GB2521173A

GB2521173A - Noise reduction system & method

Info

Publication number: GB2521173A
Application number: GB1321917.5A
Authority: GB
Inventors: Andrew Michael Shardlow
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-12-11
Filing date: 2013-12-11
Publication date: 2015-06-17
Also published as: GB201321917D0

Abstract

A noise reduction system, which can be a communications earplug protection CEP, comprises means for generating a magnetic field and an earplug 5. The earplug comprises an actuator 6, such as a neodymium magnet, arranged to move or vibrate in respond to the magnetic field. The magnetic field may be generated by a voice coil 1 positioned in an earcup 2 disposed over a user's ear. An alternating current may be applied to the coil which generates an audio-frequency changing magnetic field. As the magnet is within this field, the magnet is then driven to vibrate and may be used to communicate with the user. The actuator is preferably located at a first end of the earplug, which may be formed from compressible or expandable material. The invention is suitable for use in head-worn devices such as helmets.

Description

Noise Reduction System & Method This invention relates generally to noise reduction systems, and more particularly to noise reduction systems for use by an individual user requiring protection from noise. The invention is particularly suited, but not limited to, use in head-worn devices such as helmets.

It is well known that the human ear can be damaged by exposure to high levels of noise, leading to a condition known as noise induced hearing loss (NIHL). in a healthy car, the microscopic hair cells found inside the cochlea respond to mechanical sound vibrations by sending an electrical signal to the auditory nerve. However, if a sound reaches 85 dB or stronger, it can cause permanent damage and hearing loss. Moreover, die longer the exposure to high noise levels, the more severe the damage can be.

This is a particular concern for many individuals who are repeatedly exposed to high levels of noise. Some industrial or employment-related environments can expose the individual to loud noises. For example, it is estimated that a tractor that is idling (rather than actively working) is loud enough at 85 dB that it can cause permanent damage after only 8 hours.

Military aircraft have cabin noise levels which far execed safe levels, with 100 dB not being atypical. Other people may experience loud environmental noise due to recreational activities such as attending loud shows and concerts etc. In order to address this issue, many countries have enacted legislation to ensure that workers in noisy environments are provided with some form of hearing protection.

Industries such as the aviation, construction, and manufacturing industries, for example, provide ear protection devices for personnel.

One simple form of hearing protection is an earplug. The earplug is made of a * compressible material which can be inserted into the ear canal, thus attenuating noise and protecting the inner ear. Earplugs can be mouldcd to correspond more accurately with the configuration of an individual's ear, thus increasing comfort and protection. However, in extremely noisy settings it is unlikely that a simple earplug would be able to block enough noise to prevent hearing loss or damage.

Therefore, in some situations the earplug is used in conjunction with some other device such as a helmet. For example, pilots typically use dual hearing protection (i.e. both ears are protected) which consists of an over-car hearing protector and an ear plug. The over-ear hearing protector in a typical aviation helmet has a transducer housed within an ear can' which sits over the pilot's ear.

However, although the earplug in this arrangement provides protection it makes it difficult for the pilot to hear desired (often vital) sounds such as communications from air traffic control. Even with the volume turned up, the user is often unable to hear the desired sound.

One known solution to this problem is to use a Communications Earplug Protection (CEP) system. The CEP consists of a miniature speaker or transducer which is attached to the outside of an expandable foam earplug. The earplug provides a barrier against ancillary noise but also includes a channel through the earplug via which the desired communications can he transmitted. The transducer is connected to a wire which in turn is plugged into a headset or helmet adapter for generating the desired sound.

The advantage of such as system is that desired sounds can be transmitted to the user while some protection is provided against potentially damaging environmental noise. Moreover, such a solution requires rio batteries and can be fitted to a standard aviation helmet or headset.

However, as the transducer is provided on the outside of the ear plug, the hard plastic components press against the user's ear and can be uncomfortable. Moreover, the wires which trail from the transducer pass between the over-ear defence device and the user's head, thus breaking the seal there between and reducing the effectiveness of the device.

Further still, the channel formed along the body of the ear plug reduccs the plug's ability to block environmental noise.

Thus, it is desirable to provide an enhanced noise reduction system which provides effective protection against ancillary or environmental noise whilst enabling a user to hear desired sounds. It is also desirable that such a solution: S * overcomes the discomfort problems associated with the prior art; * is simple to install and use; * does not require batteries; * can be rctro-fittcd to existing hear-worn items such as helmets, over-ear protection devices etc.; * is relatively cheap to manufacture.

Such an improved solution has now been devised.

Thus, in accordance with the present invention there is provided a system, method, head-worn noise reduction device and earplug as defined in the appended claims.

Therefore, in accordance with a first aspect of the invention there is provided a noise reduction system comprising:

means for generating a magnetic field; and

an earplug comprising an actuator arranged to move in response to the magnetic

field.

Preferably, the means for generating the magnetic field comprises a coil, The coil may be a voice coil, The coil may comprise any suitable material such as copper, aluminium, copper-clad aluminium etc. The coil may be configured for communication with a sound source.

The means for generating the magnetic field may comprise means for generating an alternating current (AC). Preferably, the AC is an audio-frequency AC. The AC may be transmitted to the coil such that the coil generates a magnetic field. The actuator (e.g. magnet) may experience an alternating force due to its exposure to the magnetic field, causing the actuator to vibrate. This vibration may be cause a desired sound to be transmitted to the user's inner ear. Thus, the invention may comprise a magnet and a coil arranged such that the magnet can be drivcn to vibrate by the audio-frequency changing

magnetic field produced by the coil.

Preferably, the actuator is a magnet. The magnet may be a rare-earth magnet, such as a neodymium magnet. This provides an advantage over the prior art as fixed magnets are small, lightweight and powerfully driven. The field strength versus mass of a traditional' magnet would provide a less efficieni antngement.

All or part of the actuator may be provided in combination with, or on-board, the earplug.

The actuator may be embedded, completely or partially, within the earplug.

Preferably, the earplug is formed of a compressible material. The earplug may be expandable. It may comprise a foam or sponge-like material. The earplug may be configured to correspond to the shape of a user's ear. Thus, it may bc customiscd to confirm to the configuration of the user's ear to provide a more comfortable and effective fit within the ear. Alternatively, the ear plug may be a generically shaped ear plug i.e. not customised for use with a particular user.

Preferably, the actuator is provided at or towards a first end of the earplug. The first end may be the end which, in use, is inserted into the user's ear such that the first, end is within the user's ear canal and positioned towards the user's ear drum. This enables the desired sound (e.g. communication or broadcast) to be transmitted clearly to the user's inner ear.

Preferably, the means for generating the magnetic field (e.g. voice coil) is positioned adjacent to or in proximity to a second end of the earplug. Preferably, the second end of the ear plug is positioned in use such that it is further away from the user's car drum than the first end of the earplug.

Preferably, the means for generating the magnetic field is positioned relative to the actuator such that the actuator can be made to vibrate by the magnetic field. Thus, it is preferable that the coil is provided such that the actuator (e.g. magnet) is within the magnetic field generated by the means.

Preferably, the means for generating the magnetic field is provided, completely or partially, within a head-worn device or article of clothing. The head-worn device may be a helmet or an over-ear protection device. It may be, for example, an aviation helmet or motorcycle helmet.

Preferably, there is no physical connection between the means for generating the magnetic field arid the earplug or the actuator. Preferably, die interaction between the magnetic field generator and the actuator is effected wirelessly. This provides the advantage that no wires are required between the magnet and the coil, thus overcoming the shortcomings of the

prior art as described above.

The system may be a communication earplug protection system (CEP).

Thus, the invention may provide a solution which: * reduces or eliminates the level of noise which reaches the user's ear, thus protecting the user from hearing loss and damage to the ear; and * allows desired sound (e.g. communication from another party) to be transmitted to the user's ear with clarity.

Also in accordance with the invention there is provided a method which corresponds to the system described above.

Thus, there is provided a noise reduction method, comprising the steps: providing a means for generating a magnetic field; and providing an carping comprising an actuator arranged to move in response to the

magnetic field.

The method may include the step of generating an alternating current (AC). The AC may bean audio-frequency AC. The method may include the step of transmitting the AC to a coil such that the coil generates a magnetic field. The actuator (e.g. magnet) may experience an alternating force due to its exposure to the magnetic field, causing the actuator to vibrate. This vibration may be cause a desired sound to be transmitted to the user's inner ear.

Preferably, the actuator is a magnet. The magnet may be a rare-earth magnet such as a neodymium magnet.

Preferably, the actuator is provided at or towards a first end of the earplug.

Preferably, the means for generating the magnetic field is positioned adjacent to or in proximity to a second end of the earplug.

Preferably, the means for generating the magnetic field is provided at a position relative to the actuator such that the actuator can be made to vibrate by the magnetic field.

The car plug may bc configurcd to correspond to the shape of a user's ear. Thc car plug may be fanned of a compressible and/or expandable material.

The means for generating the magnetic field may be in communication with an amplifier or some other sound source.

Preferably, the means for generating the magnetic field is provided, completely or partially, within a head-worn device or article of clothing. For example, it maybe housed in a helmet or an over-ear device such as ear muffs.

Also in accordance with the invention there is provided a head-worn noise reduction device comprising a noise reduction system as described above. Thus, thc hcad-worn noise reduction device may comprise at least one means for generating a magnetic field; the device may be configured to position the at least one means for generaling a magnetic field relative to a user's ear such that an actuator positioned within the ear can be made to

vibrate by the magnetic field.

The device may comprise a pair of means for generating a magnetic field. Each means may be positioned by the device relative to a respective ear of the user such that respective actuators positioned within the ears can be made to vibrate by the magnetic fields produced by the respective means.

In other words, the device may be configured for use with one or both eats of the user.

Also in accordance with the invention there is provided an earplug comprising a body and a magnet provided in combination with, or on-board, the body. The magnet may be provided, partially or completely, within the body of the earplug.

Preferably, the body is compressible and/or expandable. The body may comprise a foam or sponge-like material.

[he magnet may he a rare-earth magnet. It may he a neodymium magnet.

Thus, the invention may in one sense be summarised as providing a noise reduction solution (or communications earplug protedion CEP) comprising means for generating a magnetic field and an earplug comprising an actuator arranged to respond to the magnetic field. In one embodiment, the actuator is a voice coil positioned near a user's ear and the actuator is a magnet (such as a neodymium magnet) provided in association with the earplug which, in use, is inserted into the user's ear. An alternating current may be the applied to the coil which generates an audiofrequency changing magnetic field. As the magnet may be within this field, the magnet may be driven to vibrate by the magnetic field produced by the coil.

These and other aspects of the present invention will be apparent from and elucidated with reference to, the embodiment described herein.

An embodiment of the present invention will now be described, by way of example only, and with reference to the accompany drawings, in which: Figure 1 illustrates an overview of an embodiment of the invention, comprising a coil and an earplug.

Figure 2 shows an embodiment of the invention in use. In this illustrative embodiment, dual ear protection is provided. Ear plugs are shown after insertion into the user's ear canal and retained in proximity to a voice coil in which an alternating current can he generated.

Figure 3 shows the embodiment of Figure 2 adapted for use within the ear can of an aviation helmet.

Figure 4 shows the invention incorporated into a motorcycle helmet.

Figure 1 shows an overview of the invention in its basic form. Figures 2 to 4 illustrate various possible implementations of the invention for use with different types of heard-rn devices. Howcvcr, it is important to note that the invention is not limited with respect to any particular industry, profession or commercial application. In some applicaLions the invention may be incorporated into a helmet for use with sonic other type of vehicle such as an aviation helmeL (see Figure 3) or a motorbike helmet (see figure 4).

However, the invention may equally be arranged for use in non-vehicular contexts. The invention may be applicable in any context or application area wherein an individani needs to filter or block some degree of environmental noise whilst allowing certain desired sounds to be heard by the user.

It should also be noted that in some embodiments the invention may be used in respect of one ear while in other embodiments dual ear protection may be provided (as shown in figures 2,3 and 4).

In the illustrative embodiment of the figures a transducer, in the tbrm of a voice coil 1, is provided. In figure 3 these are provided within each ear can 2, 3 of an aviation helmet 7.

The voice coil 7 could comprise a copper wire, aluminium wire or copper-clad aluminium wire, It may be coated with an electrical insulation. However, any other metal or material which provides the required functionality of the voice coil may be used. In one illustrative embodiment, the voice coil is a 250 turn coil.

The voice coil has an arrangement for connecting the voice coil to a source 4 capable of generating an audio-frequency alternating current.

A pair of earplugs 5 is provided, one for each voice coil 1. An actuator 6 is provided in each earplug. In the illustrative embodiment, the actuators 6 are neodymium magnets although other types of magnet may be used.

The earplugs 5 comprise a foamy, compressible material to provide comfort thr the user as wcll as providing a snug fit within the ear and maximum noise-reducing functionality.

Each earplug 5 may have a bulbous end 5a to aid in plugging the car canal. In some embodiments, however, the earplug 5 may be customised to fit the shape and dimensions of the individual user's ear.

Each earplug 5 is shaped such that it has two ends, referred to hereinafter as an inner (first) end and an outer (second) end. The magnet 6 is provided at or towards the inner end of the earplug 5.

In use, the user inserts the inner end of each earplug 5 into his ears such that during use the inner ends face towards his ear drums and the outer ends face outwards towards the ear cans. The user then places the helmet over his head such that the ear cans 2, 3 and their respective voice coils I are positioned against or close to the user's ears, This is shown in figures 2 to 4.

An audio-frequency alternating current is generated and applicd to the coil. This in turn creates an audio-frequency magnetic field. If one considers this to be an electromagnet, the poles of the magnet switch polarity at audio-frequency. As the neodymium magnet 6 within the earplug 5 is retained within this field, the magnet 6 experiences an alternating force which causes it to vibrate. In other words, lhe magnet 6 is driven by the magnetic field generated by the coil 1. The sound produced by the vibrations is transmitted down the user's ear canal.

Thus, while the earplug attenuates the environmental noise entering the user's ear, an acceptable sound such as an air traffic control communication is broadcast efficiently from the voice coil to the magnet and then into the user's ear.

In effect, the invention provides a noise reduction solution with an integrated loudspeaker which is simple, effective and comfortable to use.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The word comprising' and "comprises', and the like, does not excludc the prcscnec of elcmcnts or steps other than those listed in any claim or the specification as a whole. In the present specification, "comprises" means "includes or consists of' and "comprising" means "including or consisting of', The singular reference of an element does not exclude the plural reference of such elements and vice-versa. In a device claim enumerating several means, several of these means maybe embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage, -ii-

Claims

CLAIMS: 1. A noise reduction system comprising:means for gcnerating a magnetic field; andan earpiug comprising an actuator arranged to move in response to the magneticfield.
2. A system according to claim I wherein the means for generating the magnetic field is a coil.
3. A system according to claim 1 or 2 wherein the actuator is a magnet.
4, A system according to claim 3 wherein the magnet is a rare-earth magnet, such as a neodymium magnet.
5. A system according to any preceding claim wherein all or part of the actuator is provided in combination with, or on-board, thc earplug.
6. A system according to any preceding claim wherein the earplug is configured to correspond to the shape of a user's ear.
7. A system according to any preceding claim wherein the actuator is provided at or towards a first end of the earplug.
8. A system according to claim 7 wherein the means for generating the magnetic field is positioned adjacent to or in proximity to a second end of the carping.
9. A system according to any prcceding claim wherein the means for generating the magnetic field is positioned relative to the actuator such that the actuator can be madeto vibrate by the magnetic field.
10, A system according to any preceding claim wherein the earplug is fonned of a compressible material.
Ii. A system according to any preceding claim wherein the means for generating the S magnetic field is provided, completely or partially, within a head-worn device or article of clothing.
12. A system according to any preceding claim wherein there is no physical connection between the means for generating the magnetic field and the earplug or thc actuator.
13. A system according to any preceding claim wherein the system is a communication earplug protection system.
14. A noise reduction method, comprising the steps: providing a means for generating a magnetic field; and providing an earplug comprising an actuator arranged to move in response to themagnetic field.
15. A method according to claim 14 wherein the actuator is a magnet.
16. A method according to claim 15 wherein the magnet is a rare-earth magnet such as a neodymium magnet.
17. A method according to claims 14 to 16 wherein the actuator is provided at or towards a first end of the earplug.
18. A method according to claim 16 wherein the means for generating the magnetic field is positioned adjacent to or in proximity to a second end of the earplug.
19. A method according to claims 14 to 18 wherein the mcans for generating the magnetic field is provided at a position relative to the actuator such that thc actuator can bemade to vibrate by the magnetic field,
20. A method according to claims 14 to 19 wherein the ear plug is configured to correspond to the shape of a user's ear
21. A method according to claimsl4 to 20 wherein the ear plug is formed of a compressible and/or expandable material, 22. A method according to claims 14 to 21 wherein the means for generating the magneticfield is in communication with an amplifier.23. A method according to claims 14 to 22 wherein the means for generating the magnetic field is provided, completely or partially, within a head-worn device or article of clothing.24. A head-worn noise reduction device comprising at least one means for generating a magnetic field, (he device being configured to position the at least one means for generating a magnetic field relative to a user's ear such that an actuator positioned within the ear can be made to vibrate by the magnetic field.25. A device according to claim 24 wherein the device comprises a pair of means for generating a magnetic field, each means being positioned by the device relative to a respective ear of the user such that respective actuators positioned within the ears can be made to vibrate by the magnetic fields produced by the respective means.26. An earplug comprising a body and a magnet provided in combination with, or on-board, the body.27. An earplug according to claim 26 wherein the body is compressible and/or expandable.28. An earplug according to claims 26 or 27 wherein the magnet is a rare-earth magnet such a neodymium magnet.Amendments to the Claims have been tiled as tollows CLAIMS: 1. A noise reduction system comprising:means for generating a magnetic field; andan earplug comprising an actuator arranged to move in response to the magnetic fidd.2. A system according to claim 1 wherein the means for generating the magnetic field is a coil.3. A system according to claim 1 or 2 wherein the actuator is a magnet.4. A system according to claim 3 wherein the magnet is a rare-earth magnet. such as a neodymium magnet.5. A system according to any preceding claim wherein all or part of the actuator is provided in combination with, or on-board, the earplug.r 6. A system according to any preceding claim wherein the earplug is configured to correspond to the shape of a user's ear.7. A system according to any preceding claim wherein the actuator is provided at or towards a first end of the earplug.8. A system according to claim 7 wherein the means for generating the magnetic field is positioned adjacent to or in proximity to a second end of the earplug.9. A system according to any preceding claim wherein the means for generating the magnetic field is positioned relative to the actuator such that the actuator can he made tovibrate by the magnetic field.10. A system according to any preceding claim wherein the earplug is formed of a compressible materiaL 11. A system according to any preceding claim wherein the means for generating the magnetic field is provided, completely or partially, within a head-worn device or article of clothing.12. A system according to any preceding claim wherein there is no physical connection between the means for generating the magnetic field and the earplug or the actuator.13. A system according to any preceding claim wherein the system is a communication earplug protection system.14. A noise reduction method, comprising the steps: providing a means for generating a magnetic field; and providing an earplug comprising an actuator arranged to move in response to themagnetic field.15. A method according to claim 14 wherein the actuator is a magnet.r 16. A method according to claim 15 wherein the magnet is a rare-earth magnet such as a neodymium magnet.17. A method according to claims 14 to 16 wherein the actuator is provided at or towards a first end of the earplug.18. A method according to claim 16 wherein the means br generating the magnetic field is positioned adjacent to or in proximity to a second end of the earplug.19. A method according to claims 14 to 18 wherein the means for generating the magnetic field is provided at a position relative to the actuator such that the actuator can he madeto vibrate by the magnetic field.20. A method according to claims 14 to 19 wherein the ear plug is configured to correspond to the shape of a user's ear 21. A method according to claims 14 to 20 wherein the car plug is formed of a compressible and/or expandable material.
22. A method according to claims 14 to 21 wherein the means for generating the magneticfield is in communication with an amplifier.
23. A method according to claims 14 to 22 wherein the means for generating the magnetic field is provided, completely or partially. within a head-worn device or article of clothing.
24. A head-worn noise reduction device comprising at least one means for generating a magnetic field, the device being configured to position the at least one means for generating a magnetic field relative to a user's ear such that an actuator positioned within the ear can be made to vibrate by the magnetic field.
25. A device accordin to claim 24 wherein the device comprises a pair of means for generating a magnetic field, each means being positioned by the device relative to a r respective ear of the user such that respective actuators positioned within the ears can be made to vibrate by the magnetic fields produced by the respective means.