WO2009072107A2

WO2009072107A2 - Apparatus for imparting hearing ability to babies, children and adults

Info

Publication number: WO2009072107A2
Application number: PCT/IL2008/001532
Authority: WO
Inventors: Moshe Kelly
Original assignee: Moshe Kelly
Priority date: 2007-12-06
Filing date: 2008-11-23
Publication date: 2009-06-11
Also published as: IL187930A0; WO2009072107A3

Abstract

The invention discloses a bone-conduction hearing aid device for providing perception of audio signals to a hearing-impaired user, including an apparatus for converting the audio signals into amplified electromagnetic sound-related signals, a conversion unit for converting the amplified electromagnetic sound-related signals into low amplitude mechanical vibrations for delivery into the mouth of the user, and a housing including an extra-buccal section for the apparatus and an intra-buccal section. The insertion of the intra-buccal section into the mouth provides the perception of the audio signals to the hearing-impaired user.

Description

APPARATUS FOR IMPARTING HEARING ABILITY TO BABIES, CHILDREN AND ADULTS

Field of the Invention

The present invention relates to the field of hearing aids, and more specifically, to the field of hearing aids disposed remotely from the ear, employing bone- conducted vibration mechanisms.

Background of the Invention

Hearing loss is one of the most common chronic medical afflictions with an estimated 300 million impaired persons around the world and 30 million in North America alone. Three out of every 10,000 babies are bom permanently deaf. After walking sticks, hearing aids are the next most widely used assistive technological devices. In Israel, for example, there are an estimated 500,000 people who suffer from some degree of hearing loss or impairment.

As is generally known, the normal perception of sounds in humans results from the outer ear picking up acoustic signals or sound waves, transmitting them to the middle ear through the tympanic membrane, and, in turn, these stimulate the cochlea in the inner ear. These acoustic signals induce electrical impulses, which are transmitted via the auditory nerves to the brain, and there are perceived as intelligible sound. Since the human hearing system encompasses a complicated mix of acoustics, there are consequentially many ways in which the system may be or become defective over time.

Prior art hearing devices are of two major classes: a) conventional air- conduction hearing aids; and b) bone-conduction hearing aids.

Conventional air-conduction hearing aids are a form of simple sound amplifiers, which pick up sound signals with a microphone, convert the sound signals into electrical signals, which, in turn, are amplified and delivered to a loudspeaker placed in the outer ear canal to enhance hearing. This class of hearing aids is generally intended for use in reducing/overcoming the limitations of hearing- impaired users. These hearing aids require user hearing-defined selection and user ear anatomy-defined construction and adjustment.

Ear moulds have to be fitted perfectly to that of the user's ear, yet over time and/or consequential to user activities, such as walking and running, an annoying whistling sound may be generated by the hearing aid. This class of hearing aids tends to be uncomfortable for the users. Conventional hearing aids have also, been known to cause local irritation, skin chaffing and inflammation, and in some cases even an allergic reaction.

Furthermore, it also known in the art that these conventional hearing aids may over-amplify the sound signals, and thus, over time induce a further deterioration in the hearing of some of the users.

Bone-conduction hearing aids known in the art operate on the basis of sound vibration conduction through solids and liquids. Air borne sound wave signals may be picked up by the solid surface and convert them into mechanical vibratory stimuli impingent on the bone structure of the skull and bone surrounding the inner ear. Thus, both the cochlea in the inner ear and the saccule in the vestibular system are stimulated. These stimuli result in the generation and transmission of relative electrical impulses via the auditory nerves C8, to the auditory centres of the brain, where they are perceived as intelligible sound. Bone-conduction hearing aids thus augment the hearing of a hearing-impaired or allow perception of hearing to a deaf person.

The vestibular saccule in humans is generally considered to be the organ responsible for balance and for the determination of movement and acceleration. The vestibular saccule was supposed to be an organ for hearing and certain schools of thought believed that it was the only organ for hearing during the evolutionary period.

In the current evolutionary period, the saccule is still the sole effective hearing organ of fish, amphibia and reptiles, such as the crocodile. These organisms rely solely on mechanical vibration of sound for hearing. U.S. Patent Nos. 4,982,434 and 5,047,994 to Lenhardt, et al., describe the saccular response to audio stimuli, which are transmitted to a human brain via the vestibular nerve, which can substitute or augment hearing and communication in a damaged acoustic nerve in the person's inner ear.

Another patent to Lenhardt is U.S. Patent No. 6,368,267, dated April 9, 2002, describing a stapedial-saccular strut method, wherein a strut connects the medial surface of the stape footplate with the wall of the saccule, thus converting the eardrum vibrations into saccular stimuli by direct coupling, thereby allowing for better stimulation. In the case of deamess, the saccule may therefore serve at least part of the hearing functions of the ear.

Further research showed that there are acoustic responses which originate in the saccule at frequencies and intensities well within the human hearing range. This also holds true in patients with severe sensory-neural loss and impaired functioning of the entire inner ear, provided that the saccule is preserved. It could be concluded that the vestibular response to sound may be used to assist in the rehabilitation of deamess and may further be considered as a serious alternative to a cochleal implant

Auditory sensitivity of the saccule may be useful since the vestibular system is sensitive to low frequency sound stimulation, and thus, is a useful alternative to cochleal implants, taking the greater dynamic range of vestibular signals relative to cochleal signals.

Despite the theoretical known advantages of such bone-conduction hearing aids, however, practical applications thereof and useful devices based upon these advantages are lacking. Many of the devices are bulky and must be worn tightly pressed or anchored firmly against the skull bone or subcutaneously implanted by surgery against or inside a bone within the ear or in the area of the mastoid.

The construction of these devices may increase the likelihood of infection, pain, discomfort, un-aesthetic appearance, danger on impact and psychological uneasiness. Additionally, there are many other drawbacks related to maintenance, adjustment, repair, and replacement of such devices. Examples of such bone conduction devices are described in U.S. Patent No. 4,612,915, to Hough et al.; U.S. Patent No. 5,673,328, to Wandi et al., and U.S. Patent No. 5,735,790, to Hang, Kansson, et al.

Some other bone conduction devices use the teeth as an intermediary for the conduction of mechanical sound vibrations to the skull via title attachment of transducers in permanent contact with one or more teeth by means of adhesion or screws, and rely upon complex miniature radio receiver, which is also placed in the mouth for receiving and processing of the radio signals to be delivered to the transducer, being the means of converting the electrical signals into mechanical vibrations. Apart from the foregoing limitations already described, there may be an added discomfort of having foreign bodies permanently present in the mouth, which may result in difficulty in eating, contamination or poisoning.

Examples of bone conduction hearing aid devices using the teeth or palate bone for the conduction of mechanical sound vibrations to the skull are described in

U.S. Patent No. 5,447,489, to Issalene et al., U.S. Patent No. 5,460,593, to Mersky, et al., U.S. Patent No. 5,913,815, to Ball, et al., U.S. Patent No. 2,161,169, to

Jeffris. Jr., and U.S. Patent No. 5,033,999, to Mersky, et al..

U.S. Patent No. 5,033,999, for example, employs an implanted transducer in a dental post hole drilled into a root canal of a tooth of the user.

Other bone-conduction hearing aids using the transducer vibrations applied to the teeth using a biteplate are described in U.S. Patent No. 5,706,251, to May and

U.S. Patent No. 5,455,842 to Mersky et al. These patents relate to scuba divers' underwater communication incorporating both receiving and transmitting of water conducted audio signals by the diver through a biteplate.

Water-conducted sound conveyance is different to the air conducted sound wave counterpart, in being louder in intensity and having a greater effective wavelength range. Furthermore, when the skin and body of a diver is enveloped and his skull and bones are maintained close water contact, audio vibratory signals are induced which stimulate the cochlea as well as the vestibular saccule to send appropriate signals to the brain to be perceived as sound. These phenomena, however, are generally characteristic of underwater audio communication.

Another bone conduction device using teeth is described in U.S. Patent

No. 5,902,167, to FiIo, et al., wherein pre-recorded sounds are conveyed through edible substances, eating utensils and writing implements through the mouth to the user's ears and provides for the construction of novel amusement devices.

There is thus still a need to provide portable hearing aids and devices, which act as effective hearing aids, based on bone conduction of audio-frequency vibratory impulses, but without the limitations drawbacks and dangers of the prior art devices.

Summary of the Invention

It is an object of the present invention to provide, novel bone-conduction hearing aid-devicesrwhich- convertair^^conducted-audio^{^}signalsrpicked up by sound- processing means to electrical signals, which following amplification thereof, are converted into low amplitude mechanical vibrations. These vibrations are, in some cases, are delivered to the mouth, teeth and palate of babies, children and adults, and in other cases, to the skull of a person with mild, moderate or profound hearing loss, whereby the person is provided with ability to perceive sound of a quality comparable to, or better than, that of the known devices.

One object of the present invention is to impart hearing ability to hearing- impaired babies and children. Another object of present invention is to impart a hearing ability to hearing-impaired adults.

Some embodiments of the present invention provide for devices which are camouflaged by ubiquitous items, such as, but not limited to, a pacifier, a cigarette holder and a hat. A further aspect of the present invention is to alleviate the most common deterrents of conventional hearing aid use, namely the physical discomfort therefrom, the psychological stigma attached to being seen with a conventional hearing aid, and the fear of the device being ruined by humidity and moisture in the ear.

It is also an object of the present invention to provide a mobile and comfortable hearing aid apparatus which does not have any of the limitations, drawbacks and dangers cited in the foregoing description of the prior art.

Another object of the present invention is to provide a relatively simple, inconspicuous and cheap, yet effective configuration, preferably using readily available components.

In accordance with the present invention there is therefore provided a bone- conduction hearing aid device for providing perception of audio signals to a hearing- impaired user, comprising an apparatus for converting the audio signals into ampHfied-elecfromagnetie-sound-relatedrsignals, a conversion unit for-convertingHhe- amplified electromagnetic sound-related signals into low amplitude mechanical vibrations for delivery into the mouth of said user, and a housing including an extra- buccal section for the apparatus and an intra-buccal section, whereby the insertion of said intra-buccal section into the mouth provides the perception of the audio signals to said hearing-impaired user.

In some cases, the apparatus comprises a sound-processing unit for conversion of the audio signals into electrical signals. In some cases, the electrical signals are sound-related analog electromagnetic signals.

According to some embodiments, the device further comprises an amplifier for amplifying the electromagnetic sound related signals received from the sound- processing unit into amplified sound-related analog electromagnetic signals. The amplifier is operative to augment and enhance the analog electromagnetic sound related signals. The conversion unit may comprise a vibration generation means. According to some embodiments, the vibration generation means is housed in the intra-buccal section.

According to some further embodiments, the intra-buccal section comprises a baby pacifier nipple, which nipple may be hollow.

According to some embodiments, the extra-buccal section comprises a substantially cylindrical portion for housing the apparatus and a substantially flat stoppering portion for mounting close to and over a major portion of a surface area of lips of the mouth, thereby preventing the entry of the apparatus into the mourn. Preferably the substantially cylindrical portion is substantially perpendicular to the stoppering portion.

According to some embodiments, the substantially cylindrical portion is disposed substantially along the axis of the intra-buccal section. In some cases, e iπtrar-traccafrsectiorris configured ^orsucking4n-a^eneraUy closed mouth position.

In some embodiments, the mechanism for providing the perception may be selected from: conveying mechanical vibratory stimuli impingent on the bone structure of at least one of the skull and bone surrounding the inner ear of the person, stimulation of the cochlea in the inner ear, stimulation of a saccule in a vestibular system of the person, transmission of audio frequency mechanical impulses from the teeth to the brain via soft tissue and skull foramina of the person, transmission of audio frequency mechanical impulses from the brain onwards via brain fluid channels directly into interconnected inner ear fluids of the person, and combinations of the aforementioned mechanisms.

According to the present invention there is still further provided a bone- conduction hearing aid device for providing a perception of audio signals to a hearing-impaired user, comprising an apparatus for converting the audio signals into low amplitude mechanical vibrations for delivery onto the skull of said user, and an extra-cranial housing for housing the apparatus and for at least partial, suction-fit connection to the skull of said user to provide perception of the audio signals to said hearing-impaired user.

According to some embodiments, the housing is configured as a hat or cap.

Brief Description of the Drawings The invention will now be described in connection with certain embodiments with reference to the following illustrative figures so that it may be more fully understood. To make the drawings clearer and easier for apprehension, the electrical circuit wirings are not shown.

With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural tietails-of the invention in more-detaϋHhan-is-necessary for- a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

In the drawings:

Fig. 1 is a schematic perspective illustration of a bone-conduction hearing aid device in the mouth of a baby, according to an embodiment of the present invention;

Fig. 2 is a schematic longitudinal cross-section view of a bone-conduction hearing aid device, according to an embodiment of the present invention;

Fig. 3 is a simplified diagrammatic representation of an arrangement of the various components of the bone-conduction hearing aid device of Fig. 2;

Fig.4 is a schematic vertical cross-sectional view of a bone-conduction hearing aid device resembling a conventional cigarette holder, according to an embodiment of the present invention; Fig. S illustrates an adult using the device of Fig.4, and

Fig. 6 is a schematic vertical cross-sectional view of a bone-conduction hearing aid device according to further embodiment of the present invention;

Identical numbers in the drawings refer to identical parts.

Description of the Preferred Embodiments

The bone conduction hearing aid device according to the present invention is configured to impart hearing ability to hearing-impaired babies and adults, by using the teeth, gums and palate bones of the hearing impaired person, for the conduction of sound related vibrational stimuli to the skull and inner ear to stimulate at least one of the cochlea and the saccule or both and thus to send impulses to the brain corresponding to the vibrational stimuli, there to be perceived as loud, clear and intelligible sound.

Referencels now made tσ Figs. 1 and 2, whidrare schematicillustrations of a bone-conduction hearing aid device 2. According to some embodiments, the user/ person is a baby or child and the device 2 is camouflaged as a ubiquitous item, illustrated here as a pacifier in the mouth of a baby, comprising an extra-buccal section 3. The extra-buccal section 3 comprises a substantially cylindrical hollow housing 4 having a lid 5 for enclosing at least part of the components and is connected to a substantially flat stoppering portion 6 for mounting close to, and over, a major portion of a surface area of user's lips, thereby preventing entry of the apparatus into said mouth. Typically stoppering portion 6 is annular and is substantially perpendicular to cylindrical hollow housing 4. The pacifier nipple 7 (Figs. 2 and 3) and stoppering portion 6 are typically made of natural rubber or silicone rubber. The functional role of the pacifier is to convey the sound-related vibrations to the teeth, gums and palate bones of the hearing-impaired user, such as, but not limited to, a baby or a child. The nipple 7 of the pacifier is preferably made of a suitably soft, yet vibration-conductive material. Turning now specifically to Figs. 2 and 3, there can be seen a simplified diagrammatic representation of an arrangement of the various components of the bone-conduction hearing aid device 2, according to some embodiments of the present invention. The components typically include two microphones 8, 10, one of which 8, is directional, and the other 10, is non-directional. The device 2 further comprises one or more power sources 12, such as lithium ion rechargeable or other appropriate batteries, to provide operational energy, and a control unit 14 including an on/off volume control swivel switch 15, to control the power utilization of the device. Microphones 8 and 10 detect air-borne sound wave signals, and convert the signals into corresponding analog electromagnetic signals to be delivered, at least in part, to amplifier 16 of the device 2 in a miniaturized audio power amplifier unit configuration. The components should conform to the limited space available, with integrated components capable, without distortion or high power consumption, of accurately amplifying and enhancing the output electrical impulses received from the microphones. In some cases, the output is at a sound pressure level of 110 dB and the frequency range may be 0.2 Hz to 5.0 KHz.

The non-directional microphone 10 is preferably configured with a micro- switch, which can be turned off to provide a directional hearing from directional cardioid microphone 8. This feature allows the hearing-impaired user to shut off background noise in a noisy environment or a room full of conversing people and to concentrate on a person or an audio source of his choice. Detectors of corresponding microphones 8 and 10 are typically located inside the housing 4 to allow free passage of outside airborne sound signals to the microphones. The microphones 8, 10 are configured to pick up air-conducted sound waves to be converted into sound-related electrical signals, appropriately wired to be delivered to the input of an amplifier 16. Amplifier 16 is configured to enhancement the sound-related electrical signals received from the microphones 8 and 10. The electrical output from amplifier 16 is wired to a female "phone jack" socket connector 18, for accommodating the jack 20, thereby promoting the electrical connection of the amplifier 16 to a mechanical vibration generating unit 22. The unit 22 is housed in a rigid or flexible housing 4, which is an extra-buccal section of the device. The vibration generating unit 22 preferably has an increased vibrational capacity, using direct current low power voltage and consumption.

Further seen in Figs. 2 and 3 is a second female socket 24, connected to the electric output of an outside audio source 26, in order to enable a connection of the jack 20 to an outside audio source, such as a tape recorder or compact disc player, instead of the connection to the output of the amplifier 16. This arrangement allows a hearing-impaired person to listen to other audio sources by preference.

The unit 22 converts the analog electromagnetic sound-related signals into relative low amplitude sound-related mechanical vibrations. In some embodiments, the unit 22 converts electrical energy into mechanical energy employing highly magnetostrictive alloys such as TERFENOL-D over frequency ranges of below IHz to the high supersonic range. The unit 22 further comprises a vibration conductor for conducting the generated mechanical sound-related vibrations from the unit 22 to the mouth, teeth and palate bones of the hearing-impaired babies and children via the nipple 7.

Referring now to Figs. 4 and 5 illustrating another embodiment of the present invention to impart a hearing ability to hearing-impaired adults preferably using an adaptation and alteration of the compact hearing aid intended for the use of the hearing impaired babies as described in Figs. 1 to 3, with the replacement of the nipple 7 of the,baby's pacifier with a bite stem 28, and preferably using the housing 4 of the hearing aid device including all its components without any change, to create a new hearing aid device 2. The device 2 resembles a conventional cigarette holder to be held in the mouth and between the teeth of the hearing-impaired user, to obtain a hearing ability by bone conduction as already described, to perceive sound reception of a quality comparable to, or preferably better than, the best known devices. The bite stem 28 of the altered device is preferably made of hard plastic material having an increased vibration conduction ability and preferably cast as an integral part of the housing 4. It is generally known that some materials are better conductors of vibration than others, for instance metals and hard plastics conduct vibrations better than rubber or soft wood.

The devices of the present invention are thus useful in all types of hearing loss and have a relative amplification advantage of 20 decibels (dB) over air conduction hearing aids at the frequency of 250 Hz and a 15dB advantage at 500 Hz, taking advantage of an air/bone gap.

Referring now to Fig. 6, there is seen a schematic cross-sectional view of a bone-conduction hearing aid device 32 comprising an extra-cranial housing, e.g., a hat 34. This embodiment is intended to be the solution to overcome the two most common deterrents of the average hearing-impaired user of the conventional hearing devices: one being the water contamination of expensive and fragile hearing aids, disabling or ruining these devices, and the other, the psychological fear of a social stigma by being identified as a hearing impaired person. It is known that the latter deterrent is very common, causing many hearing-impaired users to totally abstain from buying or using their hearing aids because they are visibly detectable. The device 32 has a capability to automatically disconnect the electrical connection from amplifier 16 to the unit 22 and promote an electrical connection from an outside audio source equipped with a jack (not shown), when the jack is inserted into the female socket 24. This configuration allows the hearing-impaired user to listen to and enjoy hearing an outside audio device.

The device may further comprise a unit 22 including one or more receivers in the form of speakers or a transducer vibrator, bonded firmly to a flexible strut 36, configured with suspension arms 38, with the vibrator receiver being suspended at its rear end with the diaphragm facing the head of the user, when the headwear is worn. The vibrator receives the amplified and enhanced sound-related electrical signals from the amplifier 16. The amplified and enhanced electrical signals received by the unit 22 are converted to relative concurrent low amplitude vibratory impulses which, without being bound to any theory, are believed to be applied to the skull of the hearing-impaired user, thus travelling to the cochlea, and/or to the saccule. In cases where the cochlea is impaired, the impulses may travel by way of the skull foramina and also possibly using a second pathway from there onwards, namely by brain fluid channels directly into interconnected inner ear fluids, thereby inducing hearing.

It is to be understood that the invention is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Those skilled in the art will readily appreciate that various modifications and changes can be applied to the embodiments of the invention as hereinbefore described without departing from its scope, defined in and by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A bone-conduction hearing aid device for providing perception of audio signals to a hearing-impaired user, comprising: an apparatus for converting the audio signals into amplified electromagnetic sound-related signals; a conversion unit for converting the amplified electromagnetic sound-related signals into low amplitude mechanical vibrations for delivery into the mouth of said user, and a housing including an extra-buccal section for the apparatus and an intra- buccal section, whereby the insertion of said intra-buccal section into the mouth provides the perception of the audio signals to said hearing-impaired user.

2. The bone-conduction hearing aid device according to claim 1, wherein said intra-buccal section comprises a baby pacifier nipple.

3. The bone-conduction hearing aid device according to claim 2, wherein said extra-buccal section is configured to prevent entry of said apparatus into the mouth.

4. The bone-conduction hearing aid device according to claim 1, further comprising an amplifier for amplifying the electromagnetic sound-related signals into amplified sound-related analog electromagnetic signals.

5. The bone-conduction hearing aid device according to claim 4, wherein the amplifier is operative to augment and enhance the analog electromagnetic sound- related signals to 110 dB sound pressure level.

6. The bone-conduction hearing aid device according to claim 2, wherein the extra-buccal section comprises a substantially cylindrical portion for housing the apparatus and a substantially flat stoppering portion for mounting close to, and over, a major portion of a surface area of the user's mouth, thereby preventing entry of said apparatus into said mouth.

7. The bone-conduction hearing aid device according to claim 6,wherein the substantially cylindrical portion is perpendicular to the stoppering portion

8. The bone-conduction hearing aid device according to claim 7, wherein the substantially cylindrical portion is disposed along the axis of the intra-buccal section

9. A bone-conduction hearing aid device for providing a perception of audio signals to a hearing-impaired user, comprising ; an apparatus for converting the audio signals into low amplitude mechanical vibrations for delivery onto the skull of the said user, and an extra -cranial housing for housing the apparatus and for at least partial , suction-fit connection to the skull of the said user to provide perception of the audio signals to the said hearing-impaired user.

10. The bone-conduction hearing aid device according to claim 9, further comprising a housing configured as a hat or cap.

11. The bone-conduction hearing aid device according to claim 10, wherein said5 apparatus is mounted inside the housing on a flexible strut-suspension arm.

12. The bone-conduction hearing aid device according to claim 1 , wherein the Intra-buccal section comprises a cigarette holder configuration with a bite stem.

13. The bone-conduction hearing aid device of claim 12, wherein the sound processing means include a directional microphone, and

20. a non directional microphone configured with a built-in electric switch