WO2004002383A1 - Noise cancellation system and headphone therefor - Google Patents

Noise cancellation system and headphone therefor Download PDF

Info

Publication number
WO2004002383A1
WO2004002383A1 PCT/NZ2003/000134 NZ0300134W WO2004002383A1 WO 2004002383 A1 WO2004002383 A1 WO 2004002383A1 NZ 0300134 W NZ0300134 W NZ 0300134W WO 2004002383 A1 WO2004002383 A1 WO 2004002383A1
Authority
WO
WIPO (PCT)
Prior art keywords
noise cancellation
filter
headphone
sound transducer
cancellation system
Prior art date
Application number
PCT/NZ2003/000134
Other languages
French (fr)
Inventor
Mark Donaldson
Graeme Colin Fuller
Original Assignee
Phitek Systems Limited
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 Phitek Systems Limited filed Critical Phitek Systems Limited
Priority to JP2004517418A priority Critical patent/JP2005531807A/en
Priority to DE10392880T priority patent/DE10392880T5/en
Priority to US10/520,036 priority patent/US7489785B2/en
Priority to AU2003238975A priority patent/AU2003238975A1/en
Priority to GB0428314A priority patent/GB2406013B/en
Publication of WO2004002383A1 publication Critical patent/WO2004002383A1/en

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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
    • H04R1/1083—Reduction of ambient noise
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R5/00—Stereophonic arrangements
    • H04R5/033—Headphones for stereophonic communication

Definitions

  • the invention relates to noise cancellation systems, and is directed particularly, but not solely, towards a headphone noise cancellation system.
  • Passenger vehicles particularly commercial aircraft, have seat installations which include appropriate connections, i.e. jacks for receiving connection plugs for headsets and headphones.
  • the user either provides their own, or is provided with, a headset which the user plugs into the jack provided on the relevant seat to listen to various audio channels.
  • headset and headphone are used interchangeably in this document since it is not relevant to the current invention whether a user microphone is fitted.
  • the seat installation includes active noise cancellation electronic circuitry.
  • the circuitry is operative to provide noise cancellation based on feedback from an appropriate sound transducer such as a microphone which is provided within the headset.
  • the invention consists in a noise cancellation system having: a headphone including asound transducer and a headphone speaker, noise cancellation circuitry provided remote from the headphone, supplying the headphone speaker, and being supplied from the sound transducer, a filter to normalise the output from the sound transducer of the headphone to the noise cancellation circuitry.
  • the filter is located at the output of the sound transducer to enable effective noise cancellation to be achieved in use.
  • the filter comprises a passive electronic filter.
  • the filter comprises a resistor/capacitor network.
  • the filter is a high pass filter in parallel with the sound transducer.
  • the sound transducer comprises an electret condenser microphone.
  • the invention consists in a headphone for a noise cancellation system, the headphone including, one or more headphone speakers for providing sound to a user. at least one sound transducer provided in the headset adjacent to the speaker, and the output of the sound transducer being provided as an electrical signal and being provided to a filter, and the output of the filter being available to noise cancellation circuitry to cancel noise from the signal being delivered to the speaker.
  • Figure 1 is a circuit schematic of a noise cancellation system according to the invention
  • Figure 2 is a schematic of an equivalent circuit for a headset microphone and filter according to the invention
  • Figure 3 is a schematic for one example of a practical implementation of the invention.
  • the invention provides a way of allowing noise cancellation circuitry which is typically provided remote from a headphone, to be able to provide effective noise cancellation for a number of different headphone designs.
  • This is achieved by providing the noise cancellation headphone sound transducer (typically a microphone such as an electret condenser microphone) with a passive filter so that the feedback signal provided by the microphone is appropriately conditioned for a "generic" active noise cancellation circuit or normalised.
  • the invention allows the noise cancellation circuitry to be designed to be operative over a certain phase range of input feedback signals from a headset. This in turn means that a filter placed on the headset feedback signal may be appropriately configured for each different sort of headset so as to be acceptable to the noise cancellation circuitry and enable collective noise cancellation to be achieved.
  • the filter comprises a simple passive filter.
  • resistor/capacitor filter is a resistor/capacitor filter as described further below.
  • simple resistor capacitor passive filter provides an appropriate transfer function that is suitable for active noise cancellation applications.
  • This simple passive filter may have the values of resistance or capacitance varied dependent upon the nature of the headphone, the headphone sound transducer etc.
  • the noise cancellation circuitry is shown generally referenced 6.
  • the noise cancellation circuitry may be provided in a portable electronic device such as a portable audio system including those sold under the trade mark WALKMAN.
  • the circuitry could alternatively be provided in a home stereo system, a television set or a variety of other devices which provide sound to a user.
  • the noise cancellation circuitry 6 will be provided in a passenger vehicle. Again, a number of different forms of passenger transport may be provided so the noise cancellation circuitry may be provided in a seat installation
  • the sound transducer for the headphone 4 is an electret condenser microphone 8, and the output of the microphone is provided to a passive filter network comprising resistor 10 and capacitor 12.
  • the output from the passive filter network is referenced 14 and 16, and these outputs are typically provided as pins on a plug which is acceptable to an appropriate jack or socket on the device that includes the noise cancellation circuitry.
  • the headset 4 also includes a speaker 18 which has input signal connections 20 and 22. Again, connections 20 and 22 are in use electrically connected to an appropriate plug pins (not shown) so that they can be supplied with an appropriate electrical signal from the output of the noise cancellation circuitry that is provided in the corresponding socket remote from the headphone.
  • inputs 24 and 26 the input to the noise cancellation circuitry from the microphone is represented by inputs 24 and 26.
  • Input 26 may be a reference such as ground
  • input 24 is provided to an amplifier 28 via capacitor 30.
  • the power supply VCC and bias resistor 32 are also provided.
  • the output of amplifier 28 is fed to noise cancellation circuitry which may comprise a passive network or be active, for example being implemented using a microprocessor. Noise cancellation circuitry which may be used is not described in this document, as it is known to those skilled in the art.
  • the output from the noise cancellation circuitry is provided to an appropriate output amplifier 34 to be provided to output terminals 36 and 26 which connect to terminals 20 and 22 for the headphone speaker.
  • Figure 2 further explanation of the passive filter network described above is illustrated.
  • the sound transducer 8 in the preferred form of the invention comprises an electret condenser microphone.
  • This microphone behaves as a current source from a signal viewpoint.
  • the microphone signal can be represented as a voltage source in series with the bias resistor, Rbias.
  • the microphone signal is represented as voltage source 40, the output of which is in series with a bias resistor Rbias.
  • the voltage source and bias resistor are in parallel with the passive filter comprising resistor 10 and capacitor 12.
  • the network shown in Figure 2 provides a transfer function which is : 1 + sRC l + s(R + R bi as)C
  • the headphone compensation is determined by targeting the noise cancellation at the best headphone to be catered for and then compensating other headphones to bring them to the same performance level.

Abstract

Headphones, typically for airline passenger use and fitted with noise cancellation microphones, have a filter network attached to each headset to render the response of each microphone at least much of the way towards a normalised impedance/response curve. In this way various manufactures of headphones may be used with an onboard noise cancellation system which is actually optimised for one manufacturers headphones. The filter may be a simple high pass filter and is preferably built in to the headphone.

Description

Noise Cancellation System and Headphone Therefor
TECHNICAL FIELD OF THE INVENTION
The invention relates to noise cancellation systems, and is directed particularly, but not solely, towards a headphone noise cancellation system.
BACKGROUND OF THE INVENTION
Passenger vehicles, particularly commercial aircraft, have seat installations which include appropriate connections, i.e. jacks for receiving connection plugs for headsets and headphones. The user either provides their own, or is provided with, a headset which the user plugs into the jack provided on the relevant seat to listen to various audio channels. The terms headset and headphone are used interchangeably in this document since it is not relevant to the current invention whether a user microphone is fitted.
Recent developments to passenger audio systems include noise reduction systems which use noise reduction headphones or headsets. In one system the seat installation includes active noise cancellation electronic circuitry. The circuitry is operative to provide noise cancellation based on feedback from an appropriate sound transducer such as a microphone which is provided within the headset.
One problem associated with such a system is that noise cancelling electronics needs to be "tuned" to the headset in terms of the sensitivity and frequency response of the headset. Therefore only a narrow range of headset designs are generally able to be used effectively with each of these systems.
PRIOR ART
It is known to provide noise compensation systems with either noise cancellation built into the headphone or with a fixed noise cancellation system forming part of the system into which a headphone is plugged. US patent 5 182 774 exemplifies the former type which have the noise cancellation tailored to each headphone type. The latter have previously been designed for use with only one manufacture of headphone and the noise cancellation is problematic with other types because of variations in frequency response and impedance which render the cancellation ineffective and can, at worst, result in positive feedback and instability.
OBJECT OF THE INVENTION
It is an object of the present invention to provide an improved noise cancellation system, or to provide an improved headset for a noise cancellation system, or to at least provide the public with a useful choice.
SUMMARY OF THE INVENTION
Accordingly in one aspect the invention consists in a noise cancellation system having: a headphone including asound transducer and a headphone speaker, noise cancellation circuitry provided remote from the headphone, supplying the headphone speaker, and being supplied from the sound transducer, a filter to normalise the output from the sound transducer of the headphone to the noise cancellation circuitry.
Preferably the filter is located at the output of the sound transducer to enable effective noise cancellation to be achieved in use. Preferably the filter comprises a passive electronic filter.
Preferably the filter comprises a resistor/capacitor network.
Preferably the filter is a high pass filter in parallel with the sound transducer.
Preferably the sound transducer comprises an electret condenser microphone.
In yet another aspect the invention consists in a headphone for a noise cancellation system, the headphone including, one or more headphone speakers for providing sound to a user. at least one sound transducer provided in the headset adjacent to the speaker, and the output of the sound transducer being provided as an electrical signal and being provided to a filter, and the output of the filter being available to noise cancellation circuitry to cancel noise from the signal being delivered to the speaker.
DRAWING DESCRIPTION
Figure 1 is a circuit schematic of a noise cancellation system according to the invention
Figure 2 is a schematic of an equivalent circuit for a headset microphone and filter according to the invention,
Figure 3 is a schematic for one example of a practical implementation of the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
In general terms, the invention provides a way of allowing noise cancellation circuitry which is typically provided remote from a headphone, to be able to provide effective noise cancellation for a number of different headphone designs. This is achieved by providing the noise cancellation headphone sound transducer (typically a microphone such as an electret condenser microphone) with a passive filter so that the feedback signal provided by the microphone is appropriately conditioned for a "generic" active noise cancellation circuit or normalised. Therefore, the invention allows the noise cancellation circuitry to be designed to be operative over a certain phase range of input feedback signals from a headset. This in turn means that a filter placed on the headset feedback signal may be appropriately configured for each different sort of headset so as to be acceptable to the noise cancellation circuitry and enable collective noise cancellation to be achieved.
The most preferred form of the invention the filter comprises a simple passive filter.
Most preferably it is a resistor/capacitor filter as described further below. We have found that simple resistor capacitor passive filter provides an appropriate transfer function that is suitable for active noise cancellation applications. This simple passive filter may have the values of resistance or capacitance varied dependent upon the nature of the headphone, the headphone sound transducer etc.
Turning now to Figure 1, a schematic of an implementation of the invention as shown. The headphone is shown to the left of dashed line 2 in the figure and is generally indicated by arrow 4. On the other side of the drawing, i.e. to the right hand side of dashed line 2, the noise cancellation circuitry is shown generally referenced 6. By way of example, the noise cancellation circuitry may be provided in a portable electronic device such as a portable audio system including those sold under the trade mark WALKMAN. The circuitry could alternatively be provided in a home stereo system, a television set or a variety of other devices which provide sound to a user. However, more typically, the noise cancellation circuitry 6 will be provided in a passenger vehicle. Again, a number of different forms of passenger transport may be provided so the noise cancellation circuitry may be provided in a seat installation
(possibly an arm rest area) of a commercial aeroplane, a train, a bus. a private automobile, or the like.
In Figure 1 , the sound transducer for the headphone 4 is an electret condenser microphone 8, and the output of the microphone is provided to a passive filter network comprising resistor 10 and capacitor 12. The output from the passive filter network is referenced 14 and 16, and these outputs are typically provided as pins on a plug which is acceptable to an appropriate jack or socket on the device that includes the noise cancellation circuitry. Still referring to Figure 1 , the headset 4 also includes a speaker 18 which has input signal connections 20 and 22. Again, connections 20 and 22 are in use electrically connected to an appropriate plug pins (not shown) so that they can be supplied with an appropriate electrical signal from the output of the noise cancellation circuitry that is provided in the corresponding socket remote from the headphone. Turning now to the noise cancellation circuitry, the input to the noise cancellation circuitry from the microphone is represented by inputs 24 and 26. Input 26 may be a reference such as ground, input 24 is provided to an amplifier 28 via capacitor 30. The power supply VCC and bias resistor 32 are also provided. The output of amplifier 28 is fed to noise cancellation circuitry which may comprise a passive network or be active, for example being implemented using a microprocessor. Noise cancellation circuitry which may be used is not described in this document, as it is known to those skilled in the art. The output from the noise cancellation circuitry is provided to an appropriate output amplifier 34 to be provided to output terminals 36 and 26 which connect to terminals 20 and 22 for the headphone speaker. Turning now to Figure 2, further explanation of the passive filter network described above is illustrated. The sound transducer 8 in the preferred form of the invention comprises an electret condenser microphone. This microphone behaves as a current source from a signal viewpoint. Using a Norton to Thevenin conversion the microphone signal can be represented as a voltage source in series with the bias resistor, Rbias. . In Figure 2, the microphone signal is represented as voltage source 40, the output of which is in series with a bias resistor Rbias. The voltage source and bias resistor are in parallel with the passive filter comprising resistor 10 and capacitor 12. The network shown in Figure 2 provides a transfer function which is : 1 + sRC l + s(R + Rbias)C
This is a suitable transfer function for active noise cancellation applications, i.e. the output from the circuit shown in Figure 2 is appropriate for provision to a "generic" active noise cancellation circuit. Therefore, it can be seen that the values of resistance and capacitance of components 10 and 12 of Figure 2 may be chosen dependent upon the general acoustic properties of the headphone e.g. shape and size of the ear piece and orientation of the microphone relative to the speaker. Finally, in Figure 3, a typically implementation is illustrated. The reference numerals used in this figure are the same as those used with reference to Figure 1 and it can be seen that resistor 10 has value of 3.3kΩ, capacitor 12 is 68 nanofarads, and the bias resistor 32 is 4.7kΩ. Typically the headphone compensation is determined by targeting the noise cancellation at the best headphone to be catered for and then compensating other headphones to bring them to the same performance level. From the foregoing, we see that the invention provides significant advantages in that a number of different headphones or headsets may be used to provide noise cancellation without having to redesign, alter or modify noise cancellation circuitry for which they are used. Therefore, noise cancellation circuitry may be designed to standard parameters and embodied in various devices such as personal stereos or passenger seat installations while allowing users to use their own preferred headset, or a variety of different headsets.

Claims

1. A noise cancellation system having:
a headphone including a sound transducer and a headphone speaker,
noise cancellation circuitry provided remote from the headphone, supplying the headphone speaker, and being supplied from the sound transducer,
characterised in that a filter is provided to normalise the output from the sound transducer of the headphone to the noise cancellation circuitry.
2. A noise cancellation system as claimed in claim 1 characterised in that the filter is located at the output of the sound transducer to enable effective noise cancellation to be achieved in use.
3. A noise cancellation system filter as claimed in claim 2 characterised in that the filter comprises a passive electronic filter.
4. A noise cancellation system filter as claimed in claim 3 characterised in that the filter comprises a resistor/capacitor network.
5. A noise cancellation system filter as claimed in claim 4 characterised in that the filter is a high pass filter in parallel with the sound transducer.
6. A noise cancellation system as claimed in claim 1 characterised in that the sound transducer comprises an electret condenser microphone.
7. A headphone for a noise cancellation system, the headphone including,
one or more headphone speakers for providing sound to a user,
at least one sound transducer provided in the headset adjacent to the speaker, and
characterised in that the output of the sound transducer being provided as an electric signal and being provided to a filter, and the output of the filter being available to noise cancellation circuitry to cancel noise from the signal being delivered to the speaker.
8. A headset as claimed in claim 7 characterised in that the filter is a high pass filter.
PCT/NZ2003/000134 2002-06-28 2003-06-26 Noise cancellation system and headphone therefor WO2004002383A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP2004517418A JP2005531807A (en) 2002-06-28 2003-06-26 Noise canceling system and headphones therefor
DE10392880T DE10392880T5 (en) 2002-06-28 2003-06-26 Noise reduction system and headphones for this
US10/520,036 US7489785B2 (en) 2002-06-28 2003-06-26 Noise cancellation system and headphone therefor
AU2003238975A AU2003238975A1 (en) 2002-06-28 2003-06-26 Noise cancellation system and headphone therefor
GB0428314A GB2406013B (en) 2002-06-28 2003-06-26 Noise cancellation system and headphone therefor

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NZ51986302 2002-06-28
NZ519863 2002-06-28

Publications (1)

Publication Number Publication Date
WO2004002383A1 true WO2004002383A1 (en) 2004-01-08

Family

ID=29997604

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NZ2003/000134 WO2004002383A1 (en) 2002-06-28 2003-06-26 Noise cancellation system and headphone therefor

Country Status (6)

Country Link
US (1) US7489785B2 (en)
JP (1) JP2005531807A (en)
AU (1) AU2003238975A1 (en)
DE (1) DE10392880T5 (en)
GB (1) GB2406013B (en)
WO (1) WO2004002383A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005016204A1 (en) * 2005-04-07 2006-10-12 Sennheiser Electronic Gmbh & Co. Kg Headphone for connection to an external active noise compensation device
US20100061563A1 (en) * 2008-09-08 2010-03-11 Sennheiser Electronic Gmbh & Co. Kg Entertainment system and earphone
US9779714B2 (en) 2008-10-31 2017-10-03 Ams Ag Active noise control arrangement, active noise control headphone and calibration method

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5192901B2 (en) * 2007-10-29 2013-05-08 株式会社オーディオテクニカ Noise canceling headphones
MY151403A (en) * 2008-12-04 2014-05-30 Sony Emcs Malaysia Sdn Bhd Noise cancelling headphone
EP2285135A1 (en) 2009-07-07 2011-02-16 Nxp B.V. Microphone-speaker device comprising a low pass filter
DE102010052833B4 (en) * 2010-11-29 2017-11-23 Austriamicrosystems Ag Circuit arrangement and method for active noise cancellation
KR101194923B1 (en) 2011-04-19 2012-10-25 신두식 Earmicrophone
KR101194904B1 (en) * 2011-04-19 2012-10-25 신두식 Earmicrophone
KR101149981B1 (en) 2011-04-19 2012-05-31 신두식 Earmicrophone
WO2012144706A1 (en) * 2011-04-19 2012-10-26 Shin Doo Sik Ear microphone
GB201519219D0 (en) * 2015-10-30 2015-12-16 Soundchip Sa Noise reduction system
US9871605B2 (en) 2016-05-06 2018-01-16 Science Applications International Corporation Self-contained tactical audio distribution device
KR102512403B1 (en) * 2016-08-19 2023-03-22 삼성전자 주식회사 Electronic device and a method for reducing a noise of audio signal using the same
US10872592B2 (en) 2017-12-15 2020-12-22 Skullcandy, Inc. Noise-canceling headphones including multiple vibration members and related methods
US10484792B2 (en) 2018-02-16 2019-11-19 Skullcandy, Inc. Headphone with noise cancellation of acoustic noise from tactile vibration driver

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993025167A1 (en) * 1992-06-05 1993-12-23 Noise Cancellation Technologies, Inc. Active selective headset
WO1993026084A1 (en) * 1992-06-05 1993-12-23 Noise Cancellation Technologies, Inc. Active plus selective headset
US5815582A (en) * 1994-12-02 1998-09-29 Noise Cancellation Technologies, Inc. Active plus selective headset
WO1999005998A1 (en) * 1997-07-29 1999-02-11 Telex Communications, Inc. Active noise cancellation aircraft headset system
US20030026438A1 (en) * 2001-06-22 2003-02-06 Trustees Of Dartmouth College Method for tuning an adaptive leaky LMS filter

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5732143A (en) * 1992-10-29 1998-03-24 Andrea Electronics Corp. Noise cancellation apparatus
US20010050993A1 (en) * 1997-03-19 2001-12-13 Andrea Douglas Active noise reduction apparatus having a headset with dual stereo jacks and an electronic device having switch means
US7340063B1 (en) 1999-07-19 2008-03-04 Oticon A/S Feedback cancellation with low frequency input
GB2360165A (en) 2000-03-07 2001-09-12 Central Research Lab Ltd A method of improving the audibility of sound from a loudspeaker located close to an ear
US20020141599A1 (en) * 2001-04-03 2002-10-03 Philips Electronics North America Corp. Active noise canceling headset and devices with selective noise suppression
US20030002643A1 (en) 2001-06-29 2003-01-02 Seibel Richard A. Network-attached interactive unified messaging device
EP1438708B1 (en) 2001-10-03 2013-07-03 Koninklijke Philips Electronics N.V. Method for canceling unwanted loudspeaker signals
DE60220696D1 (en) 2001-10-03 2007-07-26 Koninkl Philips Electronics Nv METHOD AND SYSTEM FOR PLAYING SOUND SIGNALS

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993025167A1 (en) * 1992-06-05 1993-12-23 Noise Cancellation Technologies, Inc. Active selective headset
WO1993026084A1 (en) * 1992-06-05 1993-12-23 Noise Cancellation Technologies, Inc. Active plus selective headset
US5815582A (en) * 1994-12-02 1998-09-29 Noise Cancellation Technologies, Inc. Active plus selective headset
WO1999005998A1 (en) * 1997-07-29 1999-02-11 Telex Communications, Inc. Active noise cancellation aircraft headset system
US20030026438A1 (en) * 2001-06-22 2003-02-06 Trustees Of Dartmouth College Method for tuning an adaptive leaky LMS filter

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005016204A1 (en) * 2005-04-07 2006-10-12 Sennheiser Electronic Gmbh & Co. Kg Headphone for connection to an external active noise compensation device
WO2006105974A1 (en) * 2005-04-07 2006-10-12 Sennheiser Electronic Gmbh & Co. Kg Headphones for connection to an external active noise compensation device
US8243942B2 (en) 2005-04-07 2012-08-14 Sennheiser Electronic Gmbh & Co. Kg Headphones for connection to an external active noise compensation device
CN101171880B (en) * 2005-04-07 2013-02-06 森海塞尔电子股份有限及两合公司 Headphones for connection to an external active noise compensation device
US20100061563A1 (en) * 2008-09-08 2010-03-11 Sennheiser Electronic Gmbh & Co. Kg Entertainment system and earphone
US8705761B2 (en) * 2008-09-08 2014-04-22 Sennheiser Electronic Gmbh & Co. Kg Entertainment system and earphone
US9779714B2 (en) 2008-10-31 2017-10-03 Ams Ag Active noise control arrangement, active noise control headphone and calibration method

Also Published As

Publication number Publication date
DE10392880T5 (en) 2005-08-25
JP2005531807A (en) 2005-10-20
GB2406013A (en) 2005-03-16
AU2003238975A1 (en) 2004-01-19
US7489785B2 (en) 2009-02-10
GB2406013B (en) 2006-03-22
GB0428314D0 (en) 2005-01-26
US20050213773A1 (en) 2005-09-29

Similar Documents

Publication Publication Date Title
US8073181B2 (en) Passive headphone equalizing
TW392416B (en) Noise cancellation system for active headsets
WO2004002383A1 (en) Noise cancellation system and headphone therefor
EP2342846B1 (en) Bias arrangement and apparatus
US8660285B2 (en) Accessory adapter for cochlear implant system providing simultaneous T-mic and external audio input
EP3026665B1 (en) Communication apparatus with ambient noise reduction
JP2002501623A (en) Noise cancellation and noise reduction device
US9137609B2 (en) Earphone device with impedance correction unit
US11553291B2 (en) Hearing device with printed circuit board assembly and output transducer
EP2896216B1 (en) Audio communication system
US20100056096A1 (en) Method for driving a ground reference on a signal path, control circuit for driving a ground reference on a signal path, and mobile device
US10945058B2 (en) Balanced stereo headphones with un-balanced air chambers
US20090041259A1 (en) Headphones for Connection to an External Active Noise Compensation Device
US20030179892A1 (en) System and method for an improved configuration for stereo headphone amplifiers
NZ537540A (en) Noise cancellation system and headphone therefor
CN107809693B (en) Double-voice-coil earphone
JP7134472B2 (en) amplifier with speaker
US11804808B2 (en) Sound quality enhancement system and device
US10340872B1 (en) Audio filter device for electronic interference with audio signals
CN2631169Y (en) Apparatus for eliminating contact noise of microphone
US20110044475A1 (en) Audio adapter, earphone and speaker box
EP3931961A1 (en) Sound quality enhancement system and device
CN1438819A (en) Method and apparatus for eliminating touch noise of microphone
US20030025554A1 (en) Headphone amplifier
JP2000228795A (en) Car audio adaptor

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
ENP Entry into the national phase

Ref document number: 0428314

Country of ref document: GB

Kind code of ref document: A

Free format text: PCT FILING DATE = 20030626

WWE Wipo information: entry into national phase

Ref document number: 2004517418

Country of ref document: JP

WWE Wipo information: entry into national phase

Ref document number: 10520036

Country of ref document: US

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase