JPH071959B2 - Sound pickup device - Google Patents
Sound pickup deviceInfo
- Publication number
- JPH071959B2 JPH071959B2 JP61229019A JP22901986A JPH071959B2 JP H071959 B2 JPH071959 B2 JP H071959B2 JP 61229019 A JP61229019 A JP 61229019A JP 22901986 A JP22901986 A JP 22901986A JP H071959 B2 JPH071959 B2 JP H071959B2
- Authority
- JP
- Japan
- Prior art keywords
- sound
- microphone
- rectifying
- amplitude
- smoothing circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Circuit For Audible Band Transducer (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は遠距離音源に対して感度が高く、撮影者音声あ
るいは風雑音のような近距離音源に対して感度の低い、
ビデオカメラ用収音装置に関するものである。TECHNICAL FIELD The present invention has high sensitivity to a long-distance sound source and low sensitivity to a short-distance sound source such as a photographer's voice or wind noise.
The present invention relates to a sound pickup device for a video camera.
従来の技術 近年、ビデオカメラの普及が目ざましい。このビデオカ
メラでの録画で問題となるのが、撮影者音声、カメラ操
作音のような、収音装置の近傍の撮影を目的としない音
源（以下近距離音源という）からの音が大きく録音され
ることである。そこで、1m程度以上はなれた撮影対照物
（以下遠距離音源という）からの音に対しては感度が高
く、近距離音源からの音に対しては感度が低いマイクロ
ホンが要望されている。従来はこの制御を、出力信号振
幅を一定に制御する自動ゲインコントロールすなわちAG
Cを用いて行っていた。2. Description of the Related Art In recent years, the spread of video cameras has been remarkable. The problem with recording with this video camera is that a large amount of sound from a sound source (hereinafter referred to as a short-distance sound source) that is not intended for shooting in the vicinity of the sound collecting device, such as the voice of the photographer or the sound of camera operation, is recorded. Is Rukoto. Therefore, there is a demand for a microphone that has a high sensitivity to a sound from a shooting contrast object (hereinafter referred to as a long-distance sound source) separated by about 1 m or more and a low sensitivity to a sound from a short-distance sound source. Conventionally, this control is based on automatic gain control, that is, AG
I was using C.
第３図は、この種の従来の収音装置のブロック図を示す
ものである。FIG. 3 is a block diagram of a conventional sound collecting device of this type.
第３図において、31は前方に指向性軸を向けた単一指向
性のマイクロホン、32はこのマイクロホン31の出力信号
の振幅を計算する整流平滑回路、33はこの整流平滑回路
32の出力により利得が制御される可変利得増幅回路であ
る。この整流平滑回路32と可変利得増幅回路33とでAGC
を構成している。In FIG. 3, 31 is a unidirectional microphone whose directional axis is directed forward, 32 is a rectifying / smoothing circuit for calculating the amplitude of the output signal of this microphone 31, and 33 is this rectifying / smoothing circuit.
This is a variable gain amplifier circuit whose gain is controlled by the output of 32. The rectifying / smoothing circuit 32 and the variable gain amplifying circuit 33 make the AGC
Are configured.
以上のように構成された収音装置について、以下その動
作を第４図，第５図を使用して説明する。The operation of the sound collecting device configured as described above will be described below with reference to FIGS. 4 and 5.
尚、第４図の遠距離音源A0,撮影者B0,スイッチC0の３つ
の音源からの音が、マイクロホン31に入射したとする。It is assumed that sounds from the three sound sources of the long-distance sound source A 0 , the photographer B 0 , and the switch C 0 in FIG. 4 are incident on the microphone 31.
第５図において、51はマイクロホン31の出力信号波形、
52は整流平滑回路32の出力信号波形、53は可変利得増幅
回路33の出力信号波形を示す。第５図中の記号A,B,Cは
第４図の音源の記号A0,B0,C0に対応し、対応する音源か
ら入射音であることを示す。In FIG. 5, 51 is an output signal waveform of the microphone 31,
Reference numeral 52 denotes an output signal waveform of the rectifying / smoothing circuit 32, and 53 denotes an output signal waveform of the variable gain amplifying circuit 33. The symbols A, B, C in FIG. 5 correspond to the symbols A 0 , B 0 , C 0 of the sound source in FIG. 4, and indicate that they are incident sounds from the corresponding sound sources.
第５図の出力信号51のままでは、遠距離音源からの音Ａ
が小さく、近距離音源（B0,C0）からの音B,Cが大きく録
音され、非常に聞き苦しい録音となる。そこで、この出
力信号51の振幅を第３図の整流平滑回路32で計算し、計
算結果52を可変利得増幅回路33に送る。可変利得増幅回
路33では、整流平滑回路32の出力信号が大きいほど利得
が低くなるように利得を制御する。その結果、出力信号
53が得られる。遠距離音源からの音も近距離音源からの
音も同じ大きさに調節され、明瞭度が向上する。If the output signal 51 shown in FIG.
Is small, and the sounds B and C from the short-distance sound source (B 0 , C 0 ) are recorded large, resulting in a very uncomfortable recording. Therefore, the amplitude of the output signal 51 is calculated by the rectifying / smoothing circuit 32 of FIG. 3, and the calculation result 52 is sent to the variable gain amplifying circuit 33. The variable gain amplifier circuit 33 controls the gain so that the larger the output signal of the rectifying / smoothing circuit 32, the lower the gain. As a result, the output signal
53 is obtained. The sound from the long-distance sound source and the sound from the short-distance sound source are adjusted to the same level, and the clarity is improved.
発明が解決しようとする問題点 しかしながら、上記のような構成では、第５図の出力信
号53の波形に示すように、近距離音源からの音が入射し
た直後は、収音装置の利得が下がってしまい、しばらく
の間、遠距離音源の音が小さく録音されてしまうという
欠点があった。これを改善するには、可変利得増幅回路
の時定数を短く設定する以外にはないが、短く設定する
と遠距離音源からの音の大小が圧縮されてしまい、不自
然な収音となってしまう。Problems to be Solved by the Invention However, in the above-described configuration, as shown in the waveform of the output signal 53 in FIG. 5, the gain of the sound collecting device decreases immediately after the sound from the short-distance sound source enters. However, for a while, the sound of a long-distance sound source was recorded as a small sound, which was a drawback. The only way to improve this is to set the time constant of the variable gain amplifier circuit to a short value, but if it is set to a short value, the volume of the sound from the long-distance sound source will be compressed, resulting in unnatural sound collection. .
本発明は上記問題点に鑑み、入射音の音源距離を検出
し、近距離音源からの音だけを減衰して、遠距離音源か
らの音を減衰させることなく収音できるように、近距離
音源に対する感度は低く、遠距離音源に対する感度は高
い収音装置を提供するものである。In view of the above problems, the present invention detects a sound source distance of an incident sound, attenuates only a sound from a short-distance sound source, and collects sound from a long-distance sound source without attenuating the sound. The sensitivity of the sound pickup device is low, and the sensitivity to a long-distance sound source is high.
これはビデオカメラのように、マイクロホンの近くで、
収音を目的としない音が発生する頻度の高い機器におい
ては、強く要望されている性能である。この収音を目的
としない近距離音源からの音としては、撮影者の音声，
ビデオカメラの操作音，風雑音，撮影機材の接触音等が
挙げられる。This is like a video camera, near a microphone,
This is a strongly demanded performance in a device in which a sound that is not intended for sound collection is frequently generated. The sound from the short-distance sound source, which is not intended to collect the sound, includes the voice of the photographer,
Examples include video camera operation noise, wind noise, and shooting equipment contact noise.
問題点を解決するための手段 この目的を達成するために、本発明の収音装置は、前方
に指向性軸を向けた単一指向性の主マイクロホンと、後
方に指向性軸を向けた単一指向性の副マイクロホンと、
この２つのマイクロホンの出力信号を加算する信号加算
器と、この信号加算器の出力信号の振幅を計算する加算
信号整流平滑回路と、前記主マイクロホンの出力信号の
振幅を計算する主マイク整流平滑回路と、前記副マイク
ロホンの出力信号の振幅を計算する副マイク整流平滑回
路と、前記主マイク整流平滑回路の出力と前記副マイク
整流平滑回路の出力とを加算する振幅加算器と、前記加
算信号整流平滑回路の出力と前記振幅加算器の出力との
振幅比を求める除算器と、主マイクロホンと出力端子と
の間に挿入されるところの、前記振幅比により利得が制
御される可変利得増幅回路とを具備した構成となってい
る。Means for Solving the Problems In order to achieve this object, a sound pickup device of the present invention has a unidirectional main microphone with a directional axis directed forward and a unidirectional main microphone with a directional axis directed backward. A unidirectional sub-microphone,
A signal adder for adding the output signals of the two microphones, an addition signal rectifying and smoothing circuit for calculating the amplitude of the output signal of the signal adder, and a main microphone rectifying and smoothing circuit for calculating the amplitude of the output signal of the main microphone. A sub microphone rectifying / smoothing circuit for calculating the amplitude of the output signal of the sub microphone, an amplitude adder for adding the output of the main microphone rectifying / smoothing circuit and the output of the sub microphone rectifying / smoothing circuit, and the added signal rectifier A divider for obtaining the amplitude ratio between the output of the smoothing circuit and the output of the amplitude adder; and a variable gain amplifier circuit whose gain is controlled by the amplitude ratio, which is inserted between the main microphone and the output terminal. It is configured to include.
作用 この構成により、入射音の音源距離を検出し、この検出
距離に応じて収音装置の感度を制御することで、距離感
を自由に制御できる。例えば、音源が近いほど感度を低
下させるようにすれば、撮影者の音声，風雑音，カメラ
の操作者等の混入が少ないビデオカメラ用の収音装置が
実現できる。すなわち、これ等の近距離音源からの音に
妨げられることなく、遠距離音源の音を高感度に収音で
きるようになる。Action With this configuration, the sense of distance can be freely controlled by detecting the sound source distance of the incident sound and controlling the sensitivity of the sound collecting device according to the detected distance. For example, if the sensitivity is lowered as the sound source is closer, a sound pickup device for a video camera can be realized in which the voice of the photographer, wind noise, and the operator of the camera are less mixed. That is, the sound of the long-distance sound source can be collected with high sensitivity without being disturbed by the sound from the short-distance sound source.
実施例 以下本発明の一実施例について、図面に参照しながら説
明する。Embodiment One embodiment of the present invention will be described below with reference to the drawings.
第１図は本発明の一実施例における収音装置のブロック
図を示すものである。FIG. 1 is a block diagram of a sound collecting device according to an embodiment of the present invention.
第１図において、１は前方に指向性軸を向けた単一指向
性の主マイクロホン、２は後方に指向性軸を向けた単一
指向性の副マイクロホン、３はこの２つのマイクロホン
の出力信号を加算する信号加算器、４はこの信号加算器
３の出力信号の振幅を計算する加算信号整流平滑回路、
５は主マイクロホン１と出力信号の振幅を計算する主マ
イク整流平滑回路、６は副マイクロホン２の出力信号の
振幅を計算する副マイク整流平滑回路、７は主マイク整
流平滑回路５の出力と副マイク整流平滑回路６の出力と
を加算する振幅加算器、８は加算信号整流平滑回路４の
出力と振幅加算器７の出力との振幅比を求める除算器、
９は主マイクロホン１と出力端子10との間に挿入される
ところの、この振幅比により利得が制御される可変利得
増幅回路である。In FIG. 1, 1 is a unidirectional main microphone whose directional axis is directed to the front, 2 is a unidirectional secondary microphone whose directional axis is directed to the rear, and 3 is the output signal of these two microphones. A signal adder for adding 4 and an addition signal rectifying / smoothing circuit for calculating the amplitude of the output signal of the signal adder 3,
5 is a main microphone rectifying and smoothing circuit for calculating the amplitude of the main microphone 1 and the output signal, 6 is a sub microphone rectifying and smoothing circuit for calculating the amplitude of the output signal of the sub microphone 2, and 7 is an output of the main microphone rectifying and smoothing circuit 5. An amplitude adder for adding the output of the microphone rectifying / smoothing circuit 6, a divider 8 for obtaining an amplitude ratio between the output of the addition signal rectifying / smoothing circuit 4 and the output of the amplitude adder 7,
Reference numeral 9 is a variable gain amplifier circuit which is inserted between the main microphone 1 and the output terminal 10 and whose gain is controlled by this amplitude ratio.
以上のように構成された収音装置について、以下その動
作について説明する。The operation of the sound collecting device configured as described above will be described below.
まず、従来例と同じく、第４図に示す音源から収音装置
に音が入射したとする。First, it is assumed that sound enters the sound collecting device from the sound source shown in FIG. 4, as in the conventional example.
第２図にこの時の各部の信号波形を示す。第２図におい
て、21は主マイクロホン１の出力信号波形、22は副マイ
クロホン２の出力信号波形、23は信号加算器３の出力信
号波形、24は加算信号整流平滑回路４の出力信号波形、
25は主マイク整流平滑回路５の出力信号波形、26は副マ
イク整流平滑回路６の出力信号波形、27は振幅加算器７
の出力信号波形、28は除算器８の出力信号波形、29は可
変利得増幅回路９の出力信号波形である。FIG. 2 shows the signal waveform of each part at this time. In FIG. 2, 21 is an output signal waveform of the main microphone 1, 22 is an output signal waveform of the sub microphone 2, 23 is an output signal waveform of the signal adder 3, 24 is an output signal waveform of the addition signal rectifying and smoothing circuit 4,
25 is the output signal waveform of the main microphone rectifying and smoothing circuit 5, 26 is the output signal waveform of the sub microphone rectifying and smoothing circuit 6, and 27 is the amplitude adder 7.
, 28 is an output signal waveform of the divider 8, and 29 is an output signal waveform of the variable gain amplifier circuit 9.
第２図中、A,B,Cの記号は第４図の音源の記号と対応し
ており、それぞれ音源A0,B0,C0からの入射音である。In FIG. 2, the symbols A, B, and C correspond to the symbols of the sound sources in FIG. 4, and are the incident sounds from the sound sources A 0 , B 0 , and C 0 , respectively.
まず、第２図の音源から音が入射し、第１図の主マイク
ロホン１と副マイクロホン２に、第２図の主マイクロホ
ン出力信号21,副マイクロホン出力信号22が発生する。
次に、この２つの信号を信号加算器３が加算し、加算信
号23を得る。加算信号整流平滑回路４は、この加算信号
23の振幅を計算し、加算信号振幅24を得る。First, sound is input from the sound source of FIG. 2, and the main microphone output signal 21 and the sub microphone output signal 22 of FIG. 2 are generated in the main microphone 1 and the sub microphone 2 of FIG.
Next, the signal adder 3 adds the two signals to obtain an addition signal 23. The added signal rectifying / smoothing circuit 4 uses the added signal.
The amplitude of 23 is calculated to obtain the added signal amplitude 24.
一方、主マイクロホンの出力信号21は、主マイク整流平
滑回路５に入力され、主マイクロホン振幅25を得る。副
マイクロホン出力信号22は、副マイク整流平滑回路６に
入力され、副マイクロホン振幅26を得る。この25,26の
振幅は振幅加算器７で加算されて、加算振幅27となる。
除算器８では、この加算振幅27を加算信号振幅24で除
し、振幅比28を得る。On the other hand, the output signal 21 of the main microphone is input to the main microphone rectifying and smoothing circuit 5, and the main microphone amplitude 25 is obtained. The sub microphone output signal 22 is input to the sub microphone rectifying / smoothing circuit 6 to obtain a sub microphone amplitude 26. The amplitudes of 25 and 26 are added by the amplitude adder 7 to obtain the added amplitude 27.
The divider 8 divides the added amplitude 27 by the added signal amplitude 24 to obtain the amplitude ratio 28.
この第２図の振幅比28から、遠距離音源からの音ではこ
の比が“1"となるが、近距離音源では“1"以上となるこ
とがわかる。これは、単一指向性マイクロホンと無指向
性マイクロホンの近接効果の相違に基づいている。From the amplitude ratio 28 in FIG. 2, it can be seen that this ratio is "1" for the sound from the long-distance sound source, but is "1" or more for the short-distance sound source. This is based on the difference in proximity effect between unidirectional and omnidirectional microphones.
すなわち、良く知られているように、無指向性マイクロ
ホンは近接効果を受けず、単一指向性マイクロホンは近
接効果を受ける。このため、単一指向性マイクロホンで
は、近距離音源に対する感度の方が遠距離音源に対する
感度より高くなる。一方、逆向きに配置した単一指向性
マイクロホンを加算したマイクロホンの指向性が、無指
向性となることは良く知られている事実である。したが
って、加算信号振幅24は近接効果を受けず、音源距離に
よって感度が変化していないが、加算振幅27は近接効果
を受けており、近距離音源に対する感度が上昇してい
る。このため上述したように、近距離音源では振幅比28
が“1"以上となる。That is, as is well known, omnidirectional microphones are not subject to proximity effects and unidirectional microphones are subject to proximity effects. For this reason, in the unidirectional microphone, the sensitivity to the short-distance sound source is higher than that to the long-distance sound source. On the other hand, it is a well known fact that the directivity of a microphone obtained by adding unidirectional microphones arranged in the opposite direction becomes omnidirectional. Therefore, the added signal amplitude 24 is not affected by the proximity effect and the sensitivity does not change depending on the sound source distance, but the added amplitude 27 is affected by the proximity effect and the sensitivity to the short-distance sound source is increased. Therefore, as mentioned above, the amplitude ratio 28
Is "1" or more.
そこで、この比に応じて可変利得増幅回路９で系の利得
を制御する。振幅比28が“1"の場合は、主マイクロホン
１の信号を減衰させずに外部に出力し、振幅比28が“1"
以上の場合には、減衰させて出力する。この出力信号を
29に示す。この出力信号29から、近距離音源に対する感
度が低下し、遠距離音源からの音を効率良く収音できる
ことがわかる。Therefore, the variable gain amplifier circuit 9 controls the gain of the system according to this ratio. When the amplitude ratio 28 is "1", the signal of the main microphone 1 is output to the outside without being attenuated, and the amplitude ratio 28 is "1".
In the above cases, the output is attenuated. This output signal
Shown in 29. From this output signal 29, it can be seen that the sensitivity to the short-distance sound source is reduced and the sound from the long-distance sound source can be efficiently collected.
以上示したように、本実施例によれば、主マイクロホン
１と、副マイクロホン２と、信号加算器３と、加算信号
整流平滑回路４と、主マイク整流平滑回路５と、副マイ
ク整流平滑回路６と、振幅加算器７と、除算器８と、可
変利得増幅回路９とから構成することにより、入射音の
音源距離に応じた感度制御が可能となる。さらに、撮影
者の音声，風雑音，カメラの操作音等が効果的に抑圧さ
れ、これ等の混入の少たい収音が可能となる。As described above, according to this embodiment, the main microphone 1, the sub microphone 2, the signal adder 3, the added signal rectifying / smoothing circuit 4, the main microphone rectifying / smoothing circuit 5, and the sub microphone rectifying / smoothing circuit. 6, the amplitude adder 7, the divider 8, and the variable gain amplifier circuit 9 enable sensitivity control according to the sound source distance of the incident sound. Furthermore, the voice of the photographer, wind noise, camera operation sound, and the like are effectively suppressed, and it is possible to collect sound with less mixing thereof.
発明の効果 本発明の収音装置は、入射音の音源距離を検出する機能
を有し、この検出距離に応じて収音装置の感度を制御す
ることにより、距離感を自由に制御できる。例えば、音
源が近いほど感度を低下させるようにすれば、撮影者の
音声，風雑音，カメラの操作音，機材の接触音等の混入
の少ないビデオカメラ用の収音装置が実現できる。すな
わち、これ等の近距離音源からの音に妨げられることな
く、遠距離音源の音を高感度に収音できるようになる。EFFECTS OF THE INVENTION The sound collecting device of the present invention has a function of detecting the sound source distance of the incident sound, and by controlling the sensitivity of the sound collecting device according to the detected distance, the sense of distance can be freely controlled. For example, if the sensitivity is lowered as the sound source is closer to the sound source, a sound pickup device for a video camera can be realized in which a photographer's voice, wind noise, camera operation sound, equipment contact sound, etc. are less mixed. That is, the sound of the long-distance sound source can be collected with high sensitivity without being disturbed by the sound from the short-distance sound source.
第１図は本発明の一実施例における収音装置のブロック
図、第２図は第１図の各部における信号の波形図、第３
図は従来の収音装置のブロック図、第４図は収音装置の
動作を説明するための各音源の配置図、第５図は第３図
の各部における信号の波形図である。 １……主マイクロホン、２……副マイクロホン、３……
信号加算器、４……加算信号整流平滑回路、５……主マ
イク整流平滑回路、６……副マイク整流平滑回路、７…
…振幅加算器、８……除算器、９……可変利得増幅回
路。FIG. 1 is a block diagram of a sound collecting device according to an embodiment of the present invention, FIG. 2 is a waveform diagram of signals in respective parts of FIG. 1, and FIG.
FIG. 4 is a block diagram of a conventional sound collecting device, FIG. 4 is a layout diagram of respective sound sources for explaining the operation of the sound collecting device, and FIG. 5 is a waveform diagram of signals in respective parts of FIG. 1 ... Main microphone, 2 ... Sub microphone, 3 ...
Signal adder, 4 ... Addition signal rectifying / smoothing circuit, 5 ... Main microphone rectifying / smoothing circuit, 6 ... Sub microphone rectifying / smoothing circuit, 7 ...
... Amplitude adder, 8 ... Divider, 9 ... Variable gain amplifier circuit.
Claims (1)
イクロホンと、後方に指向性軸を向けた単一指向性の副
マイクロホンと、この２つのマイクロホンの出力信号を
加算する信号加算器と、この信号加算器の出力信号の振
幅を計算する加算信号整流平滑回路と、前記主マイクロ
ホンの出力信号の振幅を計算する主マイク整流平滑回路
と、前記副マイクロホンの出力信号の振幅を計算する副
マイク整流平滑回路と、前記主マイク整流平滑回路の出
力と前記副マイク整流平滑回路の出力とを加算する振幅
加算器と、前記加算信号整流平滑回路の出力と前記振幅
加算器の出力との振幅比を求める除算器と、主マイクロ
ホンと出力端子との間に挿入されるところの、前記振幅
比により利得が制御される可変利得増幅回路とを具備し
てなる収音装置。1. A unidirectional main microphone having a directional axis directed to the front, a unidirectional sub microphone having a directional axis directed to the rear, and a signal for adding output signals of the two microphones. An adder, an addition signal rectifying / smoothing circuit for calculating the amplitude of the output signal of the signal adder, a main microphone rectifying / smoothing circuit for calculating the amplitude of the output signal of the main microphone, and an amplitude of the output signal of the sub microphone. Sub microphone rectifying / smoothing circuit for calculating, amplitude adder for adding output of the main microphone rectifying / smoothing circuit and output of the sub microphone rectifying / smoothing circuit, output of the addition signal rectifying / smoothing circuit and output of the amplitude adder And a variable gain amplifying circuit whose gain is controlled by the amplitude ratio, which is inserted between a main microphone and an output terminal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61229019A JPH071959B2 (en) | 1986-09-26 | 1986-09-26 | Sound pickup device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61229019A JPH071959B2 (en) | 1986-09-26 | 1986-09-26 | Sound pickup device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6382197A JPS6382197A (en) | 1988-04-12 |
| JPH071959B2 true JPH071959B2 (en) | 1995-01-11 |
Family
ID=16885476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61229019A Expired - Lifetime JPH071959B2 (en) | 1986-09-26 | 1986-09-26 | Sound pickup device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH071959B2 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2687712B2 (en) * | 1990-07-26 | 1997-12-08 | 三菱電機株式会社 | Integrated video camera |
| CA2069356C (en) * | 1991-07-17 | 1997-05-06 | Gary Wayne Elko | Adjustable filter for differential microphones |
| US5243660A (en) * | 1992-05-28 | 1993-09-07 | Zagorski Michael A | Directional microphone system |
| JP3893730B2 (en) * | 1998-04-15 | 2007-03-14 | 松下電器産業株式会社 | Sound playback device |
| US7697827B2 (en) | 2005-10-17 | 2010-04-13 | Konicek Jeffrey C | User-friendlier interfaces for a camera |
| JP5633144B2 (en) * | 2009-12-22 | 2014-12-03 | ヤマハ株式会社 | Sound signal processing device |
| JP5633145B2 (en) * | 2009-12-22 | 2014-12-03 | ヤマハ株式会社 | Sound signal processing device |
| JP5410351B2 (en) * | 2010-03-31 | 2014-02-05 | 綜合警備保障株式会社 | Security device and security method |
| JPWO2019012587A1 (en) | 2017-07-10 | 2020-08-13 | ヤマハ株式会社 | Gain adjusting device, remote conversation device, gain adjusting method, and gain adjusting program |
| WO2021068167A1 (en) | 2019-10-10 | 2021-04-15 | Shenzhen Voxtech Co., Ltd. | Audio device |
-
1986
- 1986-09-26 JP JP61229019A patent/JPH071959B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6382197A (en) | 1988-04-12 |
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