signal.

Second, a noise detector installed outside the headset, and the first, which inputs the output signal of the noise detector,
And a second adaptive filter, a transmitting microphone installed near the mouth of the speaker, a control speaker installed inside the headset, an error detector installed inside the headset, and a headset. Between the outer side and the inner side of the speaker and an ear pad portion, and subtracts the output signal of the first adaptive filter from the output signal of the transmitting microphone to reduce the subtracted signal. The coefficient of the filter is updated and the second signal is adjusted so that the output signal of the error detector becomes smaller.
Of the adaptive filter, the output signal of the second adaptive filter, the subtraction signal, and the reception signal from the communication device are added, and the result is input to the control speaker, and the subtraction signal is transmitted to the communication device. The output signal is formed by filling the acoustic filter with a gel buffer material.

[0008]

The present invention reduces the noise mixed in the transmitting microphone by the first adaptive filter having the above-mentioned structure, and the voice of the person is talked back by making it sound from the speaker, and the noise is also reduced. Since the voice is transmitted to the communication partner, both parties of communication can make a natural call.

[0009]

Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described with reference to FIG. The present embodiment is characterized in that the noise mixed in the transmitting microphone is reduced, and the talkback of the voice of the person concerned and the intelligibility of the communication partner are improved. In the figure,
1, 2 are noise detectors, 3, 4, 5 are adaptive filters, 6,
Reference numeral 7 is a control speaker, 8 and 9 are error detectors, 10 is a transmitting microphone, 11 is a receiving signal input terminal, 12 is a transmitting signal transmitting terminal, and 13 is a headset. The noise detector 1 is installed on the outer wall of the headset and detects noise coming from the outside. The adaptive filter 3 processes the noise detection signal and outputs a control output to the control speaker 6 inside the headset.
On the other hand, the error detector 8 outputs an error sound that is a combination of the noise that has entered the inside of the headset from the outside and the control sound of the control speaker.
And the LMS so that this error detection signal becomes small.
The coefficient of the adaptive filter 3 is adjusted by the (Least Mean Square) method or the like. This reduces the noise inside the headset. The same applies to the other channel. The noise detection signal is also input to the adaptive filter 5, and its processed output signal is transmitted to the transmitting microphone 1.
Subtract from the detection signal of 0. With this subtraction signal, the coefficient of the adaptive filter 5 is adjusted in the same manner as above. As a result, the noise contained in this transmission signal is reduced, and the S
The N ratio is improved. The subtracted signal is added to the control output signal of the adaptive filter as described above together with the received signal and sounded from the control speaker 6, so that the voice of the person is talked back, and the person can talk naturally even in a noisy environment. By inputting this subtraction signal to the transmitting terminal of the communication device, the communication partner also has a high degree of intelligibility, which improves the quality of the call.

The second embodiment of the present invention will be described below with reference to FIG. In addition to the features of the first embodiment, the present embodiment increases the calculation time of the adaptive filter by lengthening the time during which noise from the outside is transmitted to the inside of the headset by using an acoustic filter, thus increasing the hardware scale. There is a feature that can be reduced. In the figure, reference numeral 14 indicates a noise entry path, and 15 indicates an acoustic filter between the outer wall and the inside of the headset. This acoustic filter is realized by, for example, a bag-shaped structure filled with a gel silicon material.
Since this acoustic filter passes through the sound-vibration-sound conversion system, it is possible to obtain a large propagation delay of noise as compared with the propagation velocity of sound waves in the space of the normal air, and the calculation time of the adaptive filter 3 is increased. Therefore, the amount of hardware for realizing the adaptive filter 3 can be reduced. Further, since this acoustic filter attenuates high-frequency components of noise and the frequency band required for noise control can be set low, the sampling frequency of the digital circuit constituting the adaptive filter 3 can be reduced, and the time for calculating one sample can be reduced. The hardware size can also be reduced by increasing the margin.

[0011]

As is apparent from the above embodiments, according to the present invention, the noise mixed in the transmitting microphone is reduced by the adaptive filter, and the voice of the person is talked back by making it sound from the speaker. Similarly, since the voice with reduced noise is transmitted to the communication partner, both communication can make a natural call. Further, the acoustic filter can reduce the hardware scale of the adaptive filter.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional noise control type headset.

[Explanation of symbols]

 1, 2 Noise detector 3, 4, 5 Adaptive filter 6, 7 Control speaker 8, 9 Error detector 10 Transmitting microphone 11 Received signal input terminal 12 Transmitted signal output terminal 13 Headset 14 Noise entry path 15 Acoustic filter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H04R 1/10 101 G10K 11/16 H (72) Inventor Akinori Fujimoto 4 Komachi, Naka-ku, Hiroshima City, Hiroshima Prefecture No. 33 Chugoku Electric Power Co., Inc. (72) Inventor Nobuo Shimizu No. 4-33 Komachi, Naka-ku, Hiroshima City, Hiroshima Prefecture No. 33 Chugoku Electric Power Co., Inc. (72) Keiji Komori 4-33 Komachi, Naka-ku, Hiroshima City, Hiroshima Prefecture China Electric Power Company (72) Inventor Seiichi Amano 4-33 Komachi, Naka-ku, Hiroshima City, Hiroshima Prefecture

Claims (2)

[Claims] 1. A noise detector installed on the outer wall of a headset, and first and second inputting an output signal of the noise detector.
, An adaptive filter, a transmitting microphone installed near the mouth of the speaker, a control speaker installed on the inner wall of the headset, and an error detector installed on the inner wall of the headset. The output signal of the first adaptive filter is subtracted from the output signal of the microphone, the coefficient of the first adaptive filter is updated so that the subtracted signal becomes small, and the second signal is outputted so that the output signal of the error detector becomes small. Of the adaptive filter, the output signal of the second adaptive filter, the subtraction signal, and the reception signal from the communication device are added, and the result is input to the control speaker, and the subtraction signal is transmitted to the communication device. A noise control type headset characterized by being an output signal. 2. A noise detector installed on the outer wall of the headset, and first and second inputting an output signal of the noise detector.
An adaptive filter, a transmitting microphone installed near the mouth of the speaker, a control speaker installed inside the headset, and an error detector installed inside the headset,
An acoustic filter is provided between the outer side and the inner side of the headset and on the ear pad portion, and the first signal is output from the output signal of the transmitting microphone.
The output signal of the adaptive filter of is subtracted, and the coefficient of the first adaptive filter is updated so that the subtracted signal becomes smaller,
The coefficient of the second adaptive filter is updated so that the output signal of the error detector becomes small, and the output signal of the second adaptive filter, the subtraction signal, and the reception signal from the communication device are added,
A noise control type headset, which is input to a control speaker, the subtraction signal is used as a transmission output signal to a communication device, and the acoustic filter is filled with a gel buffer material.