GB2265790A - Earphone apparatus with active noise reduction - Google Patents
Earphone apparatus with active noise reduction Download PDFInfo
- Publication number
- GB2265790A GB2265790A GB9306667A GB9306667A GB2265790A GB 2265790 A GB2265790 A GB 2265790A GB 9306667 A GB9306667 A GB 9306667A GB 9306667 A GB9306667 A GB 9306667A GB 2265790 A GB2265790 A GB 2265790A
- Authority
- GB
- United Kingdom
- Prior art keywords
- transducer
- sound
- ear
- producing
- enclosure
- 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.)
- Withdrawn
Links
Classifications
-
- 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
-
- 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
- G10K11/17855—Methods, e.g. algorithms; Devices for improving speed or power requirements
-
- 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
- G10K11/17875—General system configurations using an error signal without a reference signal, e.g. pure feedback
-
- 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
- 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
- G10K11/17885—General system configurations additionally using a desired external signal, e.g. pass-through audio such as music or speech
-
- 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
- G10K2210/108—Communication systems, e.g. where useful sound is kept and noise is cancelled
- G10K2210/1081—Earphones, e.g. for telephones, ear protectors or headsets
-
- 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
- G10K2210/3013—Analogue, i.e. using analogue computers or circuits
-
- 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
- H04R1/1008—Earpieces of the supra-aural or circum-aural type
-
- 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
- H04R1/1025—Accumulators or arrangements for charging
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Health & Medical Sciences (AREA)
- Audiology, Speech & Language Pathology (AREA)
- General Health & Medical Sciences (AREA)
- Signal Processing (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
- Headphones And Earphones (AREA)
Abstract
The earphone apparatus protects the ear against excessive levels of noise and comprises a shell 4 which includes a seal 5 for sealing against an ear 3. Internal flanges 12 mount a circuit board g carrying a microphone 2 planar with and immediately adjacent a loudspeaker 1. An active noise reduction feedback circuit 7 located on the circuit board 9 provides anti-phase pressure variations. The spatial arrangement of microphone and loudspeaker produce a cancellation point (8, Fig 1(b)) for sound waves in the enclosure which is close to the ear allowing the use of low specification components in the feedback circuit saving on power consumption. <IMAGE>
Description
EARPHONE APPARATUS
This invention relates to an earphone apparatus and more particularly to such apparatus foi use in an active noise reduction system for the purpose of defending the ear against excessive levels of noise.
The basic concept of electronic ear defenders is well known from GB-A-1530814. A loudspeaker mounted in a shell emits sound waves towards the ear of a wearer and a microphone located between the ear and the loudspeaker picks up noise. The signal from the microphone is fed via a variable gain inverting amplifier and a filter before being used to drive the loudspeaker in anti-phase to produce pressure variations which tend to cancel out pressure variations produced by the noise. This is known as an active noise reduction (ANR) system.
Known ear defenders are used in many different noise environments. For example, they are employed in aircraft to filter out loud vibration noise so as to prevent damage to the ear of the wearer. Similarly, ear defenders are used in industry close to machinery producing loud volume noise to provide protection and comfort for the wearer using the machinery. A problem associated with such ear defenders is that head movement and slight separation of the defender from the ear can let in the noise causing discomfort and disrupting the active noise reduction system.
To improve the performance of ear defenders, a variety of more sophisticated electronics is employed in other known ear defenders to improve and aid the noise cancellation. The extra power demand associated with this type of electronics is normally available from a source of mains or the like power electricity. If not, it is necessary to have long power lines leading to such a power source. However, this can lead to snagging of the lines which can prove just as dangerous as the risk from the noise. Alternatively a number of batteries can be employed. However, they have proved to be heavy, cumbersome and subject to a relatively short life due to the power drain.
It is an object of the present invention to provide an earphone apparatus for use in an active noise reduction system which avoids the drawbacks mentioned above.
According to the present invention there is provided an earphone apparatus for use in an active noise reduction system, the apparatus comprising:
an enclosure for fitting around an ear;
a sensing transducer for sensing sound waves in the enclosure;
a sound producing transducer for producing sound waves in the enclosure;
feedback means for producing a drive signal, in response to sound waves sensed by the sensing transducer, to cause the sound producing transducer to produce sound waves to substantially cancel the sound waves in the enclosure;
wherein the spatial arrangement of the sensing transducer and the sound producing transducer is selected to have a cancellation point for the sound waves in the enclosure at or closely adjacent the ear.
Preferably, the sensing transducer is located adjacent, and in generally the same plane as, the sound producing transducer. Thus, the cancellation point can be easily made to be close to the ear.
Conveniently the sensing transducer is in exactly the same plane as the sound producing transducer since this allows simple mounting of the two components.
Preferably, the sound producing transducer emits sound generally along the axis of the
auditory canal. This is a particularly convenient orientation for the purpose of cancellation performance and mounting of the transducers.
In a preferred embodiment of the invention, the sensing transducer comprises a microphone and the sound producing transducer comprises a loudspeaker. The feedback means preferably comprises a preamplifier for producing an amplified output from the sound waves sensed by said sensing transducer, a filter network for filtering said amplified output, and an ultra low current amplifier for producing said drive signal from the filtered amplifier output. Accordingly, because of the improved performance resulting from the spatial arrangement of the transducers, it is possible to use fewer components.
Furthermore, it is possible to use components which have a lower specification than the prior art components which need to provide a higher gain and a more accurate response curve. These advantages of the present invention provide a reduction in the power demand and also allow the construction of a simple and cost effective active noise cancellation system.
Means can be provided for boosting the level of said drive signal thereby saving on overall power demand of the feedback means.
Preferably, a battery is included for powering the earphone, which battery may conveniently be a rechargeable battery. The apparatus embodying the present invention is able to more manageably use batteries than the prior art due to the aforementioned reduced power demand.
The feedback means, sensing transducer, and sound producing transducer are preferably located on a partition separating the enclosure into a front cavity area adjacent the ear and a rear cavity having substantially the same volume. Thus, performance of the apparatus is further improved.
An example of the present invention will now be described with reference to the accompanying drawings, wherein components common to different figures bear common reference numerals:
Figure 1 (a) schematically illustrates a curve of cancellation points for a spacial arrangement of a sound producing transducer and a sensing transducer used in an known ear defender;
Fiure l(b) schematically illustrates a curve of cancellation points for a spacial arrangement of a sound producing transducer and a sensing transducer used in the earphone apparatus embodying the present invention;
Figure 2 illustrates in more detail the earphone apparatus shown in figure l(b); Figure 3 illustrates a block diagram of the feedback circuit used in the earphone apparatus of figure 2.
Referring to figure l(a), a sound producing transducer, such as a loudspeaker 1, and a sensing transducer, such as a microphone 2, are disposed within a shell 4 which is located in use over an ear 3. The microphone 2 is disposed centrally between the loudspeaker and the ear to sense sound waves (including noise) in the shell 4. Using the electronic circuit of a known active noise reduction system, the loudspeaker is driven to emit cancelling sound waves directed at the ear. The curve A illustrates a curve of the cancellation points for the sound waves in the shell. It should be noted that the curve is located away from the ear and indeed can never get close to the ear.
Referring to figure l(b), the microphone 2 is located to the side adjacent the loudspeaker 1 and in or close to the plane of the loudspeaker diaphragm. When an electronic circuit using an active noise reduction system is employed to drive the loudspeaker, a curve of the cancellation points for the sound waves within the shell 4 is as shown by the curve B.
It should be noted that the curve B is moved closer to the ear than with the prior art curve
A resulting in improved cancellation performance and enabling the cancellation performance at the ear to more closely follow the performance predicted by the active noise reduction system contrary to the arrangement shown in figure l(a). It will be apparent that the spatial arrangement between the sound producing transducer and the sensing transducer relative to the ear can be varied whilst still moving the curve of the cancellation points closer to the ear.
Whereas the prior art has concentrated on the improvement of the performance of the electronics of the active noise reduction technique, the present invention has appreciated that significant improvements in cancellation performance can be provided by altering the spacial position of the cancellation point relative to the ear.
An effect of the improved performance is that lower specification components can be used in the electronics for the active noise reduction system so that the power demand is reduced enabling an earphone apparatus to be produced having a power supply comprising an easily portable battery.
Referring to figure 2, an earphone apparatus comprises the shell 4 which includes a seal 5 for sealing against the ear 3. The shell includes internal flanges 12 to which is mounted a circuit board 9. A front cavity foam piece 13 is sandwiched between the seal 5 and the flanges 12 to define a front air volume 10. The circuit board 9 mounts the loudspeaker 1 with the microphone 2 mounted immediately adjacent thereto and in the same plane as the loudspeaker diaphragm. A feedback circuit 7 comprising the active noise reduction system is also located on the circuit board 9 and is powered via a lead 8 connectable to a rechargeable battery (not shown). A rear cavity foam piece 6 is sandwiched between the shell 4 and the circuit board 9 to define a rear air volume 11. The front air volume 10 is preferably the same as the rear air volume 11.
Referring to figure 3, the feedback circuit 7 comprises a pre-amplifier 20 connected to receive the output that the microphone 2 produces in response to the sound waves in the shell 4. The amplified signal from the pre-amplifier is supplied to a filter network 21 to filter the signal. The filtered output from the network 21 is then connected to a very low current amplifier 22. The very low current amplifier produces a drive signal which is connected via a resistor 23 to be inverted on connection to the loudspeaker 1. It will be apparent that the inversion can be achieved by reverse connecting the loudspeaker.
Transistors 24 and 25 connect with their bases on one side of the resistor 23 and their
emitters on the other side of resistor 23. In this way, the transistors act as a current booster to provide the necessary current boost to the output of the amplifier 22 when needed, because the amplifier being a low quiescent current device has limited ability to
drive the loudspeaker. Power for the various components derives from a rail 26 connected to the rechargeable battery via the lead 8.
In the feedback circuit 7, whilst the feedback equations etc of the active noise reduction system apply up to a point, it is the spacial arrangement of the loudspeaker and microphone that ensures that the noise reducing performance at the ear can follow the performance predicted by the feedback equations. With the present invention, the improvement is in the actual noise reduction as heard by the user.
The improved cancellation performance of the present invention allows the use of very low power amplification and the reduced requirement for amplification tends to reduce the detrimental effects of head movements and breaking of the seal 5 from the ear compared with prior art. The present invention has appreciated that since the microphone samples sound rather than electricity, the microphone is essentially a servo mechanism which is acting upon the physics of the air within the shell. The microphone which is responsible for reducing distortion and AC/DC offsets (the outside noise can be classed as a distortion or AC offset) has been placed to improve performance within the acoustic confines of the shell.This factor allows lower gain/specification electronic components to be employed compared with the prior art whilst keeping the actual acoustic performance at a good level, certainly appropriate to the noise reduction required for the present use. Moreover, the power consumption can be reduced due to the less complex circuitry and lower overall gain required compared with the prior art.
For example, referring to figure 3, under zero or low noise conditions, the quiescent power consumption of the feedback circuit 7 can be less than 4 mA which gives a battery life from a typical PP3 of around 120 hours. Under real transient noise conditions, the circuit rarely works near full power and even at external noise levels of around 110 dB the average power consumption would be typically 14 mA giving a battery life of around 34 hours. Using a rechargeable battery, a life expectancy of around 8 hours can be possible.
This low power consumption makes the present invention particulary suitable for real working environments.
It will be apparent that a microphone, external to the shell 4, can be connected via a compressor circuit into the feedback circuit between the filter network 21 and the low current amplifier 22. The connection would normally comprise a mixer unit and the compressor circuit would reduce variable external noise to a constant level. However, voice signals would pass through to be amplified and produced from the loudspeaker.
Thus, an earphone apparatus can be produced which not only defends the ear against excessive noise levels, but also allows voice signals to be heard.
Claims (11)
1. An earphone apparatus for use in an active noise reduction system, the apparatus comprising:
an enclosure (4) for fitting around an ear;
a sensing transducer (2) for sensing sound waves in the enclosure;
a sound producing transducer (1) for producing sound waves in the enclosure;
feedback means (7) for producing a drive signal, in response to sound waves sensed by the sensing transducer, to cause the sound producing transducer to produce sound waves to substantially cancel the sound waves in the enclosure; characterised in that
the spatial arrangement of the sensing transducer and the sound producing transducer is selected to have a cancellation point for the sound waves in the enclosure at or closely adjacent the ear.
2. Apparatus as claimed in claim 1 wherein the sensing transducer is located adjacent, and in generally the same plane as, the sound producing transducer.
3. Apparatus as claimed in claim 2 wherein the sensing transducer is in exactly the same plane as the sound producing transducer.
4. Apparatus as claimed in any preceding claim wherein the sound producing transducer emits sound, in use, generally along the axis of the auditory canal.
5. Apparatus as claimed in any preceding claim wherein the sensing transducer comprises a microphone and the sound producing transducer comprises a loudspeaker.
6. Apparatus as claimed in claim 5 wherein the feedback means comprises a preamplifier (20) for producing an amplified output from the sound waves sensed by said sensing transducer, a filter network (21) for filtering said amplified output, and an ultra low current amplifier (22) for producing said drive signal from the filtered amplifier output.
7. Apparatus as claimed in claim 6 further comprising means (23, 24, 25) for boosting the level of said drive signal.
8. Apparatus as claimed in claim 6 or 7 further comprising an external microphone connected via an electronic compression means to said ultra low current amplifier.
9. Apparatus as claimed in any preceding claim including a battery for providing electric power to the apparatus.
10. Apparatus as claimed in claim 9 wherein the battery comprises a rechargeable battery.
11. Apparatus as claimed in any preceding claim wherein said feedback means, sensing transducer, and sound producing transducer are located on a partition separating the enclosure into a front cavity area (10) adjacent the ear in use and a rear cavity (11) having substantially the same volume.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9306667A GB2265790A (en) | 1992-04-02 | 1993-03-31 | Earphone apparatus with active noise reduction |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB929207243A GB9207243D0 (en) | 1992-04-02 | 1992-04-02 | Earphone apparatus |
| GB9306667A GB2265790A (en) | 1992-04-02 | 1993-03-31 | Earphone apparatus with active noise reduction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9306667D0 GB9306667D0 (en) | 1993-05-26 |
| GB2265790A true GB2265790A (en) | 1993-10-06 |
Family
ID=26300630
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9306667A Withdrawn GB2265790A (en) | 1992-04-02 | 1993-03-31 | Earphone apparatus with active noise reduction |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2265790A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994017513A1 (en) * | 1993-01-29 | 1994-08-04 | Active Noise And Vibration Technologies, Inc. | Earpiece for active noise cancelling headset |
| EP0655730A1 (en) * | 1993-11-30 | 1995-05-31 | Koninklijke Philips Electronics N.V. | Magnetic resonance imaging apparatus comprising a communication system |
| US5675658A (en) * | 1995-07-27 | 1997-10-07 | Brittain; Thomas Paige | Active noise reduction headset |
| EP0967592A2 (en) * | 1993-06-23 | 1999-12-29 | Noise Cancellation Technologies, Inc. | Variable gain active noise cancellation system with improved residual noise sensing |
| US6278786B1 (en) * | 1997-07-29 | 2001-08-21 | Telex Communications, Inc. | Active noise cancellation aircraft headset system |
| US7103188B1 (en) | 1993-06-23 | 2006-09-05 | Owen Jones | Variable gain active noise cancelling system with improved residual noise sensing |
| WO2008062275A1 (en) * | 2006-11-22 | 2008-05-29 | Nordicneurolab As | Audio apparatus for use withing magnetic resonance imaging systems |
| US8391530B2 (en) | 2009-01-16 | 2013-03-05 | Sennheiser Electronic Gmbh & Co. Kg | Helmet and apparatus for active noise suppression |
| CN104602156A (en) * | 2015-01-27 | 2015-05-06 | 歌尔声学股份有限公司 | Earphone speaker and earphone with speaker |
| CN105554608A (en) * | 2015-12-23 | 2016-05-04 | 戴进贵 | Noiseproof earphone |
| GB2577297A (en) * | 2018-09-20 | 2020-03-25 | Deborah Caroline Turner Fernback | Ear-and-eye mask with noise attenuation and generation |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1530814A (en) * | 1977-06-20 | 1978-11-01 | British Aircraft Corp Ltd | Hearing protection devices |
| US4494074A (en) * | 1982-04-28 | 1985-01-15 | Bose Corporation | Feedback control |
| US4833719A (en) * | 1986-03-07 | 1989-05-23 | Centre National De La Recherche Scientifique | Method and apparatus for attentuating external origin noise reaching the eardrum, and for improving intelligibility of electro-acoustic communications |
| EP0468610A2 (en) * | 1990-07-27 | 1992-01-29 | Mnc, Inc. | Method and apparatus for performing noise cancelling in headphones |
-
1993
- 1993-03-31 GB GB9306667A patent/GB2265790A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1530814A (en) * | 1977-06-20 | 1978-11-01 | British Aircraft Corp Ltd | Hearing protection devices |
| US4494074A (en) * | 1982-04-28 | 1985-01-15 | Bose Corporation | Feedback control |
| US4833719A (en) * | 1986-03-07 | 1989-05-23 | Centre National De La Recherche Scientifique | Method and apparatus for attentuating external origin noise reaching the eardrum, and for improving intelligibility of electro-acoustic communications |
| EP0468610A2 (en) * | 1990-07-27 | 1992-01-29 | Mnc, Inc. | Method and apparatus for performing noise cancelling in headphones |
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994017513A1 (en) * | 1993-01-29 | 1994-08-04 | Active Noise And Vibration Technologies, Inc. | Earpiece for active noise cancelling headset |
| US7103188B1 (en) | 1993-06-23 | 2006-09-05 | Owen Jones | Variable gain active noise cancelling system with improved residual noise sensing |
| EP0967592A2 (en) * | 1993-06-23 | 1999-12-29 | Noise Cancellation Technologies, Inc. | Variable gain active noise cancellation system with improved residual noise sensing |
| EP0967592A3 (en) * | 1993-06-23 | 2000-03-15 | Noise Cancellation Technologies, Inc. | Variable gain active noise cancellation system with improved residual noise sensing |
| US6118878A (en) * | 1993-06-23 | 2000-09-12 | Noise Cancellation Technologies, Inc. | Variable gain active noise canceling system with improved residual noise sensing |
| EP0655730A1 (en) * | 1993-11-30 | 1995-05-31 | Koninklijke Philips Electronics N.V. | Magnetic resonance imaging apparatus comprising a communication system |
| BE1007806A3 (en) * | 1993-11-30 | 1995-10-24 | Philips Electronics Nv | A magnetic resonance apparatus comprising a communication system. |
| US5552708A (en) * | 1993-11-30 | 1996-09-03 | U.S. Philips Corporation | Magnetic resonance imaging apparatus comprising a communication system |
| US5675658A (en) * | 1995-07-27 | 1997-10-07 | Brittain; Thomas Paige | Active noise reduction headset |
| US6278786B1 (en) * | 1997-07-29 | 2001-08-21 | Telex Communications, Inc. | Active noise cancellation aircraft headset system |
| WO2008062275A1 (en) * | 2006-11-22 | 2008-05-29 | Nordicneurolab As | Audio apparatus for use withing magnetic resonance imaging systems |
| US8085942B2 (en) | 2006-11-22 | 2011-12-27 | Nordicneurolab As | Audio apparatus and method for use in proximity to a magnetic resonance imaging system |
| US8391530B2 (en) | 2009-01-16 | 2013-03-05 | Sennheiser Electronic Gmbh & Co. Kg | Helmet and apparatus for active noise suppression |
| CN104602156A (en) * | 2015-01-27 | 2015-05-06 | 歌尔声学股份有限公司 | Earphone speaker and earphone with speaker |
| CN105554608A (en) * | 2015-12-23 | 2016-05-04 | 戴进贵 | Noiseproof earphone |
| GB2577297A (en) * | 2018-09-20 | 2020-03-25 | Deborah Caroline Turner Fernback | Ear-and-eye mask with noise attenuation and generation |
| GB2577297B (en) * | 2018-09-20 | 2021-01-20 | Deborah Caroline Turner Fernback | Ear-and-eye mask with noise attenuation and generation |
| US11688380B2 (en) | 2018-09-20 | 2023-06-27 | Deborah Caroline Turner-Fernback | Ear device with dynamic noise attenuation and generation |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9306667D0 (en) | 1993-05-26 |
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