US2043416A - Process of silencing sound oscillations - Google Patents
Process of silencing sound oscillations Download PDFInfo
- Publication number
- US2043416A US2043416A US714582A US71458234A US2043416A US 2043416 A US2043416 A US 2043416A US 714582 A US714582 A US 714582A US 71458234 A US71458234 A US 71458234A US 2043416 A US2043416 A US 2043416A
- Authority
- US
- United States
- Prior art keywords
- sound
- oscillations
- microphone
- loudspeaker
- sound wave
- 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
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/02—Energy absorbers; Noise absorbers
- F16L55/033—Noise absorbers
- F16L55/0333—Noise absorbers by means of an active system
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/06—Silencing apparatus characterised by method of silencing by using interference effect
- F01N1/065—Silencing apparatus characterised by method of silencing by using interference effect by using an active noise source, e.g. speakers
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1785—Methods, e.g. algorithms; Devices
- G10K11/17853—Methods, e.g. algorithms; Devices of the filter
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1785—Methods, e.g. algorithms; Devices
- G10K11/17857—Geometric disposition, e.g. placement of microphones
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1787—General system configurations
- G10K11/17873—General system configurations using a reference signal without an error signal, e.g. pure feedforward
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/301—Computational
- G10K2210/3011—Single acoustic input
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/301—Computational
- G10K2210/3044—Phase shift, e.g. complex envelope processing
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/321—Physical
- G10K2210/3216—Cancellation means disposed in the vicinity of the source
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/321—Physical
- G10K2210/3217—Collocated sensor and cancelling actuator, e.g. "virtual earth" designs
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/50—Miscellaneous
- G10K2210/508—Reviews on ANC in general, e.g. literature
Definitions
- the present invention does away with these drawbacks and relates to a process of silencing sound oscillations especially of a disturbing nature, which can be employed independently of the source of oscillation.
- the sound oscillations, which are to be silenced are taken in by a receiver and reproduced by a reproducing apparatus in the form of sounds having an opposite phase.
- the means of carrying out said processes consist preferably of electrical apparatus and the reception is efiected by amicrophone, by which the acoustic oscillations are transformed into electric ones.
- the microphone is connected over an amplifier with a reproducing apparatus (loudspeaker).
- the phase opposition can be efiected by several means.
- the phase opposition can be efieeted in a very simple manner by adjusting the distance between the microphone and the producing apparatus.
- the microphone is preferably placed between the sound source and the reproducing apparatus causing the sound oscillations to meet first the microphone and then the reproducing apparatus. Consequently two difierent kinds of oscillations are present in the reproducing apparatus, the one representing the sound oscillation of the tune, moving with normal soundvelocity, the other representing a wave advanced with respect to the first wave by electrical means between the microphone and the reproducing apparatus and reproduced by the reproducing apparatus.
- the phase opposition can be efiected by suitably adjusting the distance between themicrophone and the reproducing apparatus.
- the microphone and loudspeaker are suitably placed close to each other in such a way that the oscillations coming from a certain point will meet the microphone a silencing of the noise is effected within the range of the reproducer.
- one side of the loudspeaker diaphragm is used for it, whereas the other side is silenced.
- Figure 1 illustrates diagrammatically means of silencing a single linear sound wave.
- Figure 2 illustrates diagrammatically a plurality of sound waves and means for silencing or damping the same.
- Figure 3 is a diagram illustrating the sound waves.
- Figure 4 illustrates diagrammatically means for silencing spatial sound waves.
- Figure 1 illustrates a simple device by means of which a single predetermined tone which comes from a predetermined direction is silenced or damped within a pipe T.
- This sound or tone is actually a sine-like sound wave and is to be silenced or damped by a sound Wave having an opposite phase.
- This sound of opposite phase is produced simply by adjusting the distance between the microphone M, which is built into the pipe T and the sound reproducing device or loudspeaker L.
- the microphone is situated between the source of the sounds and the loudspeaker. Therefore, the sound waves s arriving from the point A first strike the microphone andthen the loudspeaker.
- the sound wave received by the microphone is transmitted electrically with the assistance of the amplifier E to the loudspeaker. Naturally this electrically transmitted sound wave is advanced in relation to the sound wave s which moves with a normal velocity of sound.
- the extent of this advancement of the electrically transmitted sound wave can be conveniently adjusted by adjusting the distance between the microphone and the loudspeaker. It is easily possible to determine and regulate the distance between the microphone and the loudspeaker in such manner that the sound wave s which is electrically reproduced by the loudspeaker has an opposite phase from the original natural sound wave 8 Therefore, due to this creation'of a sound wave having an opposite phase, the two sound waves will silence each other or dampen each other.
- Figure 2 shows a sound source A which, for
- the sound waves which-do not have a sine-like form, 1. e., noises, may be represented by the irregular curve G G, which is shown in Figure 3.
- G G which is shown in Figure 3.
- the noise emerging from the point A reaches the microphone M situated at a distance a from the point A.
- the microphone M transmits this noise electrically to the loudspeaker in such manner that an opposite wave is produced, such as shown in Figure 3. This means that each time when a thickening of the air meets the microphone the loudspeaker answers by a corresponding thinning of the air and vice versa.
- phase opposition is produced within the space B, mainly in the direction of the arrow B.
- means receiving sound oscillations travelling in the air and means reproducing sound oscillations within the field of action of the first-mentioned sound oscillations and causing them to travel substantially-in the same direction as that of the first-mentioned sound oscillations, the second-mentioned sound oscillations having an opposite phase in relation to the first-mentioned sound oscillations, whereby the received sound oscillations are silenced within the.
- a process of silencing sound oscillations comprising receiving a sound wave travelling through the air, causing said sound wave to produce electricaloscillations, and transforming said electrical oscillations into a sound wave having an opposite phase to the received sound wave and travelling through the air substantially in the direction of the received sound wave, whereby the received sound wave is silenced within the range of the second-mentioned sound wave.
- a microphone for receiving a sound wave travelling through the air in substantially one direction, an amplifier electrically connected with said microphone, and means electrically connected with said amplifier for transforming electrical oscillations caused by said sound wave into another sound wave traveling through the air'substantially in the same direction as-the received sound wave, the distance between said microphone and said means being adjustable to cause a mutual elimination of the two sound waves within the field of action of the received sound wave.
- a microphone adapted to receive sound waves emitted by said source and situated at a certain distance from said source, and a loudspeaker electrically connected with said microphone and situated at the same distance from said source, said loudspeaker producing sound waves having an opposite phase to the received sound waves and travelling through the air substantially in the same direction as the received sound waves, whereby the receivedsound waves are eliminated within the field of action of the sound waves produced by the loudspeaker.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Description
Patented June 9, 1936 PROCESS OF SILENCING SOUND OSCILLA TIONS Paul Lueg, Kirchstrasse, Germany Application March 8, 1934, Serial No. 714,582 In Germany January 27, 1933' 4 Claims.
In the known processes of silencing sound oscillations the silencing is effected by subjecting these oscillations to a displacement of phases, but in these processes only the source of the oscillations is used to cause the displacement of phases, so that the superposition of phasestakes place in a purely mechanical manner.
The present invention does away with these drawbacks and relates to a process of silencing sound oscillations especially of a disturbing nature, which can be employed independently of the source of oscillation. According to the present invention the sound oscillations, which are to be silenced are taken in by a receiver and reproduced by a reproducing apparatus in the form of sounds having an opposite phase. The means of carrying out said processes consist preferably of electrical apparatus and the reception is efiected by amicrophone, by which the acoustic oscillations are transformed into electric ones. The microphone is connected over an amplifier with a reproducing apparatus (loudspeaker). The phase opposition can be efiected by several means. In case for instance of only one single tune moving in one well defined direction (in a pipe for instance) the phase opposition can be efieeted in a very simple manner by adjusting the distance between the microphone and the producing apparatus. In this case the microphone is preferably placed between the sound source and the reproducing apparatus causing the sound oscillations to meet first the microphone and then the reproducing apparatus. Consequently two difierent kinds of oscillations are present in the reproducing apparatus, the one representing the sound oscillation of the tune, moving with normal soundvelocity, the other representing a wave advanced with respect to the first wave by electrical means between the microphone and the reproducing apparatus and reproduced by the reproducing apparatus. The phase opposition can be efiected by suitably adjusting the distance between themicrophone and the reproducing apparatus.
In order to silence acoustic vibrations of any shape within a certain range, the microphone and loudspeaker are suitably placed close to each other in such a way that the oscillations coming from a certain point will meet the microphone a silencing of the noise is effected within the range of the reproducer. Preferably one side of the loudspeaker diaphragm is used for it, whereas the other side is silenced.
It is to be understood of course that in the 5 same way several receiving and reproducing apparatus can be used working either in a single way or in connection with each other.
Sometimes it will be necessary not to silence all the noise oscillations but only a part of them. This will be the case when for instance disagreeable secondary (stray) noises (see further below) for instance in theaters, concert halls, etc. have to be avoided. In the same way is this the case in ofiices in which the disagreeable noise of the type writing machines has to be silenced. This can be efiected in a very simple way in accordance with the invention by taking in well defined frequencies of the sound oscillations, by displacing the phases and reproducing same thereupon.
In the specification only the outstanding features of the process are stated and the means of the process may be modified by a more refined working out of the problem. The electric reception and the transforming of the acoustic oscillations have the advantage of an extraordinarily exact reproduction, so that a much more exact and more sudden silencing of the oscillations can be obtained than by the mechanical process. The process on the whole'can be employed in solid as well as in liquid and in gaseous sound carriers.
The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing showing by way of example preferred embodiments of the inventive idea.
In the drawing:--
Figure 1 illustrates diagrammatically means of silencing a single linear sound wave.
Figure 2 illustrates diagrammatically a plurality of sound waves and means for silencing or damping the same.
Figure 3 is a diagram illustrating the sound waves.
Figure 4 illustrates diagrammatically means for silencing spatial sound waves.
Figure 1 illustrates a simple device by means of which a single predetermined tone which comes from a predetermined direction is silenced or damped within a pipe T. This sound or tone is actually a sine-like sound wave and is to be silenced or damped by a sound Wave having an opposite phase. This sound of opposite phase is produced simply by adjusting the distance between the microphone M, which is built into the pipe T and the sound reproducing device or loudspeaker L. The microphone is situated between the source of the sounds and the loudspeaker. Therefore, the sound waves s arriving from the point A first strike the microphone andthen the loudspeaker. The sound wave received by the microphone is transmitted electrically with the assistance of the amplifier E to the loudspeaker. Naturally this electrically transmitted sound wave is advanced in relation to the sound wave s which moves with a normal velocity of sound.
The extent of this advancement of the electrically transmitted sound wave can be conveniently adjusted by adjusting the distance between the microphone and the loudspeaker. It is easily possible to determine and regulate the distance between the microphone and the loudspeaker in such manner that the sound wave s which is electrically reproduced by the loudspeaker has an opposite phase from the original natural sound wave 8 Therefore, due to this creation'of a sound wave having an opposite phase, the two sound waves will silence each other or dampen each other.
Figure 2 shows a sound source A which, for
instance, is situated in open space, so that it emits sound waves traveling in all directions. In that case the microphone M and the loudspeaker L are both placed at the same distance from the source A and are electrically interconnected by means of an amplifier V. 7, Sound waves (11 and an produced by the source A strike the microphone M and the loudspeaker L, respectively. The sound wave in striking the microphone M is reproduced by the loudspeaker L in an opposite phase. This changing of the phase may be accomplished by several well known methods, for instance, by changing the poles of the loudspeaker L, or by providing a transformer (not shown) between the loudspeaker L and the microphone M. The sound waves produced by the sound source A are silenced around the loud.- speaker L by sound waves having an opposite phase produced by the loudspeaker L.
The sound waves which-do not have a sine-like form, 1. e., noises, may be represented by the irregular curve G G, which is shown in Figure 3. Naturally an exact phase opposition cannot be produced by shifting a sound wave of this type by 180, since the two halves of the curve are entirely different one from the other. In that case the phase opposition is produced by the following means. In my present invention, I employ the principle that an ordinary oscillating membrane of a loudspeaker provided with fiat surfaces oi. the type employed in the usual surface loudspeaker, creates thickenings and thinnings of the air when a sound is reproduced. In the example illustrated in Figure 4, the noise emerging from the point A reaches the microphone M situated at a distance a from the point A. The microphone M transmits this noise electrically to the loudspeaker in such manner that an opposite wave is produced, such as shown in Figure 3. This means that each time when a thickening of the air meets the microphone the loudspeaker answers by a corresponding thinning of the air and vice versa.
Due to this arrangement, phase opposition is produced within the space B, mainly in the direction of the arrow B.
What I claim is:
1. In combination, means receiving sound oscillations travelling in the air and means reproducing sound oscillations within the field of action of the first-mentioned sound oscillations and causing them to travel substantially-in the same direction as that of the first-mentioned sound oscillations, the second-mentioned sound oscillations having an opposite phase in relation to the first-mentioned sound oscillations, whereby the received sound oscillations are silenced within the.
range of the reproduced sound oscillations.
- 2. A process of silencing sound oscillations comprising receiving a sound wave travelling through the air, causing said sound wave to produce electricaloscillations, and transforming said electrical oscillations into a sound wave having an opposite phase to the received sound wave and travelling through the air substantially in the direction of the received sound wave, whereby the received sound wave is silenced within the range of the second-mentioned sound wave. 1
3. In combination, a microphone for receiving a sound wave travelling through the air in substantially one direction, an amplifier electrically connected with said microphone, and means electrically connected with said amplifier for transforming electrical oscillations caused by said sound wave into another sound wave traveling through the air'substantially in the same direction as-the received sound wave, the distance between said microphone and said means being adjustable to cause a mutual elimination of the two sound waves within the field of action of the received sound wave.
4. In combination with a source of sound waves travelling through the air; a microphone adapted to receive sound waves emitted by said source and situated at a certain distance from said source, and a loudspeaker electrically connected with said microphone and situated at the same distance from said source, said loudspeaker producing sound waves having an opposite phase to the received sound waves and travelling through the air substantially in the same direction as the received sound waves, whereby the receivedsound waves are eliminated within the field of action of the sound waves produced by the loudspeaker.
PAUL LUEG.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2043416X | 1933-01-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2043416A true US2043416A (en) | 1936-06-09 |
Family
ID=7982314
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US714582A Expired - Lifetime US2043416A (en) | 1933-01-27 | 1934-03-08 | Process of silencing sound oscillations |
Country Status (1)
Country | Link |
---|---|
US (1) | US2043416A (en) |
Cited By (69)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2431862A (en) * | 1946-03-26 | 1947-12-02 | Sperry Prod Inc | Means for supersonic inspection |
US2516776A (en) * | 1946-08-07 | 1950-07-25 | Bell Telephone Labor Inc | Electroacoustic system and means |
US2611035A (en) * | 1950-01-31 | 1952-09-16 | Rca Corp | Noise-canceling microphone |
US2694868A (en) * | 1943-08-03 | 1954-11-23 | Edwin M Mcmillan | Echo repeater |
US2776020A (en) * | 1955-02-09 | 1957-01-01 | Gen Electric | Noise reducing system for transformers |
US2783008A (en) * | 1951-07-28 | 1957-02-26 | Jr Albert G Bodine | Acoustical boundary layer control for aerodynamic bodies |
US2966549A (en) * | 1954-04-02 | 1960-12-27 | Lawrence J Fogel | Apparatus for improving intelligence under high ambient noise levels |
US2972018A (en) * | 1953-11-30 | 1961-02-14 | Rca Corp | Noise reduction system |
US2983790A (en) * | 1953-04-30 | 1961-05-09 | Rca Corp | Electronic sound absorber |
US3044570A (en) * | 1957-04-08 | 1962-07-17 | Watts Ltd Cecil E | Loudspeakers |
US3071752A (en) * | 1958-01-02 | 1963-01-01 | Strasberg Murray | Interference reduction apparatus |
US3229429A (en) * | 1960-04-27 | 1966-01-18 | Conrad Ivan Willard | Secure conference systems |
US3308425A (en) * | 1965-09-03 | 1967-03-07 | Vector Cable Company | Depth sensitive transducer |
US3685610A (en) * | 1970-02-26 | 1972-08-22 | Messerschmitt Boelkow Blohm | Noise reduction for propellers |
US3826870A (en) * | 1970-03-20 | 1974-07-30 | Quest Electronics Corp | Noise cancellation |
US3936606A (en) * | 1971-12-07 | 1976-02-03 | Wanke Ronald L | Acoustic abatement method and apparatus |
US4044203A (en) * | 1972-11-24 | 1977-08-23 | National Research Development Corporation | Active control of sound waves |
US4109108A (en) * | 1976-10-01 | 1978-08-22 | National Research Development Corporation | Attenuation of sound waves in ducts |
DE2712534A1 (en) * | 1977-03-22 | 1978-09-28 | Sound Attenuators Ltd | Active sound attenuation using secondary wave - has stored programme used to obtain signal representing secondary wave |
EP0040462A1 (en) * | 1980-05-16 | 1981-11-25 | Bose Corporation | Electroacoustical audible noise reducing apparatus |
US4473906A (en) * | 1980-12-05 | 1984-09-25 | Lord Corporation | Active acoustic attenuator |
US4805733A (en) * | 1987-07-07 | 1989-02-21 | Nippondenso Co., Ltd. | Active silencer |
US4989252A (en) * | 1988-09-30 | 1991-01-29 | Kabushiki Kaisha Toshiba | Silencer |
US5040156A (en) * | 1989-06-29 | 1991-08-13 | Battelle-Institut E.V. | Acoustic sensor device with noise suppression |
US5088575A (en) * | 1990-09-13 | 1992-02-18 | Nelson Industries, Inc. | Acoustic system with transducer and venturi |
DE4033269A1 (en) * | 1990-10-19 | 1992-04-23 | Gillet Heinrich Gmbh | MUFFLER SYSTEM FOR MOTOR VEHICLES |
US5117642A (en) * | 1989-12-18 | 1992-06-02 | Kabushiki Kaisha Toshiba | Low noise refrigerator and noise control method thereof |
US5127235A (en) * | 1989-12-18 | 1992-07-07 | Kabushiki Kaisha Toshiba | Low noise refrigerator and noise control method thereof |
DE4130559A1 (en) * | 1991-09-10 | 1993-03-25 | Calsonic Corp | Silencing system with expansion chamber formed in main pipe - incorporates combination of active and passive reflecting surfaces in pipes of different dia. |
US5255321A (en) * | 1990-12-05 | 1993-10-19 | Harman International Industries, Inc. | Acoustic transducer for automotive noise cancellation |
EP0611089A2 (en) * | 1993-02-11 | 1994-08-17 | DIGISONIX, Inc. | Active acoustic control system matching model reference |
US5355417A (en) * | 1992-10-21 | 1994-10-11 | The Center For Innovative Technology | Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors |
US5475761A (en) * | 1994-01-31 | 1995-12-12 | Noise Cancellation Technologies, Inc. | Adaptive feedforward and feedback control system |
US5488666A (en) * | 1993-10-01 | 1996-01-30 | Greenhalgh Technologies | System for suppressing sound from a flame |
US5662136A (en) * | 1995-09-11 | 1997-09-02 | Defense Research Technologies, Inc. | Acousto-fluidic driver for active control of turbofan engine noise |
DE19702390A1 (en) * | 1997-01-24 | 1998-07-30 | Audi Ag | Wind tunnel |
US6461144B1 (en) * | 1999-05-07 | 2002-10-08 | Alstom (Switzerland) Ltd | Method of controlling thermoacoustic vibrations in a combustion system, and combustion system |
US6622647B2 (en) | 2001-06-26 | 2003-09-23 | Depoy Martin L. | Active noise cancellation for a torpedo seeker head |
US6671224B1 (en) * | 2002-08-26 | 2003-12-30 | Schlumberger Technology Corporation | Active reduction of tool borne noise in a sonic logging tool |
US20040122614A1 (en) * | 1996-11-14 | 2004-06-24 | Lg Electronics, Inc. | Noise controller for controlling noise and method of removing noise |
US20040125922A1 (en) * | 2002-09-12 | 2004-07-01 | Specht Jeffrey L. | Communications device with sound masking system |
US20050189165A1 (en) * | 2004-02-12 | 2005-09-01 | Mathur Gopal P. | Method and apparatus for reducing acoustic noise |
US20060158814A1 (en) * | 2003-03-05 | 2006-07-20 | Masaru Wasaki | Noise supression circuit |
US7088828B1 (en) * | 2000-04-13 | 2006-08-08 | Cisco Technology, Inc. | Methods and apparatus for providing privacy for a user of an audio electronic device |
US20090180635A1 (en) * | 2008-01-10 | 2009-07-16 | Sun Microsystems, Inc. | Method and apparatus for attenuating fan noise through turbulence mitigation |
US20090284996A1 (en) * | 2008-05-15 | 2009-11-19 | Lockheed Martin Corporation | System and method of cancelling noise radiated from a switch-mode power converter |
US20100028134A1 (en) * | 2007-01-22 | 2010-02-04 | Alon Slapak | Quiet fan incorporating active noise control (anc) |
US20100064696A1 (en) * | 2006-11-03 | 2010-03-18 | Koninklijke Philips Electronics N.V. | Active control of an acoustic cooling system |
US20100202633A1 (en) * | 2008-01-29 | 2010-08-12 | Korea Advanced Institute Of Science And Technology | Sound system, sound reproducing apparatus, sound reproducing method, monitor with speakers, mobile phone with speakers |
US20100284544A1 (en) * | 2008-01-29 | 2010-11-11 | Korea Advanced Institute Of Science And Technology | Sound system, sound reproducing apparatus, sound reproducing method, monitor with speakers, mobile phone with speakers |
WO2013076137A1 (en) | 2011-11-25 | 2013-05-30 | Renault S.A.S. | Method and device for controlling an active noise reduction system |
EP2645362A1 (en) | 2012-03-26 | 2013-10-02 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Apparatus and method for improving the perceived quality of sound reproduction by combining active noise cancellation and perceptual noise compensation |
US20140276276A1 (en) * | 2011-10-25 | 2014-09-18 | Ryo Kurosawa | Therapeutic apparatus and therapeutic method |
CN104064176A (en) * | 2014-07-14 | 2014-09-24 | 曾斌 | Indoor noise elimination device |
US9230534B2 (en) | 2010-12-29 | 2016-01-05 | Zhongyi Xu | Suppression device for outdoor noise in indoor space |
US9253556B1 (en) | 2013-08-29 | 2016-02-02 | ConcealFab Corporation | Dissipative system for increasing audio entropy thereby diminishing auditory perception |
US9431001B2 (en) | 2011-05-11 | 2016-08-30 | Silentium Ltd. | Device, system and method of noise control |
WO2017089624A1 (en) | 2015-11-29 | 2017-06-01 | Norwegian Sensors As | Optical pressure sensor |
US20170198723A1 (en) * | 2016-01-11 | 2017-07-13 | Rolls-Royce North American Technologies Inc. | System and method of alleviating blade flutter |
US9786262B2 (en) | 2015-06-24 | 2017-10-10 | Edward Villaume | Programmable noise reducing, deadening, and cancelation devices, systems and methods |
US9792892B2 (en) | 2014-07-15 | 2017-10-17 | Amphenol Phitek Limited | Noise cancellation system |
EP3242292A1 (en) | 2016-05-04 | 2017-11-08 | Sontech International AB | A sound damping device |
US9928824B2 (en) | 2011-05-11 | 2018-03-27 | Silentium Ltd. | Apparatus, system and method of controlling noise within a noise-controlled volume |
US10045525B2 (en) | 2010-11-09 | 2018-08-14 | Technology International Incorporated | Active non-lethal avian denial infrasound systems and methods of avian denial |
DE102005037034B4 (en) | 2004-08-09 | 2018-10-04 | Brigham Young University | Method and system for controlling the energy density using a two-dimensional energy density sensor |
US10465539B2 (en) * | 2017-08-04 | 2019-11-05 | Pratt & Whitney Canada Corp. | Rotor casing |
CN111947926A (en) * | 2020-07-10 | 2020-11-17 | 西安工程大学 | Intelligent sliding bearing self-adaptive active noise reduction device and noise reduction method |
CN112901887A (en) * | 2021-01-14 | 2021-06-04 | 哈尔滨工程大学 | Pipeline low-frequency noise control device based on electroacoustic coupling |
US11401866B2 (en) * | 2018-03-08 | 2022-08-02 | Safran Nacelles | Active device for attenuating acoustic emissions for a turbojet engine including controlled turbines |
-
1934
- 1934-03-08 US US714582A patent/US2043416A/en not_active Expired - Lifetime
Cited By (85)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2694868A (en) * | 1943-08-03 | 1954-11-23 | Edwin M Mcmillan | Echo repeater |
US2431862A (en) * | 1946-03-26 | 1947-12-02 | Sperry Prod Inc | Means for supersonic inspection |
US2516776A (en) * | 1946-08-07 | 1950-07-25 | Bell Telephone Labor Inc | Electroacoustic system and means |
US2611035A (en) * | 1950-01-31 | 1952-09-16 | Rca Corp | Noise-canceling microphone |
US2783008A (en) * | 1951-07-28 | 1957-02-26 | Jr Albert G Bodine | Acoustical boundary layer control for aerodynamic bodies |
US2983790A (en) * | 1953-04-30 | 1961-05-09 | Rca Corp | Electronic sound absorber |
US2972018A (en) * | 1953-11-30 | 1961-02-14 | Rca Corp | Noise reduction system |
US2966549A (en) * | 1954-04-02 | 1960-12-27 | Lawrence J Fogel | Apparatus for improving intelligence under high ambient noise levels |
US2776020A (en) * | 1955-02-09 | 1957-01-01 | Gen Electric | Noise reducing system for transformers |
US3044570A (en) * | 1957-04-08 | 1962-07-17 | Watts Ltd Cecil E | Loudspeakers |
US3071752A (en) * | 1958-01-02 | 1963-01-01 | Strasberg Murray | Interference reduction apparatus |
US3229429A (en) * | 1960-04-27 | 1966-01-18 | Conrad Ivan Willard | Secure conference systems |
US3308425A (en) * | 1965-09-03 | 1967-03-07 | Vector Cable Company | Depth sensitive transducer |
US3685610A (en) * | 1970-02-26 | 1972-08-22 | Messerschmitt Boelkow Blohm | Noise reduction for propellers |
US3826870A (en) * | 1970-03-20 | 1974-07-30 | Quest Electronics Corp | Noise cancellation |
US3936606A (en) * | 1971-12-07 | 1976-02-03 | Wanke Ronald L | Acoustic abatement method and apparatus |
US4044203A (en) * | 1972-11-24 | 1977-08-23 | National Research Development Corporation | Active control of sound waves |
US4109108A (en) * | 1976-10-01 | 1978-08-22 | National Research Development Corporation | Attenuation of sound waves in ducts |
DE2712534A1 (en) * | 1977-03-22 | 1978-09-28 | Sound Attenuators Ltd | Active sound attenuation using secondary wave - has stored programme used to obtain signal representing secondary wave |
EP0040462A1 (en) * | 1980-05-16 | 1981-11-25 | Bose Corporation | Electroacoustical audible noise reducing apparatus |
US4473906A (en) * | 1980-12-05 | 1984-09-25 | Lord Corporation | Active acoustic attenuator |
US4805733A (en) * | 1987-07-07 | 1989-02-21 | Nippondenso Co., Ltd. | Active silencer |
US4989252A (en) * | 1988-09-30 | 1991-01-29 | Kabushiki Kaisha Toshiba | Silencer |
US5040156A (en) * | 1989-06-29 | 1991-08-13 | Battelle-Institut E.V. | Acoustic sensor device with noise suppression |
US5117642A (en) * | 1989-12-18 | 1992-06-02 | Kabushiki Kaisha Toshiba | Low noise refrigerator and noise control method thereof |
US5127235A (en) * | 1989-12-18 | 1992-07-07 | Kabushiki Kaisha Toshiba | Low noise refrigerator and noise control method thereof |
US5088575A (en) * | 1990-09-13 | 1992-02-18 | Nelson Industries, Inc. | Acoustic system with transducer and venturi |
DE4033269A1 (en) * | 1990-10-19 | 1992-04-23 | Gillet Heinrich Gmbh | MUFFLER SYSTEM FOR MOTOR VEHICLES |
US5255321A (en) * | 1990-12-05 | 1993-10-19 | Harman International Industries, Inc. | Acoustic transducer for automotive noise cancellation |
US5347585A (en) * | 1991-09-10 | 1994-09-13 | Calsonic Corporation | Sound attenuating system |
DE4130559A1 (en) * | 1991-09-10 | 1993-03-25 | Calsonic Corp | Silencing system with expansion chamber formed in main pipe - incorporates combination of active and passive reflecting surfaces in pipes of different dia. |
US5355417A (en) * | 1992-10-21 | 1994-10-11 | The Center For Innovative Technology | Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors |
EP0611089A2 (en) * | 1993-02-11 | 1994-08-17 | DIGISONIX, Inc. | Active acoustic control system matching model reference |
EP0611089A3 (en) * | 1993-02-11 | 1995-10-11 | Digisonix Inc | Active acoustic control system matching model reference. |
US5488666A (en) * | 1993-10-01 | 1996-01-30 | Greenhalgh Technologies | System for suppressing sound from a flame |
US5475761A (en) * | 1994-01-31 | 1995-12-12 | Noise Cancellation Technologies, Inc. | Adaptive feedforward and feedback control system |
US5662136A (en) * | 1995-09-11 | 1997-09-02 | Defense Research Technologies, Inc. | Acousto-fluidic driver for active control of turbofan engine noise |
US20040122614A1 (en) * | 1996-11-14 | 2004-06-24 | Lg Electronics, Inc. | Noise controller for controlling noise and method of removing noise |
DE19702390A1 (en) * | 1997-01-24 | 1998-07-30 | Audi Ag | Wind tunnel |
US6155111A (en) * | 1997-01-24 | 2000-12-05 | Audi Ag | Wind tunnel with air vibration phase cancellation |
US6461144B1 (en) * | 1999-05-07 | 2002-10-08 | Alstom (Switzerland) Ltd | Method of controlling thermoacoustic vibrations in a combustion system, and combustion system |
US7088828B1 (en) * | 2000-04-13 | 2006-08-08 | Cisco Technology, Inc. | Methods and apparatus for providing privacy for a user of an audio electronic device |
US6622647B2 (en) | 2001-06-26 | 2003-09-23 | Depoy Martin L. | Active noise cancellation for a torpedo seeker head |
US6671224B1 (en) * | 2002-08-26 | 2003-12-30 | Schlumberger Technology Corporation | Active reduction of tool borne noise in a sonic logging tool |
US20040125922A1 (en) * | 2002-09-12 | 2004-07-01 | Specht Jeffrey L. | Communications device with sound masking system |
US20060158814A1 (en) * | 2003-03-05 | 2006-07-20 | Masaru Wasaki | Noise supression circuit |
US7423520B2 (en) | 2003-03-05 | 2008-09-09 | Tdk Corporation | Noise suppressing circuit |
US7267196B2 (en) * | 2004-02-12 | 2007-09-11 | The Boeing Company | Method and apparatus for reducing acoustic noise |
US20050189165A1 (en) * | 2004-02-12 | 2005-09-01 | Mathur Gopal P. | Method and apparatus for reducing acoustic noise |
DE102005037034B4 (en) | 2004-08-09 | 2018-10-04 | Brigham Young University | Method and system for controlling the energy density using a two-dimensional energy density sensor |
US20100064696A1 (en) * | 2006-11-03 | 2010-03-18 | Koninklijke Philips Electronics N.V. | Active control of an acoustic cooling system |
US8855329B2 (en) | 2007-01-22 | 2014-10-07 | Silentium Ltd. | Quiet fan incorporating active noise control (ANC) |
US20100028134A1 (en) * | 2007-01-22 | 2010-02-04 | Alon Slapak | Quiet fan incorporating active noise control (anc) |
US8155332B2 (en) * | 2008-01-10 | 2012-04-10 | Oracle America, Inc. | Method and apparatus for attenuating fan noise through turbulence mitigation |
US20090180635A1 (en) * | 2008-01-10 | 2009-07-16 | Sun Microsystems, Inc. | Method and apparatus for attenuating fan noise through turbulence mitigation |
US20100202633A1 (en) * | 2008-01-29 | 2010-08-12 | Korea Advanced Institute Of Science And Technology | Sound system, sound reproducing apparatus, sound reproducing method, monitor with speakers, mobile phone with speakers |
US8369536B2 (en) | 2008-01-29 | 2013-02-05 | Korea Advanced Institute Of Science And Technology | Sound system, sound reproducing apparatus, sound reproducing method, monitor with speakers, mobile phone with speakers |
US20100284544A1 (en) * | 2008-01-29 | 2010-11-11 | Korea Advanced Institute Of Science And Technology | Sound system, sound reproducing apparatus, sound reproducing method, monitor with speakers, mobile phone with speakers |
US8077489B2 (en) | 2008-05-15 | 2011-12-13 | Lockheed Martin Corporation | System and method of cancelling noise radiated from a switch-mode power converter |
US20090284996A1 (en) * | 2008-05-15 | 2009-11-19 | Lockheed Martin Corporation | System and method of cancelling noise radiated from a switch-mode power converter |
US10045525B2 (en) | 2010-11-09 | 2018-08-14 | Technology International Incorporated | Active non-lethal avian denial infrasound systems and methods of avian denial |
US9230534B2 (en) | 2010-12-29 | 2016-01-05 | Zhongyi Xu | Suppression device for outdoor noise in indoor space |
US9431001B2 (en) | 2011-05-11 | 2016-08-30 | Silentium Ltd. | Device, system and method of noise control |
US9928824B2 (en) | 2011-05-11 | 2018-03-27 | Silentium Ltd. | Apparatus, system and method of controlling noise within a noise-controlled volume |
US10098802B2 (en) * | 2011-10-25 | 2018-10-16 | Ryo Kurosawa | Therapeutic apparatus and therapeutic method |
US20140276276A1 (en) * | 2011-10-25 | 2014-09-18 | Ryo Kurosawa | Therapeutic apparatus and therapeutic method |
WO2013076137A1 (en) | 2011-11-25 | 2013-05-30 | Renault S.A.S. | Method and device for controlling an active noise reduction system |
EP2645362A1 (en) | 2012-03-26 | 2013-10-02 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Apparatus and method for improving the perceived quality of sound reproduction by combining active noise cancellation and perceptual noise compensation |
US9253556B1 (en) | 2013-08-29 | 2016-02-02 | ConcealFab Corporation | Dissipative system for increasing audio entropy thereby diminishing auditory perception |
CN104064176A (en) * | 2014-07-14 | 2014-09-24 | 曾斌 | Indoor noise elimination device |
US9792892B2 (en) | 2014-07-15 | 2017-10-17 | Amphenol Phitek Limited | Noise cancellation system |
US9786262B2 (en) | 2015-06-24 | 2017-10-10 | Edward Villaume | Programmable noise reducing, deadening, and cancelation devices, systems and methods |
US10089973B2 (en) | 2015-06-24 | 2018-10-02 | Edward Villaume | Programmable noise reducing, deadening, and cancelation devices, systems, and methods |
WO2017089624A1 (en) | 2015-11-29 | 2017-06-01 | Norwegian Sensors As | Optical pressure sensor |
US10739220B2 (en) | 2015-11-29 | 2020-08-11 | Tunable InfraRed Technologies AS | Optical pressure sensor |
US10344711B2 (en) * | 2016-01-11 | 2019-07-09 | Rolls-Royce Corporation | System and method of alleviating blade flutter |
US20170198723A1 (en) * | 2016-01-11 | 2017-07-13 | Rolls-Royce North American Technologies Inc. | System and method of alleviating blade flutter |
WO2017191293A1 (en) | 2016-05-04 | 2017-11-09 | Sontech International Ab | A sound damping device |
EP3242292A1 (en) | 2016-05-04 | 2017-11-08 | Sontech International AB | A sound damping device |
US10465539B2 (en) * | 2017-08-04 | 2019-11-05 | Pratt & Whitney Canada Corp. | Rotor casing |
US11401866B2 (en) * | 2018-03-08 | 2022-08-02 | Safran Nacelles | Active device for attenuating acoustic emissions for a turbojet engine including controlled turbines |
CN111947926A (en) * | 2020-07-10 | 2020-11-17 | 西安工程大学 | Intelligent sliding bearing self-adaptive active noise reduction device and noise reduction method |
CN111947926B (en) * | 2020-07-10 | 2022-07-15 | 西安工程大学 | Intelligent sliding bearing self-adaptive active noise reduction device and noise reduction method |
CN112901887A (en) * | 2021-01-14 | 2021-06-04 | 哈尔滨工程大学 | Pipeline low-frequency noise control device based on electroacoustic coupling |
CN116085572A (en) * | 2021-01-14 | 2023-05-09 | 哈尔滨工程大学 | Electroacoustic coupling-based pipeline low-frequency noise control device |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2043416A (en) | Process of silencing sound oscillations | |
US3009991A (en) | Sound reproduction system | |
US1988250A (en) | Loud speaker and method of propagating sound | |
US1951669A (en) | Method and apparatus for producing sound | |
US9641923B2 (en) | Transducer system driven by a signal time delay | |
US2373560A (en) | Sound recording method and apparatus | |
US2437445A (en) | Sound reverberating device | |
US1678842A (en) | Microphone | |
US3136853A (en) | Music enhancing systems | |
US1757451A (en) | Means for suppressing secondary vibrations in diaphragms and the like | |
US3236958A (en) | Loudspeaker system | |
US1832832A (en) | Sound reproducing means | |
US1500331A (en) | Telephonic receiver | |
US1853286A (en) | Transmission and reproduction of sound | |
US1801521A (en) | Loud-speaker horn | |
US2967447A (en) | Apparatus for translating electrical musical tone signals into sound | |
US1855146A (en) | Method and apparatus for audition | |
US1631646A (en) | Sound-reproducing apparatus | |
US2923369A (en) | Acoustic reverberation arrangements | |
US1814554A (en) | Horn having resonating chambers at antinodal points | |
US1960449A (en) | Acoustic apparatus | |
US1735905A (en) | Microphone mounting | |
US1856749A (en) | Vibrating film for acoustic devices | |
CN112532901A (en) | Display device and terminal | |
US3708035A (en) | Diaphragm for loudspeakers |