DE69125521D1 - Aktives akustisches Dämpfungssystem mit Gesamtmodellierung - Google Patents

Aktives akustisches Dämpfungssystem mit Gesamtmodellierung

Info

Publication number
DE69125521D1
DE69125521D1 DE69125521T DE69125521T DE69125521D1 DE 69125521 D1 DE69125521 D1 DE 69125521D1 DE 69125521 T DE69125521 T DE 69125521T DE 69125521 T DE69125521 T DE 69125521T DE 69125521 D1 DE69125521 D1 DE 69125521D1
Authority
DE
Germany
Prior art keywords
transducer
active acoustic
damping system
modeling
acoustic damping
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
DE69125521T
Other languages
English (en)
Other versions
DE69125521T2 (de
Inventor
Larry J Eriksson
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.)
Nelson Industries Inc
Original Assignee
Nelson Industries Inc
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 Nelson Industries Inc filed Critical Nelson Industries Inc
Publication of DE69125521D1 publication Critical patent/DE69125521D1/de
Application granted granted Critical
Publication of DE69125521T2 publication Critical patent/DE69125521T2/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • 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
    • G10K11/1781—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17813—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms
    • G10K11/17815—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms between the reference signals and the error signals, i.e. primary path
    • 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
    • G10K11/1781—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17813—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms
    • G10K11/17817—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms between the output signals and the error signals, i.e. secondary path
    • 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
    • G10K11/1781—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17813—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms
    • G10K11/17819—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 characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms between the output signals and the reference signals, e.g. to prevent howling
    • 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
    • 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
    • G10K11/17854—Methods, e.g. algorithms; Devices of the filter the filter being an adaptive 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
    • G10K11/1787—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
    • G10K2210/112—Ducts
    • 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
    • G10K2210/3017—Copy, i.e. whereby an estimated transfer function in one functional block is copied to another block
    • 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
    • G10K2210/3035—Models, e.g. of the acoustic 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
    • 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

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Prostheses (AREA)
  • Filters That Use Time-Delay Elements (AREA)
  • Vibration Prevention Devices (AREA)
  • Circuit For Audible Band Transducer (AREA)
DE69125521T 1990-05-03 1991-05-01 Aktives akustisches Dämpfungssystem mit Gesamtmodellierung Expired - Lifetime DE69125521T2 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US07/518,569 US4987598A (en) 1990-05-03 1990-05-03 Active acoustic attenuation system with overall modeling

Publications (2)

Publication Number Publication Date
DE69125521D1 true DE69125521D1 (de) 1997-05-15
DE69125521T2 DE69125521T2 (de) 1997-10-23

Family

ID=24064515

Family Applications (1)

Application Number Title Priority Date Filing Date
DE69125521T Expired - Lifetime DE69125521T2 (de) 1990-05-03 1991-05-01 Aktives akustisches Dämpfungssystem mit Gesamtmodellierung

Country Status (7)

Country Link
US (1) US4987598A (de)
EP (1) EP0455479B1 (de)
JP (1) JPH04226498A (de)
AT (1) ATE151553T1 (de)
AU (1) AU628778B2 (de)
CA (1) CA2041477C (de)
DE (1) DE69125521T2 (de)

Families Citing this family (52)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0834647B2 (ja) * 1990-06-11 1996-03-29 松下電器産業株式会社 消音装置
EP0465174B1 (de) * 1990-06-29 1996-10-23 Kabushiki Kaisha Toshiba Adaptive aktive Lärmunterdrückungseinrichtung
US5396561A (en) * 1990-11-14 1995-03-07 Nelson Industries, Inc. Active acoustic attenuation and spectral shaping system
US5216721A (en) * 1991-04-25 1993-06-01 Nelson Industries, Inc. Multi-channel active acoustic attenuation system
US5283834A (en) * 1991-08-26 1994-02-01 Nelson Industries, Inc. Acoustic system suppressing detection of higher order modes
US5370340A (en) * 1991-11-04 1994-12-06 General Electric Company Active control of aircraft engine noise using vibrational inputs
US5216722A (en) * 1991-11-15 1993-06-01 Nelson Industries, Inc. Multi-channel active attenuation system with error signal inputs
US5206911A (en) * 1992-02-11 1993-04-27 Nelson Industries, Inc. Correlated active attenuation system with error and correction signal input
FI94564C (fi) * 1992-02-14 1995-09-25 Nokia Deutschland Gmbh Aktiivinen melunvaimennusjärjestelmä
EP0578212B1 (de) * 1992-07-07 2000-06-14 Sharp Kabushiki Kaisha Aktive Regelungsvorrichtung mit einem adaptiven Digitalfilter
US5278913A (en) * 1992-07-28 1994-01-11 Nelson Industries, Inc. Active acoustic attenuation system with power limiting
US5315661A (en) * 1992-08-12 1994-05-24 Noise Cancellation Technologies, Inc. Active high transmission loss panel
US5390255A (en) * 1992-09-29 1995-02-14 Nelson Industries, Inc. Active acoustic attenuation system with error and model copy input
US5386689A (en) * 1992-10-13 1995-02-07 Noises Off, Inc. Active gas turbine (jet) engine noise suppression
GB2271908B (en) * 1992-10-21 1996-05-15 Lotus Car Adaptive control system
GB2271909B (en) * 1992-10-21 1996-05-22 Lotus Car Adaptive control system
US5386477A (en) * 1993-02-11 1995-01-31 Digisonix, Inc. Active acoustic control system matching model reference
WO1994027525A1 (en) * 1993-05-21 1994-12-08 Noise Cancellation Technologies, Inc. Active ear defender
US5327496A (en) * 1993-06-30 1994-07-05 Iowa State University Research Foundation, Inc. Communication device, apparatus, and method utilizing pseudonoise signal for acoustical echo cancellation
US5519637A (en) * 1993-08-20 1996-05-21 Mcdonnell Douglas Corporation Wavenumber-adaptive control of sound radiation from structures using a `virtual` microphone array method
US5420932A (en) * 1993-08-23 1995-05-30 Digisonix, Inc. Active acoustic attenuation system that decouples wave modes propagating in a waveguide
WO1995008155A1 (en) * 1993-09-17 1995-03-23 Noise Cancellation Technologies, Inc. Causal modeling of predictable impulse noise
US5502770A (en) * 1993-11-29 1996-03-26 Caterpillar Inc. Indirectly sensed signal processing in active periodic acoustic noise cancellation
US5586189A (en) * 1993-12-14 1996-12-17 Digisonix, Inc. Active adaptive control system with spectral leak
US5660255A (en) * 1994-04-04 1997-08-26 Applied Power, Inc. Stiff actuator active vibration isolation system
CA2148962C (en) * 1994-05-23 2000-03-28 Douglas G. Pedersen Coherence optimized active adaptive control system
US5557682A (en) * 1994-07-12 1996-09-17 Digisonix Multi-filter-set active adaptive control system
US5621803A (en) * 1994-09-02 1997-04-15 Digisonix, Inc. Active attenuation system with on-line modeling of feedback path
US5602929A (en) * 1995-01-30 1997-02-11 Digisonix, Inc. Fast adapting control system and method
JPH11509008A (ja) * 1995-07-05 1999-08-03 アルマックス インコーポレイテッド ダクトのハイオーダーモードのアクティブノイズ制御方法及び装置
AU6652496A (en) * 1995-08-11 1997-03-12 Centre De Recherche Industrielle Du Quebec Apparatus and method for adaptively attenuating noise or vibration
US5715320A (en) * 1995-08-21 1998-02-03 Digisonix, Inc. Active adaptive selective control system
US5710822A (en) * 1995-11-07 1998-01-20 Digisonix, Inc. Frequency selective active adaptive control system
JP3654980B2 (ja) * 1995-11-30 2005-06-02 富士通株式会社 能動騒音制御装置及び波形変換装置
JP3751359B2 (ja) * 1996-03-21 2006-03-01 本田技研工業株式会社 振動騒音制御装置
US5701350A (en) * 1996-06-03 1997-12-23 Digisonix, Inc. Active acoustic control in remote regions
US5832095A (en) * 1996-10-18 1998-11-03 Carrier Corporation Noise canceling system
US5968371A (en) * 1998-01-26 1999-10-19 Nelson Industries, Inc. Lubricant circulation diagnostic and modeling system
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
DE60004888T2 (de) * 1999-12-09 2004-07-15 Azoteq (Proprietary) Ltd. Sprachsverteilungssystem
WO2001067434A1 (en) * 2000-03-07 2001-09-13 Slab Dsp Limited Active noise reduction system
US6665411B2 (en) 2001-02-21 2003-12-16 Digisonix Llc DVE system with instability detection
WO2004009007A1 (en) * 2002-07-19 2004-01-29 The Penn State Research Foundation A linear independent method for noninvasive online secondary path modeling
US8302456B2 (en) * 2006-02-23 2012-11-06 Asylum Research Corporation Active damping of high speed scanning probe microscope components
US8068616B2 (en) * 2006-12-28 2011-11-29 Caterpillar Inc. Methods and systems for controlling noise cancellation
US7933420B2 (en) * 2006-12-28 2011-04-26 Caterpillar Inc. Methods and systems for determining the effectiveness of active noise cancellation
US8340318B2 (en) * 2006-12-28 2012-12-25 Caterpillar Inc. Methods and systems for measuring performance of a noise cancellation system
DE102007013719B4 (de) * 2007-03-19 2015-10-29 Sennheiser Electronic Gmbh & Co. Kg Hörer
EP2133866B1 (de) * 2008-06-13 2016-02-17 Harman Becker Automotive Systems GmbH Adaptives Geräuschdämpfungssystem
US8385559B2 (en) * 2009-12-30 2013-02-26 Robert Bosch Gmbh Adaptive digital noise canceller
DE102013216133A1 (de) * 2013-08-14 2015-02-19 Sennheiser Electronic Gmbh & Co. Kg Hörer oder Headset
US9383388B2 (en) 2014-04-21 2016-07-05 Oxford Instruments Asylum Research, Inc Automated atomic force microscope and the operation thereof

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4480333A (en) * 1981-04-15 1984-10-30 National Research Development Corporation Method and apparatus for active sound control
US4677677A (en) * 1985-09-19 1987-06-30 Nelson Industries Inc. Active sound attenuation system with on-line adaptive feedback cancellation
JPS62164400A (ja) * 1986-01-14 1987-07-21 Hitachi Plant Eng & Constr Co Ltd 電子消音システム
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
US4736431A (en) * 1986-10-23 1988-04-05 Nelson Industries, Inc. Active attenuation system with increased dynamic range
US4815139A (en) * 1988-03-16 1989-03-21 Nelson Industries, Inc. Active acoustic attenuation system for higher order mode non-uniform sound field in a duct
US4837834A (en) * 1988-05-04 1989-06-06 Nelson Industries, Inc. Active acoustic attenuation system with differential filtering

Also Published As

Publication number Publication date
JPH04226498A (ja) 1992-08-17
CA2041477C (en) 1996-09-03
US4987598A (en) 1991-01-22
EP0455479B1 (de) 1997-04-09
EP0455479A2 (de) 1991-11-06
CA2041477A1 (en) 1991-11-04
AU628778B2 (en) 1992-09-17
AU7632391A (en) 1991-11-07
EP0455479A3 (en) 1992-09-02
ATE151553T1 (de) 1997-04-15
DE69125521T2 (de) 1997-10-23

Similar Documents

Publication Publication Date Title
ATE151553T1 (de) Aktives akustisches dämpfungssystem mit gesamtmodellierung
ATE161648T1 (de) Aktives dämpfungssystem mit einer vorgegebenen akustischen ausgangswelle
CA2101228A1 (en) Active acoustic attenuation system with power limiting
DE69230192D1 (de) Mehrkanalige aktive Schalldämpfungsanordnung
DE69032637D1 (de) Kommunikationsanordnung mit activer Lärmunterdruckung
DE3774587D1 (de) Aktive daempfungsanordnung mit direkter modellierung von lautsprecher, fehlerweg und rueckkopplungsweg.
CA2082890A1 (en) Multi-channel active attenuation system with error signal inputs
SE7608834L (sv) Storningsupphevnde anordning
ATE204414T1 (de) Adaptiv vor- und rückwärts geregeltes system
FI863169A0 (fi) Fullstaendigt dubbelriktad hoegtalartelefon foer radio- och kabeltelefonsystem.
GB2222501A (en) Electronic noise attenuation system
DE69231190D1 (de) Aktives panel mit hoher übertragungsdämpfung
SE8403823L (sv) Minneskrets for transduktor
NO914326D0 (no) Akustisk transduser
DE69601732D1 (de) Verpackung
DE69111459D1 (de) Akustischer sender.
NO912532L (no) Fremgangsmaate og anordning for aa kontrollere en neddykketoppstilling av multi-kilder for utsendelse av akustiske pulser.
DE69105173D1 (de) Schwingungsdämpfungsanordnung eines Flugzeuges.
FR2673347B1 (fr) Transducteur electroacoustique a decouplage acoustique optimise.
JPS52112009A (en) Silencer of engine
ATE82425T1 (de) Schalldaemmeinrichtung.
STEPHENS A finite element approach to damped acoustic problems[Ph. D. Thesis]
DE69231712D1 (de) Adaptives loeschfiltermodul
FR2671221B1 (fr) Dispositif pour annulation de bruit acoustique.
FR2691828B1 (fr) Dispositif de réduction du bruit par court-circuit acoustique.

Legal Events

Date Code Title Description
8364 No opposition during term of opposition
8328 Change in the person/name/address of the agent

Representative=s name: BONGEN, RENAUD & PARTNER, 70173 STUTTGART