GB2469574A - Hearing protection apparatus with active noise cancellation - Google Patents
Hearing protection apparatus with active noise cancellation Download PDFInfo
- Publication number
- GB2469574A GB2469574A GB1006282A GB201006282A GB2469574A GB 2469574 A GB2469574 A GB 2469574A GB 1006282 A GB1006282 A GB 1006282A GB 201006282 A GB201006282 A GB 201006282A GB 2469574 A GB2469574 A GB 2469574A
- Authority
- GB
- United Kingdom
- Prior art keywords
- acoustic wave
- protection apparatus
- hearing protection
- accordance
- resonator
- 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- Withdrawn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
- 210000000613 ear canal Anatomy 0.000 claims abstract description 9
- 239000000463 material Substances 0.000 claims abstract description 9
- 239000002305 electric material Substances 0.000 claims description 19
- 239000002033 PVDF binder Substances 0.000 claims description 8
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 8
- 229910052744 lithium Inorganic materials 0.000 claims description 6
- 239000003607 modifier Substances 0.000 claims description 6
- UKDIAJWKFXFVFG-UHFFFAOYSA-N potassium;oxido(dioxo)niobium Chemical compound [K+].[O-][Nb](=O)=O UKDIAJWKFXFVFG-UHFFFAOYSA-N 0.000 claims description 6
- 230000004044 response Effects 0.000 claims description 5
- 239000010453 quartz Substances 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 4
- WKBPZYKAUNRMKP-UHFFFAOYSA-N 1-[2-(2,4-dichlorophenyl)pentyl]1,2,4-triazole Chemical compound C=1C=C(Cl)C=C(Cl)C=1C(CCC)CN1C=NC=N1 WKBPZYKAUNRMKP-UHFFFAOYSA-N 0.000 claims description 3
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 3
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 claims description 3
- 229930006000 Sucrose Natural products 0.000 claims description 3
- PILOURHZNVHRME-UHFFFAOYSA-N [Na].[Ba] Chemical compound [Na].[Ba] PILOURHZNVHRME-UHFFFAOYSA-N 0.000 claims description 3
- 229910002113 barium titanate Inorganic materials 0.000 claims description 3
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052797 bismuth Inorganic materials 0.000 claims description 3
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 3
- NKZSPGSOXYXWQA-UHFFFAOYSA-N dioxido(oxo)titanium;lead(2+) Chemical compound [Pb+2].[O-][Ti]([O-])=O NKZSPGSOXYXWQA-UHFFFAOYSA-N 0.000 claims description 3
- 229910000154 gallium phosphate Inorganic materials 0.000 claims description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 3
- YZXCQIOLVHGCFP-UHFFFAOYSA-N lead potassium Chemical compound [K].[Pb] YZXCQIOLVHGCFP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052451 lead zirconate titanate Inorganic materials 0.000 claims description 3
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 claims description 3
- 239000011707 mineral Substances 0.000 claims description 3
- LJCNRYVRMXRIQR-OLXYHTOASA-L potassium sodium L-tartrate Chemical compound [Na+].[K+].[O-]C(=O)[C@H](O)[C@@H](O)C([O-])=O LJCNRYVRMXRIQR-OLXYHTOASA-L 0.000 claims description 3
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 claims description 3
- 235000011006 sodium potassium tartrate Nutrition 0.000 claims description 3
- XMVONEAAOPAGAO-UHFFFAOYSA-N sodium tungstate Chemical compound [Na+].[Na+].[O-][W]([O-])(=O)=O XMVONEAAOPAGAO-UHFFFAOYSA-N 0.000 claims description 3
- 229960004793 sucrose Drugs 0.000 claims description 3
- 239000011031 topaz Substances 0.000 claims description 3
- 229910052853 topaz Inorganic materials 0.000 claims description 3
- 229910000231 tourmaline group Inorganic materials 0.000 claims description 3
- 229910000859 α-Fe Inorganic materials 0.000 claims description 3
- 230000001419 dependent effect Effects 0.000 claims 4
- 239000012876 carrier material Substances 0.000 description 4
- 230000003321 amplification Effects 0.000 description 3
- 230000002238 attenuated effect Effects 0.000 description 3
- 230000033001 locomotion Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 210000000883 ear external Anatomy 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 210000003128 head Anatomy 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229920002379 silicone rubber Polymers 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- 239000007779 soft material Substances 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F11/00—Methods or devices for treatment of the ears or hearing sense; Non-electric hearing aids; Methods or devices for enabling ear patients to achieve auditory perception through physiological senses other than hearing sense; Protective devices for the ears, carried on the body or in the hand
- A61F11/06—Protective devices for the ears
- A61F11/08—Protective devices for the ears internal, e.g. earplugs
-
- 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
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F11/00—Methods or devices for treatment of the ears or hearing sense; Non-electric hearing aids; Methods or devices for enabling ear patients to achieve auditory perception through physiological senses other than hearing sense; Protective devices for the ears, carried on the body or in the hand
- A61F11/06—Protective devices for the ears
- A61F11/14—Protective devices for the ears external, e.g. earcaps or earmuffs
- A61F11/145—Protective devices for the ears external, e.g. earcaps or earmuffs electric, e.g. for active noise reduction
-
- 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
- G10K11/1783—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 handling or detecting of non-standard events or conditions, e.g. changing operating modes under specific operating conditions
- G10K11/17837—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 handling or detecting of non-standard events or conditions, e.g. changing operating modes under specific operating conditions by retaining part of the ambient acoustic environment, e.g. speech or alarm signals that the user needs to hear
-
- 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
- G10K11/1787—General system configurations
- G10K11/17873—General system configurations using a reference signal without an error signal, e.g. pure feedforward
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R17/00—Piezoelectric transducers; Electrostrictive transducers
- H04R17/10—Resonant transducers, i.e. adapted to produce maximum output at a predetermined frequency
-
- 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
- G10K2210/321—Physical
- G10K2210/3227—Resonators
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Health & Medical Sciences (AREA)
- Multimedia (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- Biophysics (AREA)
- Psychology (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Vascular Medicine (AREA)
- Animal Behavior & Ethology (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Audiology, Speech & Language Pathology (AREA)
- Signal Processing (AREA)
- Telephone Function (AREA)
Abstract
Hearing protection apparatus 20 for reducing the intensity of a sound includes: a housing (22) enclosing an acoustic wave convertor 24 for converting an incoming part of the acoustic wave to an electrical signal, preferably by vibration of a piezoelectric sensor; and a signal convertor 32 for converting the electrical signal to an outgoing acoustic wave, preferably by a piezoelectric transducer. The housing (22) is positionable at, within or near to an external auditory canal of an ear (10) of a user and may comprise a resiliently deformable material. The outgoing acoustic wave is arranged to destructively interfere with a part of the incoming acoustic wave that has bypassed the housing (22), to produce a resultant acoustic wave with a reduced amplitude. The acoustic wave converter 24 preferably comprises a plurality of piezoelectric strips of material, which vibrate at different resonant frequencies, linked to corresponding piezoelectric signal converters 32.
Description
Hearing protection apparatus The present invention relates to hearing protection apparatus.
Hearing protection apparatus is used to reduce sound levels experienced by a user in noisy environments, and can take a number of different forms. In some examples, the hearing protection apparatus is in the form of external ear muffs which include sound deadening or insulating material to reduce the intensity of the noise experienced by the user. It is also known to provide "in ear" buds or plugs which are formed of a resiliently deformable, sound insulating plastics material. However, one problem with these types of hearing protection apparatus is that the sound insulation material reduces the intensity levels of all sound frequencies, which makes it difficult for users to hear instructions or alarms.
According to a first aspect of the present invention, there is provided hearing protection apparatus for reducing the intensity of a sound, the sound comprising an acoustic wave, the apparatus including a housing, the housing enclosing an acoustic wave converter for converting an incoming part of the acoustic wave to an electrical signal, and a signal converter for converting the electrical signal to an outgoing acoustic wave, in use the housing being positionable at, within or near to an external auditory canal of an ear of a user, the outgoing acoustic wave being arranged to interfere with a bypass part of the acoustic wave to reduce the amplitude of a resultant acoustic wave sensed by the ear of the user. l S...
Possibly, the housing is at least partially receivable within the external auditory canal. U.s. a II.
The outgoing acoustic wave may be substantially of an opposite or reversed polarity to the incoming part of the acoustic wave, and may have an amplitude which is directly proportional but of reversed polarity to the amplitude of the incoming part of the acoustic wave.
The apparatus may include a power source, which may include power storage, such as a battery. In another embodiment, the power is derived from the incoming part of the acoustic wave, with no additional power supply being provided.
The acoustic wave converter may include an incoming acoustic wave resonator, which may be arranged to vibrate, and may be caused to vibrate by the incoming part of the acoustic wave. Possibly, the incoming acoustic wave resonator may be arranged to vibrate at a predetermined frequency, which may be the resonant frequency of the incoming acoustic wave resonator. The resonant frequency may be substantially the same as the frequency of the incoming part of the acoustic wave.
The signal converter may include an outgoing acoustic wave resonator, which may be arranged to vibrate, and may be caused to vibrate by the electrical signal. Possibly, the outgoing acoustic wave resonator may be arranged to vibrate at a predetermined frequency, which may be the resonant frequency of the outgoing acoustic wave resonator. The outgoing acoustic wave resonator may generate the reversed polarity outgoing acoustic wave by virtue of its orientation relative to the incoming acoustic wave resonator.
Possibly, the apparatus includes a processor for modifying the electrical signal between the acoustic wave converter and the signal converter. Possibly, the outgoing acoustic wave resonator generates the outgoing acoustic wave in response to the signal received from the processor.
The processor may include an amplitude modifier, which may modify the amplitude of the outgoing acoustic wave, and may reverse the polarity of the : 30 the outgoing acoustic wave relative to the incoming part of the acoustic wave. S...
The sound may comprise a plurality of acoustic waves of different frequencies. The acoustic wave converter may be arranged to convert a plurality of the incoming parts of the acoustic waves to a corresponding plurality of the electrical signals. The signal converter may be arranged to convert the electrical signals to a corresponding plurality of outgoing acoustic waves, which are arranged to interfere with a corresponding plurality of the bypass parts of the acoustic waves to reduce the amplitude of the resultant acoustic waves sensed by the ear of the user.
The acoustic wave converter may include a plurality of incoming acoustic wave resonators, each of which may be arranged to vibrate at a predetermined frequency, which may be the resonant frequency of the respective resonator. Each of the predetermined frequencies may be different. Each resonator may vibrate in response to one or more of the incoming parts of the acoustic waves. Each resonant frequency may be substantially the same as the frequency of one of the incoming parts of the acoustic waves.
The or each acoustic wave resonator may include a piezo electric material, which may generate the or each electric signal as the resonator vibrates. Different piezo electric materials may be used for different resonators.
The signal converter may include a plurality of signal converter resonators, each of which may generate an outgoing acoustic wave. Each of the signal converter resonators may be arranged to vibrate at a predetermined frequency, which may be the resonant frequency of the respective resonator. Each of the predetermined frequencies may be different. The number and/or vibration frequencies of the signal converter S.....
* resonators may correspond to the number and/or vibration frequencies of the incoming acoustic wave resonators. *. 30
* The or each resonator may include a piezo electric material which may generate the or each outgoing acoustic wave as the resonator vibrates.
S.....
Different piezo electric materials may be used for different resonators.
The piezo electric material may be selected from the group containing berlinite, cane sugar, quartz, Rochelle salt, topaz, tourmaline-group minerals, gallium orthophosphate, Langasite, barium titanate, lead titanate, lead zirconate titanate, potassium niobate, lithium biobate, lithium tantalite, sodium tungstate, barium sodium niobate, lead potassium niobate, polyvinylidene fluoride, sodium potassium niobate and bismuth ferrite.
The processor may include an amplifier to amplify the electric signal.
The amplitude modifier may be arranged to permit selective modification of different frequencies.
The housing 22 may be formed of a resiliently deformable material.
According to a second aspect of the present invention there is provided a method of protecting hearing, the method including the step of providing hearing protection apparatus for reducing the intensity of a sound, the sound comprising an acoustic wave, the apparatus including a housing, the housing enclosing an acoustic wave converter for converting an incoming part of the acoustic wave to an electrical signal, and a signal converter for converting the electrical signal to an outgoing acoustic wave, in use the housing being positionable at, within or near to an external auditory canal of an ear of a user, the outgoing acoustic wave being arranged to interfere with a bypass part of the acoustic wave to reduce the amplitude of a resultant acoustic wave sensed by the ear of the user. * S I...
The apparatus may include any of the features described in the * ..*** * preceding paragraphs. ****
I *5**
*. 30 Embodiments of the present invention will now be described, by way of : example only, and with reference to the accompanying drawings, in which:-
I
SI.... * .
Fig. 1 is a schematic, part sectional view of a human ear, showing hearing protection apparatus in use; Fig. 2 is a schematic view of part of the hearing protection apparatus; Figs. 3A, 3B and 3C are representations respectively of an acoustic wave, an outgoing acoustic wave, and a resultant acoustic wave; and Fig. 4 is a schematic view of part of another hearing protection apparatus.
Referring to the figures, hearing protection apparatus 20 includes a housing 22, the housing 22 enclosing an acoustic wave converter 24 and a signal converter 32.
The acoustic wave converter 24 includes a plurality of incoming acoustic wave resonators 26, each incoming resonator 26 being formed, in the example shown, of a layer of piezo electric material 50 applied to a carrier material 52. The signal converter 32 includes a plurality of signal converter resonators 34, each of the signal converters 34 being formed of, in the example shown, of a layer of piezo electric material 50 applied to a carrier material 52. The number of signal converter resonators 34 corresponds with the number of incoming acoustic wave resonators 26.
The piezo electric material 50 could be selected from the group containing berlinite, cane sugar, quartz, Rochelle salt, topaz, tourmaline-group minerals, gallium orthophosphate, Langasite, barium titanate, lead titanate, * ..* * lead zirconate titanate, potassium niobate, lithium biobate, lithium tantalite, sodium tungstate, barium sodium niobate, lead potassium niobate, *. 30 polyvinylidene fluoride, sodium potassium niobate and bismuth ferrite. * **
In one example, polyvinylidene fluoride (PVDF) is used as the piezo * electric material. PVDF has been found to provide a piezoelectric effect several times greater than quartz. Thus, PVDF permits the use of smaller apparatus.
Each of the incoming acoustic wave resonators 26 is arranged to vibrate at a predetermined, different frequency. Each of the signal converter resonators 34 is also arranged to vibrate at a predetermined, different frequency. The vibration frequencies of the signal converter resonators 34 correspond with the vibration frequencies of the corresponding incoming acoustic wave resonators 26.
Optimally, the vibration frequency of each respective resonator is arranged to be the resonant frequency of that resonator. Such an arrangement reduces the energy required to vibrate the resonator in each case by a significant amount. In one example, using the arrangement with 1 5 resonant frequency vibration increased efficiency by a factor of 40.
In use, referring to Fig. 2, a sound comprising at least one acoustic wave indicated by arrow A travels towards the hearing protection apparatus 20. As shown in Fig 1, the hearing protection apparatus 20 is located at least partially within the external auditory canal 12 of an ear 10 of the user, so that the housing 22 of the hearing protection apparatus 20 substantially blocks or plugs the entrance to the external auditory canal 12. Advantageously, the housing 22 could be formed of a resiliently deformable, relatively soft material, such as a silicone rubber or a foam plastics material, so that the user can mould or deform the housing 22 to closely fit the auditory canal 12. I...
As shown in Fig. 2, the acoustic wave A splits into two parts, a bypass * part B and an incoming part C. The incoming part C causes at least one of the incoming acoustic wave resonators 26 to vibrate, optimally at its resonant . 30 frequency. The piezo electric material 50 of the resonator 26 converts the * vibration into an electrical signal 28, which is then sent to the corresponding signal converter resonator or resonators 34. The signal 28 could be conveyed between the resonators 26, 34 by any suitable means, such as wiring or a printed circuit board track. In the latter example, the resonators 26, 34 could be mounted to a printed circuit board.
The piezo electric material 50 of the signal converter resonator or resonators 34 converts the electrical signal 28 into a vibration which generates an outgoing acoustic wave D, which is arranged to be reversed in polarity relative to the acoustic wave. Optimally, the vibration of at least one of the signal converter resonators 34 is at its resonant frequency. In this example, the signal converter resonator 34 is arranged to generate the reversed polarity outgoing acoustic wave D by virtue of its orientation relative to the incoming acoustic wave resonator.
The acoustic wave A, the bypass part B and the incoming part C are of substantially the same polarity.
The outgoing acoustic waves D interfere with the bypass part B to form a resultant sound wave E, which has a reduced amplitude relative to the acoustic wave A, thus resulting in a reduction in the intensity of the sound sensed by the user's ear.
The interference of the waves is shown in Figs. 3A, 3B and 3C. These figures show in graphical representations the movement of a particle as the respective wave passes, plotted as displacement of the particle (which for sound waves is a longitudinal movement along the direction of motion of the sound wave) against time. The displacement of the particle shows the amplitude of the respective wave, which is also an indicator of the noise or e.g. sound intensity of the wave.
*.S..I * * Fig. 3A shows the wave form of the bypass part B of the acoustic wave ** 30 A (which is generally similar in form to the wave forms of the acoustic wave A * ** and the incoming part C, if the time between the incoming part C being I.:..: converted by the incoming acoustic wave converter 24 and the generation of **** * the outgoing wave D is similar to the time taken for the bypass part B to travel the length of the hearing protection apparatus 20 which can be assumed to be the case, as the hearing protection apparatus is relatively small). Fig. 3B shows the wave form of the outgoing wave D which has a substantially opposite or reversed polarity relative to the acoustic wave A, the bypass part B and the incoming part C. When the outgoing wave D and the bypass wave B combine or interfere, the resultant wave E has a reduced amplitude as shown in Fig. 3G. The maximum amplitudes of each of the wave forms are indicated by reference numerals 42, 44, 46 respectively. Thus the amplitude 46 of the resultant wave E is the resultant amplitude from the combination of amplitudes 42 and 44. The outgoing acoustic wave D has a wave form which has an amplitude which is directly proportional to the amplitude of the incoming part C, but is of a reversed polarity.
In one example, the reduction in noise or sound intensity experienced 1 5 by the user due to the hearing protection apparatus 20 was approximately 40 dB.
In the apparatus of Fig. 2, it will be noted that the electrical signals 28 are sent directly from the incoming acoustic wave converter 24 to the signal converter 32, without requiring amplification, and also without requiring any power input or additional power supply or power source. The power for exciting the signal converter resonators 34 is derived from the incoming part of the acoustic wave C. In one example, the power generated by the incoming acoustic wave converter 24 is in the range 100 to 900mV.
Necessarily, there is a loss in energy or efficiency loss through the hearing protection apparatus 20, so that the outgoing acoustic wave D has a wave form with a smaller amplitude than the incoming part C. This arrangement is advantageous as it ensures that the sound level sensed by the user is always S. Se : reduced relative to the sound level which would be experienced without the * 30 hearing protection apparatus 20, with no risk of any increase in noise level : * possible. S..
I
S
In the example shown in Fig. 2, the hearing protection apparatus 20 includes eight incoming acoustic wave resonators 26 and eight signal converter resonators 34, which could therefore accommodate eight sound waves A of differing frequencies. In other examples (not shown) the hearing protection apparatus 20 could include any convenient number of incoming acoustic wave resonators 26 and corresponding signal converter resonators 34, from one upwards. In another example, the hearing protection apparatus could include several hundred or more incoming acoustic wave resonators 26 and corresponding signal converter resonators 34.
The advantage of using a plurality of resonators which are arranged to vibrate at different resonant frequencies is that as the resonators resonate naturally at particular frequencies, less power input is required for a greater range of frequencies. However, in one example, a relatively small number of resonators could be provided, which only cover those frequencies which are of particular concern in a particular environment. For example, in many working environments, particular machines emit sound waves with frequencies in the ranges 250 to 500 Hz and 2000 to 8000 Hz, and the hearing protection apparatus could be provided with resonators which are particularly chosen to attenuate those particular frequencies. This would then permit the transmission of sounds with frequencies in the range 500 to 2000Hz to reach the user's ear, sounds in this range including speech and warning signals. In another example, the hearing protection apparatus could include only a single incoming wave resonator and a single signal converter resonator which attenuates only one frequency, which could be of particular concern in a particular environment. S...
* S....
* In other examples, each resonator could be formed entirely of the piezo *..S electric material 50. The carrier material could be selected from any suitable 30 material. In one example, the carrier material could be selected from the * ** group containing diamond-like carbon, silicon, or diamond.
The resonators could be of any suitable size and shape and could be formed of different piezo electric materials 50 to provide the different resonating characteristics, or could be formed of the same piezo electric materials but formed in different shapes or sizes to provide the different resonating characteristics. In one example, the resonators are of a constant length but have differing thicknesses so as to provide different resonant frequency characteristics. In one example, to provide resonators over the audible frequency range of 250Hz to 8kHz, the resonators could be formed of PVDF and could vary in thickness linearly with frequency, ranging from 0.08 microns at 250Hz to 2.64 microns at 8kHz. In another example, the resonators could be of a uniform length of 600 microns.
The frequency range in which the hearing protection apparatus 20 attenuates sound waves could be of any suitable range and in one example 1 5 could be from 20Hz to 20kHz.
Fig. 4 shows part of another hearing protection apparatus 200, many features of which are similar to the hearing protection apparatus previously described. Where features are the same or similar, the same reference numerals have been used, and these features will not be described again for the sake of brevity.
As shown in Fig. 4, hearing protection apparatus 200 includes a signal processor 30 which is located between the acoustic wave converter 24 and the signal converter 32, so that electrical signals 28 from the acoustic wave converter 24 pass through the signal processor 30. The signal processor 30 I...
includes an amplifier 36 and an amplitude modifier 38. The amplifier 36 * ** .** * amplifies the electrical signal 28 from the acoustic wave converter 24. This *.** permits the option of complete cancellation of the bypass acoustic wave B 30 across the range of frequencies for which resonators are provided, since the * * amplifier 36 makes up for energy losses through the acoustic wave converter 24, the signal converter 32 and the connections therebetween. The * * apparatus 200 could include a load limit (not shown) to limit the amplification provided by the amplifier 36 to ensure that over amplification does not occur.
The hearing protection apparatus 200 includes a power supply 40, which could be in the form of a battery of any convenient size and type. The power supply 40 could be located within the housing 22, or could be located remotely from the housing 22, with a suitable connection therebetween.
The amplitude modifier 38 could process the electrical signals 28 to reverse the polarity of the amplitudes of the incoming parts C by proportionately the same amount across the range of frequencies for which resonators are provided. Alternatively in another example, the amplitude could be modified to varying degrees across different frequencies so that the bypass sound wave B is interfered with to a lesser or greater extent at different frequencies. This permits particular problematic frequencies to be attenuated to a different degree relative to potentially useful frequencies.
Thus, for example, those frequencies relating to the highest noise intensity can be attenuated, while those frequencies relating to, for example, human speech, or particular alarm signals, can be attenuated less or not at all. Thus the hearing protection apparatus can be "tuned" to attenuate noise or sound intensity according to the environment being experienced.
Various other modifications could be made without departing from the scope of the invention. The acoustic wave converter and the signal converter could comprise any suitable number of resonators, which could be formed of any suitable material, and could be of any suitable size and shape. The a...
housing of the hearing protection apparatus could be of any suitable size and * shape, and formed of any suitable material.
S a
*. 30 Any of the features of any of the embodiments could be combined in : * any suitable way. a
a..... S *
There is thus provided hearing protection apparatus which provides a number of advantages. The apparatus fits substantially within the external auditory canal of the human ear, providing a high degree of protection for the user's ear, while not substantially protruding outwardly from the user's head, ensuring that the hearing protection apparatus can be easily used with safety helmets or hoods. In one embodiment, the hearing protection apparatus takes power from the incoming acoustic wave, requiring no further power supply.
The hearing protection apparatus of the invention permits attenuation of selected frequencies.
Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or 1 5 shown in the drawings whether or not particular emphasis has been placed thereon. *..* * * *
*.*.** * * * .** * **** * *I* * ** * * * * *****e * *
Claims (29)
- Claims 1. Hearing protection apparatus for reducing the intensity of a sound, the sound comprising an acoustic wave, the apparatus including a housing, the housing comprising an acoustic wave converter for converting an incoming part of the acoustic wave to an electrical signal, and a signal converter for converting the electrical signal to an outgoing acoustic wave, in use the housing being positionable at, within or near to an external auditory canal of an ear of a user, the outgoing acoustic wave being arranged to interfere with a bypass part of the acoustic wave to produce a resultant acoustic wave having a reduced amplitude in comparison to the incoming part of the acoustic wave.
- 2. Hearing protection apparatus in accordance with claim 1, wherein the housing is at least partially receivable within the external auditory canal.
- 3. Hearing protection apparatus in accordance with claim 1 or 2, wherein the housing comprises a resiliently deformable material.
- 4. Hearing protection apparatus in accordance with any preceding claim, wherein the outgoing acoustic wave is substantially of an opposite polarity to the incoming part of the acoustic wave.
- 5. Hearing protection apparatus in accordance with any preceding claim, wherein the apparatus includes a power source.
- 6. Hearing protection apparatus in accordance with any one of claims ito 4, wherein power is derived from the incoming part of the acoustic wave, with * no additional power supply being provided. *.* ** 30
- 7. Hearing protection apparatus in accordance with any preceding claim, * ** wherein the acoustic wave convertor includes an incoming acoustic wave resonator, which is caused to vibrate by the incoming part of the acoustic * wave.
- 8. Hearing protection apparatus in accordance with claim 7, wherein the incoming acoustic wave resonator is arranged to vibrate at a predetermined frequency.
- 9. Hearing protection apparatus in accordance with claim 8, wherein the predetermined frequency is a resonant frequency of the incoming acoustic wave resonator.
- 10. Hearing protection apparatus in accordance with any one of claims 7 to 9, wherein the acoustic resonator generates the electrical signal.
- 11. Hearing protection apparatus in accordance with claim 10, wherein the incoming acoustic resonator comprises a piezo-electric material arranged to generate the electrical signal as the acoustic resonator vibrates.
- 12. Hearing protection apparatus in accordance with any preceding claim, wherein the signal converter includes a signal converter resonator, which is caused to vibrate by the electrical signal.
- 13. Hearing protection apparatus in accordance with claim 12, wherein the signal converter resonator is arranged to vibrate at a predetermined frequency,
- 14. Hearing protection apparatus in accordance with claim 13, wherein the predetermined frequency is the resonant frequency of the signal converter resonator.* ***** * * ** S.
- 15. Hearing protection apparatus in accordance with claim 13 or 14 as 30 ultimately dependent on claim 8, wherein the predetermined frequency of the * ** incoming acoustic wave resonator is substantially the same as the SW: predetermined frequency of the signal converter resonator.S
- 16. Hearing protection apparatus in accordance with any one of claims 12 to 15, wherein the signal converter resonator includes a piezo-electric material arranged to cause the signal converter resonator to vibrate in response to the electrical signal.
- 17. Hearing protection apparatus in accordance with any preceding claim, wherein the apparatus includes a processor for modifying the electrical signal between the acoustic wave converter and the signal converter.
- 18. Hearing protection apparatus in accordance with claim 17, wherein the processor includes an amplitude modifier operable to modify the amplitude of the outgoing acoustic wave by modifying the electrical signal,
- 19. Hearing protection apparatus in accordance with any preceding claim, 1 5 wherein the sound comprises a plurality of acoustic waves of different frequencies, and the acoustic wave convertor is arranged to convert an incoming part of at least one of the acoustic waves to an electrical signal.
- 20. Hearing protection apparatus in accordance with claim 19, wherein the acoustic wave convertor is arranged to convert the incoming parts of a plurality of the acoustic waves to a plurality of electrical signals, the signal convertor being arranged to convert the plurality of electrical signals to a plurality of outgoing acoustic waves.
- 21. Hearing protection apparatus in accordance with any preceding claim, wherein the acoustic wave convertor includes a plurality of incoming acoustic * wave resonators.* ***** * *
- 22. Hearing protection apparatus in accordance with claim 21, wherein ** 30 each of the acoustic wave resonators is arranged to vibrate at a different * ** predetermined frequency. ****SI.. ..* * *
- 23. Hearing protection apparatus in accordance with claim 21 or 22, wherein each acoustic wave resonator is arranged to generate a respective electrical signal.
- 24. Hearing protection apparatus in accordance with any one of claims 21 to 23, wherein each acoustic wave resonator includes a respective piezo electric material, arranged to generate a respective electrical signal as the acoustic wave resonator vibrates.
- 25. Hearing protection apparatus in accordance with any preceding claim, wherein the signal converter includes a plurality of signal converter resonators, each of which is caused to vibrate to generate a respective outgoing acoustic wave in response to an electrical signal.1 5
- 26. Hearing protection apparatus in accordance with claim 25, wherein each of the signal converter resonators is arranged to vibrate at a different predetermined frequency,
- 27. Hearing protection apparatus in accordance with claim 25 or 26, as dependent on any one of claims 21 to 24, wherein the number of the signal convertor resonators is equal to the number of the incoming acoustic wave resonators.
- 28. Hearing protection apparatus in accordance with claim 27, wherein the predetermined frequencies of the signal convertor resonators are substantially the same as the predetermined frequencies of the acoustic wave resonators.SS.....*
- 29. Hearing protection apparatus in accordance with claim 27 or 28, S...wherein the respective electrical signals are output from a respective acoustic 30 wave resonator to a respective signal converter resonator. S *S30. Hearing protection apparatus in accordance with any one of claims 25 a..... -to 29, wherein each signal converter resonator includes a piezo electric material which is operable to cause the signal converter resonator to vibrate in response to an electrical signal.31. Hearing protection apparatus in accordance with claim 11 or any one of claims 12 to 30 as dependent on claim 11, wherein the or each piezo electric material is selected from the group containing berlinite, cane sugar, quartz, Rochelle salt, topaz, tourmaline-group minerals, gallium orthophosphate, Langasite, barium titanate, lead titanate, lead zirconate titanate, potassium niobate, lithium biobate, lithium tantalite, sodium tungstate, barium sodium niobate, lead potassium niobate, polyvinylidene fluoride, sodium potassium niobate and bismuth ferrite.32. Hearing protection apparatus in accordance with any of claims 20 to 31 as dependent on claim 18, wherein the amplitude modifier is arranged to 1 5 selectively modify the amplitude of one or more of the outgoing acoustic waves.33. Hearing protection apparatus substantially as described herein, with reference to the accompanying drawings. * * S...* S. SS. * . S... S... S.. * **SS S S...S * S
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GBGB0906389.2A GB0906389D0 (en) | 2009-04-15 | 2009-04-15 | Hearing protection apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201006282D0 GB201006282D0 (en) | 2010-06-02 |
| GB2469574A true GB2469574A (en) | 2010-10-20 |
Family
ID=40750557
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0906389.2A Ceased GB0906389D0 (en) | 2009-04-15 | 2009-04-15 | Hearing protection apparatus |
| GB1006282A Withdrawn GB2469574A (en) | 2009-04-15 | 2010-04-15 | Hearing protection apparatus with active noise cancellation |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0906389.2A Ceased GB0906389D0 (en) | 2009-04-15 | 2009-04-15 | Hearing protection apparatus |
Country Status (2)
| Country | Link |
|---|---|
| GB (2) | GB0906389D0 (en) |
| WO (1) | WO2010119259A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2020206801B2 (en) * | 2019-01-11 | 2021-08-05 | Hemideina Pty Ltd | Acoustic devices |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0412902A2 (en) * | 1989-08-10 | 1991-02-13 | Mnc, Inc. | Electroacoustic device for hearing needs including noise cancellation |
| FR2734444A1 (en) * | 1995-05-17 | 1996-11-22 | Silec Liaisons Elec | Active ear transducer for low frequency noise cancellation |
| US5812684A (en) * | 1995-07-05 | 1998-09-22 | Ford Global Technologies, Inc. | Passenger compartment noise attenuation apparatus for use in a motor vehicle |
| WO2005046543A1 (en) * | 2003-05-19 | 2005-05-26 | Adaptive Technologies, Inc. | Electronic earplug for monitoring and reducing wideband noise at the tympanic membrane |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2604551B1 (en) * | 1986-09-26 | 1988-12-30 | Saint Louis Inst | NOISE PROTECTION DEVICE |
| EP0333411A3 (en) * | 1988-03-16 | 1991-07-31 | University Of Essex | Headphone assemblies |
| US5740258A (en) * | 1995-06-05 | 1998-04-14 | Mcnc | Active noise supressors and methods for use in the ear canal |
-
2009
- 2009-04-15 GB GBGB0906389.2A patent/GB0906389D0/en not_active Ceased
-
2010
- 2010-04-15 WO PCT/GB2010/000766 patent/WO2010119259A1/en active Application Filing
- 2010-04-15 GB GB1006282A patent/GB2469574A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0412902A2 (en) * | 1989-08-10 | 1991-02-13 | Mnc, Inc. | Electroacoustic device for hearing needs including noise cancellation |
| FR2734444A1 (en) * | 1995-05-17 | 1996-11-22 | Silec Liaisons Elec | Active ear transducer for low frequency noise cancellation |
| US5812684A (en) * | 1995-07-05 | 1998-09-22 | Ford Global Technologies, Inc. | Passenger compartment noise attenuation apparatus for use in a motor vehicle |
| WO2005046543A1 (en) * | 2003-05-19 | 2005-05-26 | Adaptive Technologies, Inc. | Electronic earplug for monitoring and reducing wideband noise at the tympanic membrane |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2010119259A1 (en) | 2010-10-21 |
| GB201006282D0 (en) | 2010-06-02 |
| GB0906389D0 (en) | 2009-05-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10403260B2 (en) | Digital electroacoustic transducer apparatus | |
| RU2580623C1 (en) | Electronic device | |
| CN110177326B (en) | Ultrasonic proximity sensors and related systems and methods | |
| CN103716739A (en) | Method for suppressing sound leakage of bone conduction loudspeaker and bone conduction loudspeaker | |
| WO2007072946A1 (en) | Magnetostrictive device and electronic device | |
| KR20180022912A (en) | Seismic wave device, high frequency front end circuit and communication device | |
| JP2007251358A (en) | Bone conduction speaker | |
| JP5444670B2 (en) | Sound playback device | |
| WO2013175780A1 (en) | Electronic equipment and method of controlling electronic equipment | |
| GB2469574A (en) | Hearing protection apparatus with active noise cancellation | |
| CN116320928A (en) | Bone conduction loudspeaker for suppressing shell leakage | |
| JP6156387B2 (en) | Electroacoustic transducer, manufacturing method thereof, and electronic apparatus using the electroacoustic transducer | |
| CN105959851B (en) | In-Ear high pitch compensates earphone | |
| RU2368099C1 (en) | Hydrophone on surface acoustic waves | |
| JP3143200U (en) | Sound protection equipment | |
| CN205693851U (en) | In-Ear high pitch compensates earphone | |
| KR200364444Y1 (en) | Headphone having sound-absorbing materials built-in | |
| JP6514079B2 (en) | Sound generator | |
| RU2793293C1 (en) | Microphone | |
| JP5475070B2 (en) | Contact microphone | |
| KR100883052B1 (en) | Wireless microphone | |
| WO2023051382A1 (en) | Headphones | |
| KR100542891B1 (en) | Transmitter/Receiver for Radio Communication using PVDF Oscillator | |
| MX2023005370A (en) | Acoustic output device. | |
| KR20200050126A (en) | Proximity sensor for bezel-less type electronic device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |