JPS596634A - Voice switch circuit - Google Patents

Voice switch circuit

Info

Publication number
JPS596634A
JPS596634A JP11407882A JP11407882A JPS596634A JP S596634 A JPS596634 A JP S596634A JP 11407882 A JP11407882 A JP 11407882A JP 11407882 A JP11407882 A JP 11407882A JP S596634 A JPS596634 A JP S596634A
Authority
JP
Japan
Prior art keywords
circuit
noise
signal
gain
switch 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.)
Pending
Application number
JP11407882A
Other languages
Japanese (ja)
Inventor
Hisashi Fujisaki
久司 藤崎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP11407882A priority Critical patent/JPS596634A/en
Publication of JPS596634A publication Critical patent/JPS596634A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
    • H04M9/10—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic with switching of direction of transmission by voice frequency

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

PURPOSE:To keep a noise level to be applied to a listener after switching a voice switch circuit constant in level and to prevent the listener from feeling of physical disorder,by providing said circuit with a noise level detecting circuit, a variable attenuation circuit, etc. CONSTITUTION:An input signal including a voice signal and a background noise is applied to an input amplifier circuit 1 and a noise level detecting circuit 5 in the voice switch circuit and the input signal amplified by the circuit 1 is applied to a variable gain circuit 2. A channel switching controlling signal (a) is inputted to the circuit 2, the detecting circuit 5 and alpha variable attenuation circuit 6 to control the switch circuit in accordance with the state of the gain of the circuit 2. When the gain of the circuit is high under talking state, a noise signal generated in a noise generating circuit 7 is attenuated by the circuit 6 so as to be equalized with the noise level detected by the circuit 5 and the attenuated noise signal is added to the output of the circuit 2 by an adder and outputted. When the gain of the circuit 2 is low, the noise level detected by the circuit 5 is equalized with the noise level from the circuit 7 by the circuit 6 to remove the feeling of physical disorder to be applied to a listener.

Description

【発明の詳細な説明】 声インタホン等において使用される音声スイッチ回路に
関し，特に通話路切替制御信号によシ，通話路の利得を
大なる通話状態と小なる待受状態とに切シ替えることが
できる可変利得回路を備えた音声スイッチ回路に関する
。上記通話路切替制御信号は，通話路へ入力される音声
信号レベルの検出比較回路，又は手動スイッチ等によ多
発生される。[Detailed Description of the Invention] This invention relates to a voice switch circuit used in a voice intercom, etc., and in particular, to switch the gain of a communication path between a high talk state and a low standby state according to a communication path switching control signal. This invention relates to an audio switch circuit equipped with a variable gain circuit capable of The communication path switching control signal is often generated by a detection and comparison circuit for the level of an audio signal input to the communication path, a manual switch, or the like.

従来，音声スイッチ回路においては，通話路の利得の変
化量が大きい場合には、たとえ音声スイッチの切シ替わ
りがスムーズに行なわれた場合でも、音声信号とともに
背景雑音信号のレベルも変化するために、音声スイッチ
回路の動作による通話路の利得変化を受聴者に感じさせ
、音声スイッチ回路の存在を受聴者に意識させ、違和感
を与えるという欠点から逃がれる事ができなかった。Conventionally, in voice switch circuits, when the amount of change in the gain of the communication path is large, even if the voice switch is switched smoothly, the level of the background noise signal changes along with the voice signal. However, it is impossible to escape from the disadvantage that the listener is made to feel the change in the gain of the communication path due to the operation of the voice switch circuit, which makes the listener aware of the existence of the voice switch circuit, and gives a sense of discomfort.

本発明の目的は、音声スイッチ回路の切り替え動作前後
において、受聴哲へ与える雑音レベルを同一に保つこと
により、上記欠点を解決し、音声スイッチ回路の動作及
び存在を意識させないようにした新規な音声スイッチ回
路を提供することにある。An object of the present invention is to solve the above-mentioned drawbacks by keeping the noise level given to the listening ear the same before and after the switching operation of the voice switch circuit, and to create a new voice that does not make the user conscious of the operation and existence of the voice switch circuit. The purpose of the present invention is to provide a switch circuit.

すなわち１本発明は１通話路の利得が大なる通話状態の
時は入力信号（音声信号および背景雑音信号）に応じた
可変利得回路の出力信号の谷を加算回路へ加え、音声ス
イッチ回路の出力信号とする。この時１通話路へ入力さ
れる雑音信号レベルを雑音レベル検出回路によシ検出す
る。次に音声スイッチ回路が通話路の利得が小なる待受
状態に切り替わった時には、前記可変利得回路の出力信
号と残音発生回路によシ発生させた雑音信号とを前記加
算回路へ入力し、加算合成した信号を音声スイッチ回路
の出力信号とする。但し、前記加算回路へ入力する雑音
信号のレベルは前記雑音レベル検出回路により検出され
た雑音信号レベルに基づき１通話状態において音声スイ
ッチ回路の出力信号として出力された雑音信号レベルと
同一の出力レベルとなるように制御する。このような構
成をとることにより、音声スイッチ回路の動作による通
話路の利得変化を受聴者に感じさせないことが可能とな
る。In other words, in the present invention, when the gain of one communication path is large, the valley of the output signal of the variable gain circuit according to the input signal (voice signal and background noise signal) is added to the adder circuit, and the output of the voice switch circuit is Signal. At this time, the level of the noise signal input to one communication path is detected by the noise level detection circuit. Next, when the voice switch circuit switches to a standby state in which the gain of the communication path is small, inputting the output signal of the variable gain circuit and the noise signal generated by the after-sound generation circuit to the addition circuit; The added and synthesized signal is used as the output signal of the audio switch circuit. However, the level of the noise signal input to the addition circuit is the same output level as the noise signal level output as the output signal of the voice switch circuit in one call state based on the noise signal level detected by the noise level detection circuit. control so that By adopting such a configuration, it is possible to prevent the listener from feeling a change in the gain of the communication path due to the operation of the audio switch circuit.

以下２図面を参照して説明する。This will be explained below with reference to two drawings.

第１図を参照すると、従来の音声スイッチ回路は、入力
増幅回路１と、可変利得回路２と、出力増幅回路３とを
備えている。可変利得回路２は。Referring to FIG. 1, the conventional audio switch circuit includes an input amplifier circuit 1, a variable gain circuit 2, and an output amplifier circuit 3. The variable gain circuit 2 is.

通話路切替制御信号（ａ）によ９９通話路の利得を大な
る通話状態と小なる待受状態とに切シ替えることができ
る。通話路切替制御信号（ａ）は２通話路へ入力される
音声信号レベルの検出比較回路、又は手動スイッチ等に
より発生される。この音声スイッチ回路の利得の時間的
変化は第３図（ａ）のよう°であり、この音声スイッチ
回路の入力信号（ｂ）が第３図（ｂ）の場合、この音声
スイッチ回路の出力信号（ｃ）は第３図（Ｃ）のように
なる。The gain of the 99 call path can be switched between a high call state and a low standby state using the call path switching control signal (a). The communication path switching control signal (a) is generated by a detection and comparison circuit for audio signal levels input to the two communication paths, a manual switch, or the like. The temporal change in gain of this voice switch circuit is as shown in FIG. 3(a), and when the input signal (b) of this voice switch circuit is as shown in FIG. 3(b), the output signal of this voice switch circuit is (c) becomes as shown in FIG. 3(C).

第２図を参照すると２本発明の一実施例に係る音声スイ
ッチ回路は、入力増幅回路１と、可変利ばホス（ａｏｔ
ｈ）雑音発生回路を用いた雑音発生回路７とを備えてい
る。入力増幅回路１及び可変利得回路２は第１図のもの
と同じ機能を有する。以下２本実施例の動作を第３図を
も参照して説明する。Referring to FIG. 2, an audio switch circuit according to an embodiment of the present invention includes an input amplifier circuit 1, an input amplifier circuit 1, and an input amplifier circuit 1;
h) a noise generation circuit 7 using a noise generation circuit. The input amplifier circuit 1 and the variable gain circuit 2 have the same functions as those in FIG. The operation of the two embodiments will be explained below with reference to FIG.

本実施例の音声スイッチ回路の利得の時間的な変化は第
３図（ａ）のようであり、第３図（ｂ）に示す入力信号
（音声信号および雑音信号）は、入力増幅回路１．可変
利得回路２．および加算回路４を通って第３図（ｄ）に
示す出力信号（ｄ）として出力される。The temporal change in gain of the audio switch circuit of this embodiment is as shown in FIG. 3(a), and the input signals (speech signal and noise signal) shown in FIG. 3(b) are input to the input amplifier circuit 1. Variable gain circuit 2. Then, it passes through the adder circuit 4 and is output as an output signal (d) shown in FIG. 3(d).

通話路切替制御信号（ａ）が可変利得回路２の利得が大
である通話状態に音声スイッチ回路を制御している時は
、雑音発生回路７により発生した雑音信号は、可変減衰
回路６により大きな減衰をうけ。When the speech path switching control signal (a) is controlling the voice switch circuit to a speech state in which the gain of the variable gain circuit 2 is large, the noise signal generated by the noise generation circuit 7 is reduced by the variable attenuation circuit 6. subject to attenuation.

加算回路４へは入力されないよう制御され、出力音声信
号の信号対雑音比を悪化させることはない。The signal is controlled not to be input to the adder circuit 4, so that the signal-to-noise ratio of the output audio signal is not deteriorated.

この時２通話路へ入力される雑音信号レベルは雑音レベ
ル検出回路５により検出される。At this time, the noise signal level input to the two communication paths is detected by the noise level detection circuit 5.

次に１通話路切替制御゛信号（ａ）が可変利得回路２の
利得が小である待受状態に音声スイッチ回路を制御する
時には、雑音発生回路７により発生した雑音信号は、雑
音レベル検出回路５により制御される可変減衰器６によ
９２通話状態において出力された雑音信号と同一の出力
レベルの雑音として出力されるように加算回路４へ入力
される。Next, when the first communication path switching control signal (a) controls the voice switch circuit to the standby state in which the gain of the variable gain circuit 2 is small, the noise signal generated by the noise generation circuit 7 is transmitted to the noise level detection circuit. The signal is inputted to the adder circuit 4 so as to be outputted as a noise having the same output level as the noise signal outputted in the 92 call state by the variable attenuator 6 controlled by the signal generator 5.

このような構成をとることによシ、音声スイッチ回路の
動作により通話路の利得が変化しても。With this configuration, even if the gain of the communication path changes due to the operation of the voice switch circuit.

出力雑音レベルが変化しないので、受聴者に音声スイッ
チ回路の存在を意識させない音声スイッチ回路を構成す
ることが可能となる。Since the output noise level does not change, it is possible to configure a voice switch circuit that does not make the listener aware of the existence of the voice switch circuit.

本発明は以上説明したように、音声スイッチ回路の動作
によシ通話路の利得が変化しても、出力雑音レベルが変
化しないように構成したので、音声スイッチ回路の動作
や存在を受聴者に意識させず、違和感を与えないという
効果がある。As explained above, the present invention is configured so that the output noise level does not change even if the gain of the channel changes due to the operation of the voice switch circuit. It has the effect of not making you conscious or making you feel uncomfortable.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は従来の音声スイッチ回路のブロック図。 第２図は本発明の一実施例に係る音声スイッチ回路のブ
ロック図、第３図（ａ）は第１図及び第２図の音声スイ
ッチ回路の利得の時間的な変化を示し。 第３図（ｂ）は第１図及び第２図の音声スイッチ回路の
入力信号を示し、第３図（ｃ）は第１図の音声スイッチ
回路の出力信号を示し、第３図（（至）は第２図の音声
スイッチ回路の出力信号を示した図である。 １・・・入力増幅回路、２・・・可変利得回路、３・・
・出力増幅回路、４・・・加算回路、５・・・雑音レベ
ル検出回路、６・・・可変減衰回路、７・・・雑音発生
回路。 （ｄ）FIG. 1 is a block diagram of a conventional audio switch circuit. FIG. 2 is a block diagram of an audio switch circuit according to an embodiment of the present invention, and FIG. 3(a) shows temporal changes in gain of the audio switch circuits of FIGS. 1 and 2. 3(b) shows the input signal of the audio switch circuit of FIGS. 1 and 2, FIG. 3(c) shows the output signal of the audio switch circuit of FIG. ) is a diagram showing the output signal of the audio switch circuit in Fig. 2. 1... Input amplifier circuit, 2... Variable gain circuit, 3...
- Output amplification circuit, 4... Addition circuit, 5... Noise level detection circuit, 6... Variable attenuation circuit, 7... Noise generation circuit. (d)

Claims (1)

【特許請求の範囲】 １、通話路切替制御信号によシ、音声信号が入力される
通話路の利得を大なる通話状態と小なる待受状態とに切
シ替えることができる可変利得回路を備えた音声スイッ
チ回路において、前記通話路へ入力される雑音信号レベ
ルを検出する雑音レベル検出回路と、雑音発生回路と、
前記可変利得回路の出力信号と前記雑音発生回路の出力
雑音信号とを加算合成する加算回路と、前記通話路切替
制御信号及び前記雑音レベル検出回路の出力信号によシ
、前記雑音発生回路からの前記加算回路への入力信号を
制御する雑音制御回路とを備え、該雑音制御回路は、前
記通話路の利得が大なる通話記通話路の利得が小なる待
受状態の時には、前記雑音レベル検出回路の出力信号を
基に、前記加算器の出力信号における雑音信号レベルが
、前記通話状態の時の前記加算器の出力信号における雑
音信号レベルと同一レベルとなるように、前記雑音発生
回路から前記加算回路へ入力される雑音信号レベルを制
御する回路であり、前記加算器の出力信号を音声スイッ
チ回路出力信号としたことを特徴とする音声スイッチ回
路。 ２　雑音発生回路がホス雑音発生回路である特許請求の
範囲第１項記載の音声スイッチ回路。[Claims] 1. A variable gain circuit that can switch the gain of a communication path into which a voice signal is input between a high call state and a low standby state according to a communication path switching control signal. A voice switch circuit comprising: a noise level detection circuit for detecting a noise signal level input to the communication path; a noise generation circuit;
an adder circuit for adding and synthesizing the output signal of the variable gain circuit and the output noise signal of the noise generation circuit; a noise control circuit that controls an input signal to the adder circuit, and the noise control circuit detects the noise level when in a standby state where the gain of the communication path is large and the gain of the communication path is small. Based on the output signal of the circuit, the noise generation circuit generates the noise signal so that the noise signal level of the output signal of the adder is the same as the noise signal level of the output signal of the adder during the call state. 1. An audio switch circuit, which is a circuit for controlling a noise signal level input to an adder circuit, and wherein an output signal of the adder is used as an output signal of the audio switch circuit. 2. The audio switch circuit according to claim 1, wherein the noise generating circuit is a Hoss noise generating circuit.
JP11407882A 1982-07-02 1982-07-02 Voice switch circuit Pending JPS596634A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11407882A JPS596634A (en) 1982-07-02 1982-07-02 Voice switch circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11407882A JPS596634A (en) 1982-07-02 1982-07-02 Voice switch circuit

Publications (1)

Publication Number Publication Date
JPS596634A true JPS596634A (en) 1984-01-13

Family

ID=14628499

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11407882A Pending JPS596634A (en) 1982-07-02 1982-07-02 Voice switch circuit

Country Status (1)

Country Link
JP (1) JPS596634A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03139925A (en) * 1989-10-25 1991-06-14 Nec Corp Center clipper circuit

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5096223A (en) * 1973-12-19 1975-07-31
JPS5130731A (en) * 1974-09-07 1976-03-16 Sankyo Kogaku Kogyo Kk 1 ganrefukameranofuaindaanaigoshosochi
JPS55130522A (en) * 1979-03-31 1980-10-09 Konishiroku Photo Ind Co Ltd Single-lens reflex camera provided with ttl type focus detector

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5096223A (en) * 1973-12-19 1975-07-31
JPS5130731A (en) * 1974-09-07 1976-03-16 Sankyo Kogaku Kogyo Kk 1 ganrefukameranofuaindaanaigoshosochi
JPS55130522A (en) * 1979-03-31 1980-10-09 Konishiroku Photo Ind Co Ltd Single-lens reflex camera provided with ttl type focus detector

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03139925A (en) * 1989-10-25 1991-06-14 Nec Corp Center clipper circuit

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