US2338551A - Automatic volume control - Google Patents

Automatic volume control Download PDF

Info

Publication number
US2338551A
US2338551A US45023942A US2338551A US 2338551 A US2338551 A US 2338551A US 45023942 A US45023942 A US 45023942A US 2338551 A US2338551 A US 2338551A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
amplifier
output
gain
level
noise
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
Application number
Inventor
Stanko Edward
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.)
RCA Corp
Original Assignee
RCA Corp
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
Grant date

Links

Images

Classifications

    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03GCONTROL OF AMPLIFICATION
    • H03G3/00Gain control in amplifiers or frequency changers without distortion of the input signal
    • H03G3/20Automatic control
    • H03G3/22Automatic control in amplifiers having discharge tubes
    • H03G3/24Control dependent upon ambient noise level or sound level

Description

Jam 4, 1944. E. sTANKo AUTOMATIC VOLUME CONTROL Filed July 9, 1942 mbtbh.. @Qu H1 :inventor 0L Stanlio Cttorncg Patented Jan. 4, 1944 AUTOMATIC VOLUME CONTROL Edward Stanko, Haddon Heights, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application July 9, 1942, Serial No. 450,239

4 Claims.

This invention relates to an automatic volume control for controlling the output volume from a set of loudspeakers in accordance with`=the noise level in the vicinity of the speakers. The

output level of the apparatus is set to operate a certain degree above the surrounding noise level and as the noise level varies, the output volume varies similarly so that the output of the speakers is maintained sulciently audible above the other noises while if the noise level decreases, the output level of the speakers decreases so that the output will not be annoying and loud.

The invention is of use in theatres where the noise level changes in accordance with the size of the audience and in connection with announcement systems in manufacturing plants Where the noise level varies from time to time depending on the number and Variety of the machines in operation.

One object of the invention is to provide an improved volume control. Another object is to provide an automatic volume control for maintaining the sound output of a group of loudspeakers above the ambient noise level.

Another object of the invention is to provide a thermionic amplier with automatic volume level controls. l

Another object of the invention is to provide a thermionic amplifier in which the output level will be controlled in accordance with an extraneous sound source.

Other and incidental objects of the invention will be apparent to those skilled in the art from a reading of the following specification and an inspection of the accompanying drawing in which the single figure of drawing is a schematic block diagram of' an amplifier, loudspeaker and volume control arrangement in accordance with my invention.

In the drawing, the sound to be reproduced is fed into the double pole, triple throw switch I2 either from the microphone I0, a photoelectric or electromechanical sound reproducer II or from an appropriate transmission line indicated above the switch I2. Any one of these sources may be selected by the switch, as desired. 'I'he output from the switch I2 is fed in the usual voltage amplifier I3 through the variable gain amplifier Il to the usual power amplifier I5, which is provided with a gain control, and thence to the speakers I6. It will be understood that a larger or smaller number of speakers may be used and that a plurality of power amplifiers may be used depending on the power requirements of the speaker arrangement used. The variable gain amplifier I4 is preferably o1' the type in which the gain may be either increased or decreased on increase in applied voltage depending upon the polarity of the applied voltage which is determined by the reversing switch 21. A vportion of the input to the voltage amplifier I3 is fed to an amplier Il and thence to a rectier I8. The output from the rectifier I8 is fed through the switch 21 to the variable gain amplier I4, referred to above. A portion of the output from the rectifier I8 is fed through a stabilizing lter I9 to an appropriate Voltage control indicator tube 20 and another portion of the output is fed through an appropriate switch to a volume indication meter 2|.

Within the eld of sound output of the speakers IB and also within the eld of disturbance caused by noise sources which interfere with the sound reproduction from the speakers I6, there is located a microphone pickup 22. The output of the microphone 22 is passed through an appropriate phasing switch 23 to an amplier 24 which is provided with an appropriate volume control. The output from the amplifier 24 is fed to the rectifier I8 in such polarity relation that it opposes the output from the amplifier I'I and it is the difference of these two outputs which is applied to the variable gain amplifier I4 and to the volume indicators 20 and 2l.

The two inputs to the rectifier I8 are put in proper phase relation by the phasing switch 23 or its equivalent. Since most noises, both auditorium noises and factory machine noises are usually of low frequencies, a low pass filter 25 which may, for example, pass substantially all frequencies below 200 cycles, while greatly attenuating frequencies above that value, may be pro vided.

In order to insure that the microphone 22 and amplifier 24 will be predominantly controlled from the noise sources rather than from the auditorium speakers, a high pass lter 26 greatly attenuating the frequencies passed by the filter 25 may be inserted at an appropriate point in the audio frequency channel.

It will be apparent from the foregoing that in the normal use of this apparatus the noise level around the microphone 22 will determine the gain of the amplifier I4 and thereby determine the output of the speakers I6. The apparatus may, however, be used for other purposes. For example, if the amplifier 24 is turned oft or the phasing switch 23 is left open, then the only input .to the rectifier I8 will be from the amplifier Il.

If the switch 21 is then turned to the opposite polarity of input to the amplifier Il from that used for controlling the speakers in accordance with the noise level, the circuit will act as a. compressor and the output from the speakers I6 will be rendered at a more uniform level than the input through the switch I2, the high amplitudes being lowered and the low amplitudes 1 being raised.

The apparatus may also be used to measure the frequency characteristics of an auditorium. If the switch 21 is left open so that the output of the rectifier does not affect the output of the speakers and if a variable frequency constant output record is reproduced by the apparatus I I. then the microphone 22 will pick up the effective sound level in the auditorium and the indicator ZI will then indicate the' difference between the input to the speakers I6 and the auditorium sound level produced thereby. If the characteristics of the various amplifiers, speakers and the microphone are known, then the readings of the meter 2| may be used directly to determine the auditorium frequency response.

In the first applications of this apparatus, the amount by which the sound level produced by the speakers I6 exceeds the noise level is determined by the gain control on the amplifier i5 and with the setting of this gain control, the variation in the output is determined by the variable gain amplifier I4.

I claim as my invention:

1. In combination a Variable gain amplifier, loudspeakers operated by the output from said amplifier, noise pick-up means, and means operated by said noise pick-up means and varying the gain of said amplifier in accordance with the noise level.

2. In combination a loudspeaker, an amplifier supplying audio frequency current to -said loudspeaker, sound pick-up means in the acoustic field of said speaker for picking up noise, and means controlled by the output of said sound pick-up means and controlling the output of said amplifier.

3. In combination a source of audio frequency impulses, a variable gain amplifier fed from said source, a power amplifier actuated by the output from the variable gain amplifier and loudspeakers operated by the output from the power amplifier, a second amplifier operated by the audio frequency impulses and feeding a rectifier connected to the variable gain amplifier, and a miorophone within the acoustic field of the loudspeakers and feeding the rectifier through an amplifier connected in opposition to the second amplifier whereby the gain of the variable gain amplifier is determined by the difference in the input to said rectier.

4. In combination a source of audio frequency impulses, a variable gain amplifier fed from said source, a power amplifier actuated by the output from the variable gain amplifier and loudspeakers operated by the output from the power amplifier, a second amplifier operated by the audio frequency impulses and feeding a rectifier connected to the variable gain amplifier. a microphone within the acoustic field of the loudspeakers and feeding the rectifier through an amplifier connected in opposition to the second amplifier whereby the gain of the Variable gain amplifier is determined by the difference in the input to said rectifier, and a reversing switch between the rectifier and the variable gain amplier.

EDWARD STANKO.

US2338551A 1942-07-09 1942-07-09 Automatic volume control Expired - Lifetime US2338551A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US2338551A US2338551A (en) 1942-07-09 1942-07-09 Automatic volume control

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US2338551A US2338551A (en) 1942-07-09 1942-07-09 Automatic volume control

Publications (1)

Publication Number Publication Date
US2338551A true US2338551A (en) 1944-01-04

Family

ID=23787299

Family Applications (1)

Application Number Title Priority Date Filing Date
US2338551A Expired - Lifetime US2338551A (en) 1942-07-09 1942-07-09 Automatic volume control

Country Status (1)

Country Link
US (1) US2338551A (en)

Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2420933A (en) * 1944-08-05 1947-05-20 Wurlitzer Co Automatic volume control
US2457712A (en) * 1945-09-21 1948-12-28 Rca Corp Method and apparatus for noise control of reproduced sound
US2462532A (en) * 1947-06-13 1949-02-22 Stromberg Carlson Co Sound system which compensates for variable noise levels
US2466216A (en) * 1947-06-13 1949-04-05 Stromberg Carlson Co Sound control system
US2468205A (en) * 1946-12-31 1949-04-26 Rca Corp Volume controlled sound reinforcement system
US2486480A (en) * 1946-02-08 1949-11-01 Reconstruction Finance Corp Volume control
US2489008A (en) * 1946-02-12 1949-11-22 Budd Co Broadcast receiving circuit and apparatus
US2495426A (en) * 1946-11-26 1950-01-24 Schwartzberg Henry Sound control system
US2501327A (en) * 1946-12-06 1950-03-21 Rca Corp Noise operated automatic volume control
US2503391A (en) * 1949-01-06 1950-04-11 Bell Telephone Labor Inc Automatic volume control
US2517629A (en) * 1947-04-29 1950-08-08 Hartford Nat Bank & Trust Co Volume control for sound reproduction systems
US2556889A (en) * 1948-05-29 1951-06-12 Rca Corp Public address system
US2563648A (en) * 1948-05-25 1951-08-07 Jr John Hays Hammond Microphone system having automatic volume level sensitivity
US2564437A (en) * 1949-11-26 1951-08-14 Bell Telephone Labor Inc Automatic volume control
US2593204A (en) * 1946-02-18 1952-04-15 Schwartzberg Henry Sound control system
US2616971A (en) * 1949-03-05 1952-11-04 Bell Telephone Labor Inc Automatic volume control
US2657264A (en) * 1949-09-17 1953-10-27 Bell Telephone Labor Inc Automatic volume control
US2929878A (en) * 1956-09-26 1960-03-22 Federal Ind Ind Group Inc Control signal generator
US2966549A (en) * 1954-04-02 1960-12-27 Lawrence J Fogel Apparatus for improving intelligence under high ambient noise levels
US3409738A (en) * 1965-04-16 1968-11-05 Rimac Ltd Volume controlled audio program broadcasting
US3410958A (en) * 1965-03-25 1968-11-12 Executone Inf Sys Inc Noise controlled sound reproducing system
US3497622A (en) * 1966-10-21 1970-02-24 Zenith Radio Corp Automatic gain control
DE2321765A1 (en) * 1972-10-16 1974-05-02 Rion Co hearing aid
US4254303A (en) * 1978-08-26 1981-03-03 Viva Co., Ltd. Automatic volume adjusting apparatus
US4322579A (en) * 1979-02-26 1982-03-30 U.S. Philips Corporation Sound reproduction in a space with an independent sound source
US4395600A (en) * 1980-11-26 1983-07-26 Lundy Rene R Auditory subliminal message system and method
US4777529A (en) * 1987-07-21 1988-10-11 R. M. Schultz & Associates, Inc. Auditory subliminal programming system
US5046101A (en) * 1989-11-14 1991-09-03 Lovejoy Controls Corp. Audio dosage control system
US5077799A (en) * 1989-01-13 1991-12-31 Brian Cotton Automatic volume control circuit
US5243657A (en) * 1992-07-31 1993-09-07 Brian Cotton Automatic microphone sensitivity control circuit
US5794204A (en) * 1995-06-22 1998-08-11 Seiko Epson Corporation Interactive speech recognition combining speaker-independent and speaker-specific word recognition, and having a response-creation capability
US5983186A (en) * 1995-08-21 1999-11-09 Seiko Epson Corporation Voice-activated interactive speech recognition device and method
US6070139A (en) * 1995-08-21 2000-05-30 Seiko Epson Corporation Bifurcated speaker specific and non-speaker specific speech recognition method and apparatus
US20050053252A1 (en) * 2003-03-10 2005-03-10 Cohen Daniel E. Sound and vibration transmission pad and system
US20060036201A1 (en) * 2003-03-10 2006-02-16 Cohen Daniel E Sound and vibration transmission pad and system
US20080130909A1 (en) * 2005-09-05 2008-06-05 Pishon Anc Co., Ltd. Apparatus and Method for Removing Ambient Noise and Mobile Communication Terminal Equipped with Apparatus
US20120051579A1 (en) * 2003-03-10 2012-03-01 Cohen Daniel E Sound and Vibration Transmission Pad and System
US9870678B2 (en) 2015-08-04 2018-01-16 Vanderbilt University Dynamic alarm system for reducing alarm fatigue

Cited By (43)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2420933A (en) * 1944-08-05 1947-05-20 Wurlitzer Co Automatic volume control
US2457712A (en) * 1945-09-21 1948-12-28 Rca Corp Method and apparatus for noise control of reproduced sound
US2486480A (en) * 1946-02-08 1949-11-01 Reconstruction Finance Corp Volume control
US2489008A (en) * 1946-02-12 1949-11-22 Budd Co Broadcast receiving circuit and apparatus
US2593204A (en) * 1946-02-18 1952-04-15 Schwartzberg Henry Sound control system
US2495426A (en) * 1946-11-26 1950-01-24 Schwartzberg Henry Sound control system
US2501327A (en) * 1946-12-06 1950-03-21 Rca Corp Noise operated automatic volume control
US2468205A (en) * 1946-12-31 1949-04-26 Rca Corp Volume controlled sound reinforcement system
US2517629A (en) * 1947-04-29 1950-08-08 Hartford Nat Bank & Trust Co Volume control for sound reproduction systems
US2466216A (en) * 1947-06-13 1949-04-05 Stromberg Carlson Co Sound control system
US2462532A (en) * 1947-06-13 1949-02-22 Stromberg Carlson Co Sound system which compensates for variable noise levels
US2563648A (en) * 1948-05-25 1951-08-07 Jr John Hays Hammond Microphone system having automatic volume level sensitivity
US2556889A (en) * 1948-05-29 1951-06-12 Rca Corp Public address system
US2503391A (en) * 1949-01-06 1950-04-11 Bell Telephone Labor Inc Automatic volume control
US2616971A (en) * 1949-03-05 1952-11-04 Bell Telephone Labor Inc Automatic volume control
US2657264A (en) * 1949-09-17 1953-10-27 Bell Telephone Labor Inc Automatic volume control
US2564437A (en) * 1949-11-26 1951-08-14 Bell Telephone Labor Inc Automatic volume control
US2966549A (en) * 1954-04-02 1960-12-27 Lawrence J Fogel Apparatus for improving intelligence under high ambient noise levels
US2929878A (en) * 1956-09-26 1960-03-22 Federal Ind Ind Group Inc Control signal generator
US3410958A (en) * 1965-03-25 1968-11-12 Executone Inf Sys Inc Noise controlled sound reproducing system
US3409738A (en) * 1965-04-16 1968-11-05 Rimac Ltd Volume controlled audio program broadcasting
US3497622A (en) * 1966-10-21 1970-02-24 Zenith Radio Corp Automatic gain control
DE2321765C3 (en) * 1972-10-16 1988-07-07 Rion K.K., Kokubunji, Tokio/Tokyo, Jp
DE2321765A1 (en) * 1972-10-16 1974-05-02 Rion Co hearing aid
US4254303A (en) * 1978-08-26 1981-03-03 Viva Co., Ltd. Automatic volume adjusting apparatus
US4322579A (en) * 1979-02-26 1982-03-30 U.S. Philips Corporation Sound reproduction in a space with an independent sound source
US4395600A (en) * 1980-11-26 1983-07-26 Lundy Rene R Auditory subliminal message system and method
US4777529A (en) * 1987-07-21 1988-10-11 R. M. Schultz & Associates, Inc. Auditory subliminal programming system
US5077799A (en) * 1989-01-13 1991-12-31 Brian Cotton Automatic volume control circuit
US5046101A (en) * 1989-11-14 1991-09-03 Lovejoy Controls Corp. Audio dosage control system
US5243657A (en) * 1992-07-31 1993-09-07 Brian Cotton Automatic microphone sensitivity control circuit
US5794204A (en) * 1995-06-22 1998-08-11 Seiko Epson Corporation Interactive speech recognition combining speaker-independent and speaker-specific word recognition, and having a response-creation capability
US5983186A (en) * 1995-08-21 1999-11-09 Seiko Epson Corporation Voice-activated interactive speech recognition device and method
US6070139A (en) * 1995-08-21 2000-05-30 Seiko Epson Corporation Bifurcated speaker specific and non-speaker specific speech recognition method and apparatus
US7553288B2 (en) 2003-03-10 2009-06-30 Cohen Daniel E Sound and vibration transmission pad and system
US20060036201A1 (en) * 2003-03-10 2006-02-16 Cohen Daniel E Sound and vibration transmission pad and system
US8668045B2 (en) * 2003-03-10 2014-03-11 Daniel E. Cohen Sound and vibration transmission pad and system
US20050053252A1 (en) * 2003-03-10 2005-03-10 Cohen Daniel E. Sound and vibration transmission pad and system
US20090250982A1 (en) * 2003-03-10 2009-10-08 Cohen Daniel E Sound and Vibration Transmission Pad and System
US7918308B2 (en) 2003-03-10 2011-04-05 Cohen Daniel E Sound and vibration transmission pad and system
US20120051579A1 (en) * 2003-03-10 2012-03-01 Cohen Daniel E Sound and Vibration Transmission Pad and System
US20080130909A1 (en) * 2005-09-05 2008-06-05 Pishon Anc Co., Ltd. Apparatus and Method for Removing Ambient Noise and Mobile Communication Terminal Equipped with Apparatus
US9870678B2 (en) 2015-08-04 2018-01-16 Vanderbilt University Dynamic alarm system for reducing alarm fatigue

Similar Documents

Publication Publication Date Title
US3246081A (en) Extended stereophonic systems
US4182930A (en) Detection and monitoring device
US4984273A (en) Enhancing bass
US4703507A (en) Noise reduction system
US3678416A (en) Dynamic noise filter having means for varying cutoff point
US6370254B1 (en) Audio-visual reproduction
US5436556A (en) Signal detector and method for detecting signals having selected frequency characteristics
US3571514A (en) Hearing aid tone control
US4045748A (en) Audio control system
US6968063B2 (en) Dynamic volume adjustment in a slot machine
US4490585A (en) Hearing aid
US4276443A (en) Sound reproducing system utilizing motional feedback and velocity-frequency equalization
US4191852A (en) Stereophonic sense enhancing apparatus
US4610024A (en) Audio apparatus
US5130665A (en) Audio volume level control
US4322641A (en) Noise reduction system
US2714633A (en) Perspective sound systems
US2343115A (en) Radio receiver circuit
US3934084A (en) Variable gain amplifier controlled by ambient noise level
US3249696A (en) Simplified extended stereo
US20010031054A1 (en) Automatic life audio signal derivation system
US3560656A (en) Binaural phase differential system
US3539729A (en) Apparatus for reducing interference in the transmission of electric signals
US4757545A (en) Amplifier circuit for a condenser microphone system
US3009991A (en) Sound reproduction system