JP2012023416A - Noise reduction system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noise reduction system capable of obtaining high noise reduction efficiency using general-purpose headphones when providing information such as voice service to a user who takes a seat in a cabin of an airplane and a railway vehicle where noise is made.SOLUTION: When video and voice content data inputted from a server 109 are played by a sheet monitor 101a, a sound detected by a microphone 201 of a handset 103 is treated as a noise by internal software. The noise data inputted through noise input means 305 from the microphone 201 of the handset 103 is converted into noise control data which has a phase opposite to that of the noise data by antiphase generation means 306, is synthesized with the voice data, where voice compression data is decoded by voice decoding means 303, by synthesis means 307, and is output from voice output means 308 to headphones 105.

Description

  The present invention relates to a noise reduction system, and more particularly to a noise reduction system used in a cabin of an aircraft, a railway vehicle, or the like.

  When providing information such as a voice service to a user who is seated in an aircraft or a railway vehicle using headphones or a speaker, it is difficult to hear the voice due to noise, which hinders the voice service.

  In particular, in the case of aircraft, noise from equipment for generating aircraft thrust, mainly propellers and engines, and noise related to airflow, such as wind noise during flight, are the main noise sources. Since noise causes discomfort to passengers and hinders voice services, improvement is desired.

  In order to reduce the noise by the active attenuation means, conventionally, a method of generating a sound wave having a phase opposite to the noise phase has been generally implemented. With this method, the noise level can be reduced.

  Examples of specific applications include a microphone attached to headphones that detects sound generated from a noise source, a controller that amplifies the signal input from the microphone and inverts the phase, and an electrical signal input from the controller There has been proposed a noise reduction device including a headphone that converts a sound into sound and transmits the sound (see, for example, Patent Document 1).

  There has also been proposed a method in which a sound player includes a microphone that detects sound generated from a noise source (see, for example, Patent Document 2). In Patent Document 2, a sign opposite to noise measured by a microphone is generated by an active noise canceling unit, and the generated signal is synthesized with speech and then output from headphones. With this configuration, it is possible to obtain a noise reduction effect using a general headphone.

  FIG. 2 is a schematic configuration diagram showing an entertainment system that provides information such as video and audio services in an aircraft.

  Note that MPEG2-TS defined by ISO / IEC13818-1 is used as the transmission format of video data and audio data used, and Ethernet (registered trademark) defined by the IEEE 802.3 standard is used as a network used for distribution. An example is shown.

  In FIG. 2, 100a and 100b are seats in the aircraft. A seat monitor 101a is installed on the back of the seat 100a and displays various menus on a display (not shown) and outputs video and audio. Reference numeral 102 denotes a user (aircraft passenger).

  Reference numeral 103 denotes an operation handset installed on the seat 100b, which is used for control operations such as selection of video and audio to be reproduced on the seat monitor 101a, volume adjustment, and a call function using a built-in microphone and speaker. The handset 103 is normally held at the armrest position of the seat and is connected to the seat monitor 101a by the cable 104.

  FIG. 3 is a schematic configuration diagram of the handset 103. The handset 103 includes a speaker 200 and a microphone 201 for realizing a call function with another handset, and buttons 202a to 202c for performing various operations such as video / audio reproduction or stop, reading lamp lighting, and attendant call. ing.

  The handset 103 transmits various operation commands and audio data via the cable 104 when transmitting data to the sheet monitor 101 a. Also, voice input from the handset 103 is transmitted to a predetermined communication destination via the sheet monitor 101a, the sheet box 107a, and the network.

  Returning to FIG. 2, reference numeral 105 denotes headphones worn by the user 102.

  The headphone 105 is connected to the seat monitor 101a with a cable 106 and outputs sound. Although not shown, the handset 103 and the headphone 105 are similarly arranged on the seat 100a.

  In FIG. 2, the cable 104 and the cable 106 are floated in a hollow state for easy understanding, but actually, they are wired from the seat 100 b to the seat 100 a through the floor.

  Reference numerals 107a and 107b denote sheet boxes that operate as Ethernet (registered trademark) switches in the relay devices of the sheet monitors 101a and 101b, respectively. The seat box 107a is installed under the seat 100a, is connected to the seat monitor 101a via the Ethernet (registered trademark) cable 108, and transmits data as an Ethernet (registered trademark) switch.

  Reference numeral 109 denotes a server that holds contents such as video and audio and manages the entire system. The server 109 is daisy chain connected to the sheet boxes 107a and 107b via the Ethernet (registered trademark) cable 110, and distributes contents to the sheet monitors 101a and 101b via the sheet boxes 107a and 107b. An Ethernet (registered trademark) cable 110 is also wired under the floor.

  In the above configuration, the noise detection microphone 111 is attached to the upper part of the seat monitor 101 a, and the detected ambient noise is synthesized with the audio data of the content inside the seat monitor 101 a and output to the headphones 105 via the cable 106. Is done.

  Next, processing inside the sheet monitor 101a will be described. FIG. 4 is a functional configuration diagram of the sheet monitor 101a.

  In FIG. 4, 300 is an input means for compressed video / audio data MPEG2-TS, 301 is a means for separating video / audio compressed data, 302 is a video decoding means for decoding MPEG compressed video data, and 303 is MPEG audio compressed data. 306 is a display means for decoding decoded video data, 305 is an input means for noise data, 306 is an anti-phase generation means for converting noise data into noise control data, and 307 is audio data and noise control data. 308 is a voice output means for outputting the synthesized voice, 309 is a voice input means for the call from the handset 103, 310 is a voice encoding means for converting the voice to voice compression data, and 311 is a voice compression. A network that sends data to other handsets over the network Click, which is the transmission means.

  The internal processing of the seat monitor in the entertainment system configured as described above will be described.

  MPEG2-TS data, which is video / audio content input from the server 109 from the video / audio input means 300 of the sheet monitor 101a, is divided into video compression data and audio compression data by the video / audio separation means 301. After being decoded by the video decoding means 302, it is displayed on the display of the sheet monitor 101a by the video display means 304.

  On the other hand, the noise data input from the noise detection microphone 111 through the noise input unit 305 is converted into noise control data having an opposite phase to the noise data by the antiphase generation unit 306 and is compressed by the audio decoding unit 303. The audio data obtained by decoding the data is synthesized by the synthesizing unit 307 and output from the audio output unit 308 to the headphones 105.

  The voice input from the handset 103 via the voice input unit 309 is converted into voice compression data by the voice encoding unit 310 and then transmitted from the network transmission unit 311 to the other party's handset via the network. The

  FIG. 5 is a schematic configuration diagram showing another example of the entertainment system. In FIG. 5, the same functions as those in FIG.

  A difference from the entertainment system of FIG. 2 is that a handset 103 and a headphone 105 are connected to a seat monitor 101b.

  In this case, a video of content such as video / audio distributed from the server 109 is displayed on the sheet monitor 101a, and the audio is output via the sheet monitor 101b.

  When transmitting data from the handset 103 to the sheet monitor 101a, various operation commands and audio data are transmitted via the sheet monitor 101b and the sheet boxes 107b and 107a. Voice input from the handset 103 is transmitted to the handset of the other party of communication via the seat monitor 101b, the seat box 107b, and the network.

  The noise detecting microphone 111 is attached to the upper part of the sheet monitor 101 b, and the detected noise is synthesized with the audio data of the content inside the sheet monitor 101 b and output to the headphones 105 via the cable 106.

  FIG. 6 is a functional configuration diagram of the sheet monitors 101a and 101b in the above configuration. The difference from FIG. 4 is that MPEG2-TS data, which is video / audio content input from the video / audio input means 300 of the sheet monitor 101a from the server 109, is compressed by the video / audio separation means 301 with video compression data and audio compression data. The video compression data is decoded by the video decoding means 302 and then displayed on the display of the sheet monitor 101a by the video display means 304. The audio compression data is decoded by the audio decoding means 303 and then the network. It is a point sent from the transmission means 312 to the sheet monitor 101b via the network.

  The noise data input from the noise detection microphone 111 of the seat monitor 101b via the noise input unit 305 is converted into noise control data having an opposite phase of the noise data by the anti-phase generation unit 306, and the network reception unit. The voice data from the sheet monitor 101 a received at 313 is synthesized by the synthesizing unit 307 and output from the voice output unit 308 to the headphones 105.

  Similarly to FIG. 2, the call voice input inputted from the handset 103 via the voice input means 309 is converted into voice compressed data by the voice encoding means 310 and then sent from the network transmission means 311 via the network to the other party. Sent to the previous handset.

  By adopting the same method as in Patent Document 2 in each of the above configurations, a noise reduction effect can be obtained using a general headphone.

JP-A-2-252398 Special table 2007-500466 gazette

  However, in the configuration of Patent Document 1, it is necessary to provide a headphone with a microphone for noise detection and a control circuit for noise reduction. Therefore, the configuration becomes special, and the cost is lower than that of a general-purpose headphone. To increase.

  In addition, since it becomes heavier in weight, it is painful for passengers, and it is difficult to use especially on aircraft that can be used for a long time.

  Further, in the configuration of FIG. 2 using the same method as in Patent Document 2, the distance L1 between the noise detection microphone 111 and the passenger's headphone 105 is separated, and detection is performed by the microphone 111 due to the influence of reflection and attenuation of sound waves. There is a difference between the noise that is heard and the noise that the user 102 actually hears.

  For this reason, it is difficult to measure noise in an environment close to the vicinity of the user's 102 ear, and a sufficient noise reduction effect cannot be obtained.

  On the other hand, in the configuration of FIG. 5, since the microphone 111 is installed on the seat monitor 101 b installed on the back of the back of the seat where the user is seated in the aircraft, the backrest is shielded between the noise detection microphone 111 and the user 102. It becomes a thing. Due to the influence of reflection and attenuation of sound waves by the shielding object, a difference occurs between the noise detected by the microphone 111 and the noise that the user 102 actually hears.

  For this reason, it is difficult to measure noise in an environment close to the vicinity of the ear of the user 102 as in the configuration of FIG. 2, and a sufficient noise reduction effect cannot be obtained.

  The present invention solves the above-described conventional problems, and provides a noise reduction system capable of obtaining a high noise reduction effect while using a general-purpose headphone even under the restriction of arrangement in an aircraft or rail vehicle cabin. Objective.

  The noise reduction system of the present invention includes a voice output means, a call voice input means having a call function and a noise input function, and a voice processing means to which the voice output means and the call voice input means are connected. Generates noise control data for reducing noise from the noise data acquired by the call voice input means, and the voice processing means synthesizes the voice data input from the voice input means and the noise control data, and outputs the voice Output to the means.

  Further, the voice processing means does not use the noise input function and does not generate the noise control data when using the call function of the call voice input means.

  With this configuration, by using a microphone used as a call function for noise detection, ambient noise can be detected in the vicinity of the user, and sound can be heard in a state where a noise reduction effect can be obtained.

  According to the voice processing system of the present invention, noise is acquired by a microphone installed near the user for a call, and noise control is performed by the voice processing means, so that the arrangement within the cabin of the aircraft or the railway vehicle is limited. However, a high noise reduction effect can be obtained while using general-purpose headphones.

  Further, it can be realized only by adding an audio processing means to an existing video / audio distribution system, and no additional hardware is required, so that it can be easily applied to an existing system.

Functional configuration diagram of a seat monitor of a noise reduction system according to an embodiment of the present invention Schematic configuration diagram of in-flight entertainment system Schematic configuration diagram of handset Functional configuration diagram of seat monitor of conventional noise reduction system Schematic configuration diagram showing another example of an in-flight entertainment system Functional configuration diagram of a seat monitor showing another example of a conventional noise reduction system

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a functional configuration diagram of a seat monitor of a noise reduction system according to Embodiment 1 of the present invention, and constitutes a part of an in-flight entertainment system.

  In the present embodiment, the same components as those in the conventional example shown in FIG.

  The in-flight entertainment system to which this embodiment is applied is that the noise detecting microphone 111 is removed from the conventional configuration of FIG. In the present embodiment, noise detection is performed by the microphone 201 for realizing a call function with another handset provided in the handset 103.

  In FIG. 1, 300 is an input means for compressed video / audio data MPEG2-TS, 301 is a means for separating video / audio compressed data, 302 is a video decoding means for decoding MPEG video compressed data, and 303 is MPEG audio compressed data. 306 is a display means for decoding decoded video data, 306 is an anti-phase generation means for converting noise data into noise control data, 307 is a synthesis means for synthesizing voice data and noise control data, 308 is Voice output means for outputting synthesized voice, 309 is call voice from handset 103, noise input means, 310 is voice encoding means for converting call voice to voice compressed data, 311 is voice compressed data via network Network transmission means for transmitting to another handset. Reference numeral 314 denotes switching means for switching processing depending on whether the voice input from the microphone 201 of the handset 103 is a call voice or noise.

  The internal processing of the seat monitor according to the present embodiment in the entertainment system configured as described above will be described in different points from the conventional FIG. 2 and FIG.

  When the video / audio content data input from the server 109 in FIG. 2 is reproduced on the sheet monitor 101a, the sound detected by the microphone 201 of the handset 103 is generated by the software switching means inside the sheet monitor 101a. Are treated as

  Noise data input from the microphone 201 of the handset 103 via the noise input unit 305 is converted into noise control data having an opposite phase to the noise data by the anti-phase generation unit 306, and the audio compression unit 303 decodes the audio compression data. The synthesized voice data is synthesized by the synthesizing means 307 and outputted from the voice output means 308 to the headphones 105.

  When a call is made between the handset 103 and another handset, the sound detected by the microphone 201 is handled as a call voice by the software switching means inside the seat monitor 101a.

  The call voice input input from the microphone 201 of the handset 103 through the voice input unit 309 is converted into voice compression data by the voice encoding unit 310 and then transmitted from the network transmission unit 311 to the other party's handset via the network. Is done.

  The most important points in the present embodiment will be described.

  As shown in FIG. 2, the distance L1 between the seat monitor 101a that performs noise reduction processing and the ear of the user 102 is separated from the installation restriction of the equipment in the aircraft, but the configuration of the present embodiment allows the handset 103 to The distance L2 between the microphone 201 and the user's 102 ear is closer than the distance L1 between the seat monitor 101a and the user's 102 ear.

  With this configuration, it is possible to acquire the noise in the vicinity of the user using the microphone 201 of the handset 103, so that the noise is higher than when a microphone is installed on the seat monitor 101a while using general-purpose headphones. A reduction effect can be obtained.

  Also, in another example shown in FIG. 5 of the related art, by detecting noise with the microphone 201 of the handset 103, it is installed on the back of the back of the seat where the user is seated in the aircraft as in the configuration of FIG. When the microphone 111 is installed on the seat monitor 101b, the backrest between the noise detection microphone 111 and the user 102 becomes a shield, and the noise detected by the microphone 111 due to the influence of reflection and attenuation of sound waves. There is no difference between the noise actually heard by the user 102 and a higher noise reduction effect can be obtained compared to the case where a microphone is installed on the seat monitor 101b while using general-purpose headphones. Can do.

  Furthermore, when the noise reduction system of the present invention is applied to the example of FIG. 5, the handset 103 and the headphone 105 are connected to the seat monitor 101b, so that the wiring is compared with the example of FIG. 2 connected to the seat monitor 101a. This is effective in reducing cost and weight.

  In the present embodiment, whether the sound detected by the microphone 201 is a call voice or noise is switched by software inside the seat monitor 101a. Other methods such as pressing the button switch only when making a call to the handset 103 may be used.

  In the present embodiment, the seat monitor that reproduces the sound itself constitutes a part of the noise reduction system. However, for example, a part of the function of the noise system may be substituted for another device such as a seat box.

  Further, in the present embodiment, the description has been made on the video / audio distribution service in the aircraft, but the present invention can also be used when there is no video / audio distribution, that is, as a noise reduction system in a simple viewing system.

  The noise reduction system according to the present invention can obtain a high noise reduction effect while using a general-purpose headphone in an environment where the user's ear is separated from the device that performs the voice processing, and additionally performs the voice processing. Even in an environment where there is a shield between the device and the user's ear, it is possible to obtain a high noise reduction effect while using general-purpose headphones. Yes, it is useful in environments where there are shielding objects inside.

100a, 100b Seat 101a, 101b Seat monitor 102 User (passenger)
103 Handset 104, 106 Cable 105 Headphone 107a, 107b Seat box (relay machine)
108, 110 Ethernet (registered trademark) cable 109 Server 200 Speaker 201 Microphone 202a to 202c Operation buttons 300 Video / audio input means 301 Video / audio separation means 302 Video decoding means 303 Audio decoding means 304 Display means 305 Noise input means 306 Reverse Phase generation means 307 Synthesis means 308 Audio output means 309 Audio input means 310 Audio encoding means 311 Network transmission means

Claims (5)

Audio output means;
A call voice input means having a call function and a noise input function;
Voice processing means to which the voice output means and the call voice input means are connected;
With
The noise reduction system, wherein the voice processing means generates noise control data for reducing noise from the noise data acquired by the call voice input means and outputs the noise control data from the voice output means. Voice input means connected to the voice processing means,
The noise reduction system according to claim 1, wherein the voice processing unit synthesizes voice data input from the voice input unit and the noise control data, and outputs the synthesized data from the voice output unit. 2. The noise reduction system according to claim 1, wherein the voice processing means does not use a noise input function and does not generate the noise control data when the call function of the call voice input means is used. A video / audio playback device for playing back content such as video and audio;
A speaker connected to the video / audio reproduction device;
An operation terminal connected to the video / audio reproduction device and operating the video / audio reproduction device;
The operation terminal has a call function and detects ambient noise when the call function is not used.
The video / audio reproduction device generates noise control data for reducing the noise from the detected noise, synthesizes it with audio data of the content to be reproduced, and outputs it from the speaker . The video / audio reproduction device is a seat monitor installed on the back of a seat back,
The noise reduction system according to claim 4, wherein the speaker is a headphone connected to the seat monitor.