ATE13953T1 - Verfahren und vorrichtung fuer niederfrequente, aktive schalldaempfung. - Google Patents

Verfahren und vorrichtung fuer niederfrequente, aktive schalldaempfung.

Info

Publication number
ATE13953T1
ATE13953T1 AT82902368T AT82902368T ATE13953T1 AT E13953 T1 ATE13953 T1 AT E13953T1 AT 82902368 T AT82902368 T AT 82902368T AT 82902368 T AT82902368 T AT 82902368T AT E13953 T1 ATE13953 T1 AT E13953T1
Authority
AT
Austria
Prior art keywords
pct
volume
low
noise reduction
nulled
Prior art date
Application number
AT82902368T
Other languages
English (en)
Inventor
George Brian Barrie Chaplin
Andrew Jones
Owen Jones
Original Assignee
Sound Attenuators 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 Sound Attenuators Ltd filed Critical Sound Attenuators Ltd
Application granted granted Critical
Publication of ATE13953T1 publication Critical patent/ATE13953T1/de

Links

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
    • 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
    • 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
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17861—Methods, e.g. algorithms; Devices using additional means for damping sound, e.g. using sound absorbing panels
    • 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
    • G10K11/17879—General system configurations using both a reference signal and an error signal
    • G10K11/17881—General system configurations using both a reference signal and an error signal the reference signal being an acoustic signal, e.g. recorded with a microphone
    • 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
    • G10K2210/10—Applications
    • G10K2210/128—Vehicles
    • G10K2210/1282—Automobiles
    • G10K2210/12822—Exhaust pipes or mufflers
    • 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
    • G10K2210/3045—Multiple acoustic inputs, single acoustic output
    • 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
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3227—Resonators
    • G10K2210/32271—Active resonators
    • 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
    • G10K2210/3227—Resonators
    • G10K2210/32272—Helmholtz resonators

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Mechanical Engineering (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Exhaust Silencers (AREA)
  • Transmitters (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
  • Pipe Accessories (AREA)
  • Compressor (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
  • Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
AT82902368T 1981-08-11 1982-08-10 Verfahren und vorrichtung fuer niederfrequente, aktive schalldaempfung. ATE13953T1 (de)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB8124567 1981-08-11
PCT/GB1982/000250 WO1983000580A1 (en) 1981-08-11 1982-08-10 Method and apparatus for low frequency active attenuation
EP82902368A EP0085691B1 (de) 1981-08-11 1982-08-10 Verfahren und vorrichtung für niederfrequente, aktive schalldämpfung

Publications (1)

Publication Number Publication Date
ATE13953T1 true ATE13953T1 (de) 1985-07-15

Family

ID=10523873

Family Applications (1)

Application Number Title Priority Date Filing Date
AT82902368T ATE13953T1 (de) 1981-08-11 1982-08-10 Verfahren und vorrichtung fuer niederfrequente, aktive schalldaempfung.

Country Status (10)

Country Link
US (1) US4527282A (de)
EP (1) EP0085691B1 (de)
JP (1) JPS58501292A (de)
AT (1) ATE13953T1 (de)
AU (1) AU552258B2 (de)
DE (1) DE3264276D1 (de)
GB (1) GB2105948B (de)
NO (1) NO158392C (de)
WO (1) WO1983000580A1 (de)
ZA (1) ZA825676B (de)

Families Citing this family (80)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5257316A (en) * 1990-10-31 1993-10-26 Matsushita Electric Works, Ltd. Acoustic conductance and silencer utilizing same
US4562589A (en) * 1982-12-15 1985-12-31 Lord Corporation Active attenuation of noise in a closed structure
GB8405914D0 (en) * 1984-03-07 1984-04-11 Swinbanks M A Reducing noise by cancellation
US4677677A (en) * 1985-09-19 1987-06-30 Nelson Industries Inc. Active sound attenuation system with on-line adaptive feedback cancellation
US4665549A (en) * 1985-12-18 1987-05-12 Nelson Industries Inc. Hybrid active silencer
US4677676A (en) * 1986-02-11 1987-06-30 Nelson Industries, Inc. Active attenuation system with on-line modeling of speaker, error path and feedback pack
GB8603678D0 (en) * 1986-02-14 1986-03-19 Gen Electric Co Plc Active noise control
US4736431A (en) * 1986-10-23 1988-04-05 Nelson Industries, Inc. Active attenuation system with increased dynamic range
CA1299725C (en) * 1987-07-20 1992-04-28 Robert Christopher Twiney Noise reduction systems
US4750523A (en) * 1987-10-30 1988-06-14 Beloit Corporation Active attenuator and method
AU622158B2 (en) * 1988-02-19 1992-04-02 Noise Cancellation Technologies, Inc. Active sound attenuation system for engine exhaust systems and the like
US5097923A (en) * 1988-02-19 1992-03-24 Noise Cancellation Technologies, Inc. Active sound attenation system for engine exhaust systems and the like
KR0137271B1 (ko) * 1988-02-19 1998-04-25 원본미기재 기관 배기 시스템을 위한 능동음(音)감쇠 시스템
US5119427A (en) * 1988-03-14 1992-06-02 Hersh Alan S Extended frequency range Helmholtz resonators
US4947435A (en) * 1988-03-25 1990-08-07 Active Noise & Vibration Tech Method of transfer function generation and active noise cancellation in a vibrating system
GB2218301B (en) * 1988-04-29 1992-06-03 Gen Electric Co Plc Active noise control
DE3816921A1 (de) * 1988-05-18 1989-11-30 Bayerische Motoren Werke Ag Anordnung zur verminderung des geraeuschpegels im innenraum eines kraftfahrzeugs
JPH083395B2 (ja) * 1988-09-30 1996-01-17 株式会社東芝 冷却装置の消音装置
US5044464A (en) * 1990-01-23 1991-09-03 Nelson Industries, Inc. Active acoustic attenuation mixing chamber
US5125241A (en) * 1990-03-12 1992-06-30 Kabushiki Kaisha Toshiba Refrigerating apparatus having noise attenuation
EP0542749B1 (de) * 1990-04-09 1997-12-03 Noise Cancellation Technologies, Inc. Schalldämpfervorrichtung
US5272286A (en) * 1990-04-09 1993-12-21 Active Noise And Vibration Technologies, Inc. Single cavity automobile muffler
US5133017A (en) * 1990-04-09 1992-07-21 Active Noise And Vibration Technologies, Inc. Noise suppression system
US5457749A (en) * 1990-04-09 1995-10-10 Noise Cancellation Technologies, Inc. Electronic muffler
US5233137A (en) * 1990-04-25 1993-08-03 Ford Motor Company Protective anc loudspeaker membrane
US5319165A (en) * 1990-04-25 1994-06-07 Ford Motor Company Dual bandpass secondary source
JPH0684860B2 (ja) * 1990-05-01 1994-10-26 株式会社東芝 低騒音冷蔵庫
US5233540A (en) * 1990-08-30 1993-08-03 The Boeing Company Method and apparatus for actively reducing repetitive vibrations
US5245552A (en) * 1990-10-31 1993-09-14 The Boeing Company Method and apparatus for actively reducing multiple-source repetitive vibrations
US5255321A (en) * 1990-12-05 1993-10-19 Harman International Industries, Inc. Acoustic transducer for automotive noise cancellation
GB9116433D0 (en) * 1991-07-30 1991-09-11 Active Noise & Vibration Tech Noise reduction system
US5283834A (en) * 1991-08-26 1994-02-01 Nelson Industries, Inc. Acoustic system suppressing detection of higher order modes
US5347585A (en) * 1991-09-10 1994-09-13 Calsonic Corporation Sound attenuating system
US5822439A (en) * 1992-05-01 1998-10-13 Fujitsu Ten Limited Noise control device
JP2590885Y2 (ja) * 1992-07-29 1999-02-24 カルソニック株式会社 能動型消音器
US5732143A (en) * 1992-10-29 1998-03-24 Andrea Electronics Corp. Noise cancellation apparatus
US5748749A (en) * 1993-03-24 1998-05-05 Noise Cancellation Technologies, Inc. Active noise cancelling muffler
US5452361A (en) * 1993-06-22 1995-09-19 Noise Cancellation Technologies, Inc. Reduced VLF overload susceptibility active noise cancellation headset
US5502770A (en) * 1993-11-29 1996-03-26 Caterpillar Inc. Indirectly sensed signal processing in active periodic acoustic noise cancellation
JPH07162979A (ja) * 1993-12-10 1995-06-23 Fujitsu Ltd マイクロホン取付け構造
US5660255A (en) * 1994-04-04 1997-08-26 Applied Power, Inc. Stiff actuator active vibration isolation system
US5604813A (en) * 1994-05-02 1997-02-18 Noise Cancellation Technologies, Inc. Industrial headset
WO1995030393A1 (en) * 1994-05-10 1995-11-16 Noise Cancellation Technologies, Inc. Active noise cancelling muffler
US5418858A (en) * 1994-07-11 1995-05-23 Cooper Tire & Rubber Company Method and apparatus for intelligent active and semi-active vibration control
US5778081A (en) * 1996-03-04 1998-07-07 United Technologies Corp Active noise control using phased-array active resonators
US6353670B1 (en) 1996-07-02 2002-03-05 Donald R. Gasner Actively control sound transducer
US6078673A (en) * 1997-10-03 2000-06-20 Hood Technology Corporation Apparatus and method for active control of sound transmission through aircraft fuselage walls
US6665410B1 (en) 1998-05-12 2003-12-16 John Warren Parkins Adaptive feedback controller with open-loop transfer function reference suited for applications such as active noise control
DE19861018C2 (de) * 1998-12-15 2001-06-13 Fraunhofer Ges Forschung Gesteuerter akustischer Wellenleiter zur Schalldämpfung
US6363345B1 (en) 1999-02-18 2002-03-26 Andrea Electronics Corporation System, method and apparatus for cancelling noise
WO2001043490A2 (en) * 1999-12-09 2001-06-14 Frederick Johannes Bruwer Speech distribution system
US6594367B1 (en) 1999-10-25 2003-07-15 Andrea Electronics Corporation Super directional beamforming design and implementation
AU2001268459A1 (en) * 2000-06-14 2001-12-24 Sleep Solutions, Inc. Secure test and test result delivery system
US20030016833A1 (en) * 2001-07-19 2003-01-23 Siemens Vdo Automotive, Inc. Active noise cancellation system utilizing a signal delay to accommodate noise phase change
CA2420989C (en) * 2002-03-08 2006-12-05 Gennum Corporation Low-noise directional microphone system
US7477751B2 (en) * 2003-04-23 2009-01-13 Rh Lyon Corp Method and apparatus for sound transduction with minimal interference from background noise and minimal local acoustic radiation
FR2856107B1 (fr) * 2003-06-10 2005-09-09 Faurecia Sys Echappement Procede et dispositif d'attenuation du bruit produit en sortie d'une ligne d'echappement
DE102004040421A1 (de) * 2004-08-19 2006-03-09 J. Eberspächer GmbH & Co. KG Aktiver Abgasschalldämpfer
US8571227B2 (en) 2005-11-11 2013-10-29 Phitek Systems Limited Noise cancellation earphone
US20070125592A1 (en) * 2005-12-07 2007-06-07 Frank Michell Excitation of air directing valves and air handling surfaces in the cancellation of air handling system noise
US8302456B2 (en) 2006-02-23 2012-11-06 Asylum Research Corporation Active damping of high speed scanning probe microscope components
DE102006010558A1 (de) * 2006-03-06 2007-09-13 J. Eberspächer GmbH & Co. KG Aktiver Schalldämpfer für eine Abgasanlage
DE102006042224B3 (de) * 2006-09-06 2008-01-17 J. Eberspächer GmbH & Co. KG Aktiver Schalldämpfer für eine Abgasanlage
DE102007032600A1 (de) * 2007-07-11 2009-01-15 Deutsches Zentrum für Luft- und Raumfahrt e.V. Vorrichtung und Verfahren zur Verbesserung der Dämpfung von akustischen Wellen
NZ584418A (en) * 2007-10-02 2012-12-21 Phitek Systems Ltd Component for noise reducing earphone
DE102008015929A1 (de) * 2008-03-27 2009-10-01 J. Eberspächer GmbH & Co. KG Abgasanlage
EP2129114A3 (de) * 2008-05-29 2011-11-02 Phitek Systems Limited Medienerweiterungsmodul
US20110002474A1 (en) * 2009-01-29 2011-01-06 Graeme Colin Fuller Active Noise Reduction System Control
EP2226902A3 (de) * 2009-03-06 2013-03-13 Phitek Systems Limited Bordunterhaltungssystemverbinder
US20110075331A1 (en) * 2009-05-04 2011-03-31 Nigel Greig Media Player Holder
DE102009032553A1 (de) * 2009-07-10 2011-01-20 J. Eberspächer GmbH & Co. KG Abgasanlage und zugehörige Verbindungsanordnung für einen Aktuator
US20110188668A1 (en) * 2009-09-23 2011-08-04 Mark Donaldson Media delivery system
US9818394B2 (en) 2009-11-30 2017-11-14 Graeme Colin Fuller Realisation of controller transfer function for active noise cancellation
WO2011146429A1 (en) 2010-05-17 2011-11-24 Thales Avionics, Inc. Airline passenger seat modular user interface device
US9487295B2 (en) 2010-11-15 2016-11-08 William James Sim Vehicle media distribution system using optical transmitters
JP2014533444A (ja) 2011-06-01 2014-12-11 フィテック システムズ リミテッドＰｈｉｔｅｋ Ｓｙｓｔｅｍｓ Ｌｉｍｉｔｅｄ 能動騒音低減を組み込むインイヤー型装置
US8824695B2 (en) * 2011-10-03 2014-09-02 Bose Corporation Instability detection and avoidance in a feedback system
WO2013064602A1 (en) * 2011-11-04 2013-05-10 Empa Eidgenössische Materialprüfungs- Und Forschungsanstalt Adaptive helmholtz resonator
US9383388B2 (en) 2014-04-21 2016-07-05 Oxford Instruments Asylum Research, Inc Automated atomic force microscope and the operation thereof
CN112987508B (zh) * 2021-03-04 2022-09-30 长鑫存储技术有限公司 振动衰减结构及曝光装置

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1492963A (en) * 1974-02-22 1977-11-23 Lawson Tancred H Preventing or reducing transmission of sound
DE2507428A1 (de) * 1974-02-22 1975-08-28 Lawson Tancred Henry Verfahren und vorrichtung zur unterdrueckung oder abschwaechung der schallfortpflanzung
FR2329929A1 (fr) * 1975-10-31 1977-05-27 Anvar Dispositifs absorbeurs acoustiques actifs pour des conduits
GB2077988B (en) * 1979-11-21 1983-09-14 Chaplin George Brian Barrie Improved method and apparatus for cancelling vibration
EP0040462A1 (de) * 1980-05-16 1981-11-25 Bose Corporation Vorrichtung zur elektro-akustischen Dämpfung von Schallschwingungen im hörbaren Bereich

Also Published As

Publication number Publication date
US4527282A (en) 1985-07-02
EP0085691B1 (de) 1985-06-19
NO158392C (no) 1988-08-31
AU552258B2 (en) 1986-05-22
GB2105948B (en) 1985-04-11
GB2105948A (en) 1983-03-30
AU8764382A (en) 1983-02-22
NO831276L (no) 1983-04-11
JPS58501292A (ja) 1983-08-04
ZA825676B (en) 1983-06-29
EP0085691A1 (de) 1983-08-17
NO158392B (no) 1988-05-24
DE3264276D1 (en) 1985-08-01
WO1983000580A1 (en) 1983-02-17

Similar Documents

Publication Publication Date Title
AU552258B2 (en) Method and apparatus for low frequency active attenuation
ATE66553T1 (de) Verfahren zum uebertragen digitalisierter tonsignale.
GB1549893A (en) Method and device for reducing the noise of turbomachines
JPS54844A (en) Elastic surface wave filter
DE3650683D1 (de) Hybrider aktiver Schalldämpfer
DE69935974D1 (de) Verfahren und system zur behandlung von gerichtetem schall in einer akustisch-virtuellen umgegung
MY110378A (en) Arrangement for duplex transmission
GB2015083A (en) Silencer device for fluid-borne noise
GB1520143A (en) Elastic surface wave filter
JPS5219044A (en) Surface acoustic wave filter
ATE356469T1 (de) Verstärkungsregelung von audiosignalen in lärmender umgebung mit hilfe einer filterbank
CA1264812C (en) Spread spectrum communications system
DE69815836T2 (de) Interferenzunterdrückungssystem und verfahren mit doppelverarbeitung
JPS5529228A (en) Switching regulator for pcm device
EP0777337A3 (de) Spreizspektrum-Nachrichtenübertragungsgerät
JPS53132246A (en) Elastic surface wave filter
GB2057806A (en) Filter based on the use of surface acoustic waves
THORNTON Noise identification and reduction for a rotary vane compressor[Ph. D. Thesis]
IL60560A (en) Instrument for the treatment of an object by ultrasonic waves,and particularly for the removal of cataracts
JPS52137236A (en) High frequency attenuating element
HOUTGAST Lateral suppression and loudness reduction of a tone in noise(noting several masking experiments)
JPS6460025A (en) Transmitting/receiving device for communication
JPS5386939A (en) Electric wave noise prevention of engine
TUAN Research in gravity waves and airglow phenomena[Final Report, 1 Sep. 1973- 31 Aug. 1976]
JPS5234607A (en) Multifrequency signal receiving system

Legal Events

Date Code Title Description
UEP Publication of translation of european patent specification
EEIH Change in the person of patent owner
EELA Cancelled due to lapse of time