Low sound attenuating hearing protection device with filter arrangement

(54) Title: HEARING PROTECTION DEVICES AND METHOD OF MANUFACTURING A HEARING PROTECTION DEVICE (30) Unionist Priority: 02/09/2007 us 11 / 704,475 (73) Owner (s): 3M Innovative Properties Company (72) Inventor ( es): Marc l. Doty (74) Attorney (s): Alexandre Fukuda Yamashita (86) International Request: pct US2008001607de 07/02/2008 (87) International Publication: wo 2008 / i00407de 21/08/2008 (57) Summary: hearing protection devices and METHOD OF MANUFACTURING A HEARING PROTECTION DEVICE. The present invention relates to a hearing protection device that includes a sound attenuating portion configured to be arranged within a user's ear canal to obstruct the passage of sound, a channel formed through the sound attenuating portion configured to allow that sound passes through the sound attenuating portion, when the portion is disposed within the ear canal, a tube arranged in the channel and configured to allow the sound in the channel to pass through it, and a filter disposed on one end of the tube and positioned inside the sound attenuating portion, the filter attenuating part of the sound that passes through the tube.

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ΡΙ0806441-5 “HEARING PROTECTION DEVICES AND MANUFACTURING METHOD

OF A HEARING PROTECTION DEVICE ”

Field of the Invention Technique

The invention relates to hearing protection devices and, more particularly, to hearing protection devices that provide low or relatively reduced sound attenuation.

Description of the Related Art

Hearing protection devices, such as ear protectors and semi-ear devices, are readily used to provide attenuation of sounds. Such devices are inserted into a user's ear canal, or placed over the opening of the ear canal, to physically block the passage of sound waves into the inner ear.

Earplugs include any of a variety of devices designed to be inserted into a user's ear canal and used to prevent sound from entering. Push-in ear protectors comprise an attenuating portion and a rigid or semi-rigid portion that typically extends from or is embedded in it. The sound attenuation portion may be a rubber, plastic, or foam material, the rigid or semi-rigid portion may be composed of any material, such as plastic or rubber, with sufficient stiffness as needed. To insert the push-in type ear protector, the user holds the rigid / semi-rigid portion (or one end of the ear protector adjacent to it), positions the ear protector close to the opening of the ear canal, and inserts the sound attenuating portion within the channel by pushing the rigid / semi-rigid portion. The sound attenuating portion compresses, as necessary, after entering the ear canal and is held in place by a friction fit, closing the canal and thereby attenuating the sound.

Such a push-in ear protector can be found, for example, in US patents No. 4,867,149 and 5,188,123, attributed to Falco and Gardner Jr., respectively, with their complete content being incorporated here, the reference title.

Moldable earmuffs are also known. Such earmuffs simply comprise a portion of compressible resilient material produced from a rubber, plastic, or, preferably, a foam material. The body part is typically cylindrical or semi-cylindrical in shape and includes a circular cross section that has a diameter larger than that of a user's ear canal. Insertion is achieved, first, by compressing the body part to a diameter smaller than that of the ear canal, secondly, by pushing the body part into it, and, thirdly, allowing it expands slightly to fill the ear canal, thereby obstructing the ear canal and preventing the passage of sound.

Such moldable earmuffs can be found, for example, in US patent No. 6,105,715, attributed to Knauer, with the complete content of which is incorporated herein by reference.

The semi-auricular devices comprise a curved band having a first and second ends, and a sound attenuating element arranged at each of said first and second ends. The curved strip is generally composed of a rigid or semi-rigid plastic or rubber material, while the sound attenuating elements are formed from a compressible resilient material such as rubber, plastic, or foam-like material. The sound attenuating elements are generally inserted into the user's ear canal by the push-in technique described above, with reference to the push-in type earmuffs. When sound attenuating elements are properly inserted into the ear canal, the curved band that connects the elements can be worn by the user as desired, for example over the head, below the chin, behind the neck, etc. Such a semi-auricular device is described, for example, in US Patent No. 4,461,290, assigned to Gardner, with the complete content of which is incorporated herein by reference.

The hearing protection devices described have been designed and developed to provide a high degree of sound attenuation. In many cases, when a proper adjustment of the device is obtained, this results in an almost complete attenuation of the sound. For example, moldable earmuffs commercially available under the trademark EAR Classic and

EAR Ultrafit provide a sound attenuation that has a single noise reduction rate (SNR) of approximately 28dB and 32dB, respectively.

Often, however, an attenuation of lower sounds is desired. That is, applications exist when a user wants sound to penetrate through the hearing protection device and pass through the ear canal to the inner ear. In this way, a degree of hearing protection can be provided, but the user can still hear sounds.

A hearing protection device with such characteristics is desired, for example, in moderately noisy industrial locations where it is up to a user to hear noise in the workplace while still being given a level of hearing protection. For example, a worker on a manufacturing floor may want to hear voice communication from a colleague or the sounds of a moving truck, etc. In this case, the total or near total sound attenuation provided by several common earplugs is not desirable.

Thus, a protector with less attenuation is desired.

Hearing devices, particularly ear protectors, are known in the art, and include provisions for reducing attenuation levels. See, for example, US Patent Application Serial No.

10 / 700,213, filed on November 3, 2003, entitled Low Sound Attenuating Hearing Protection Device, with the complete content of which is incorporated herein, as a reference. Application 10 / 700.213 discloses a hearing protection device comprising a portion of sound attenuation for insertion in the ear, which includes a channel formed through it. The sound attenuation portion of the hearing protection device closes the ear canal, thereby attenuating the sound. The channel, on the other hand, allows sound to pass through the sound attenuator element and propagate to a user's inner ear. The overall effect is a hearing protection device that provides reduced sound attenuation. For example, the hearing protection device provides an SNR (unique noise reduction rate number) value of about 20. This is significantly reduced in relation to the attenuation provided (about 32 SNR) by the hearing protection device of order 10 / 700.213, if produced without the channel.

It is often desired to maintain reduced attenuation across a wide range of frequencies, such as between 63 - 8,000 Hz. Some previous attempts in this range have resulted in a low to moderate attenuation of higher frequencies, but at lower frequencies, they have not provided attenuation. enough. Some hearing protection devices have been developed, which can provide reduced attenuation over a wide range of frequencies, but they require expensive filters, damping elements, and / or electronic arrangements, and are complicated to manufacture and assemble.

Consequently, a hearing protection device is desired to consistently and effectively provide attenuation of low sounds to a user's ear over a wide range of frequencies, including lower frequencies, and that is easy to manufacture, at a cost. effective, and that is durable.

Brief Description of the Invention What has been discussed above and other problems and deficiencies of the prior art are overcome or alleviated by the invention, which provides a hearing protection device, including a sound attenuating portion configured to be arranged within a user's ear canal for obstruct the passage of sound, a channel formed through the sound attenuating portion, configured to allow sound to pass through the sound attenuating portion when the portion is disposed within the ear canal, a tube disposed in the channel and configured to allow sound in the channel to pass through it, and a filter disposed at one end of the tube and positioned inside the sound attenuating portion, where the filter attenuates a part of the sounds that pass through the tube.

The invention additionally provides a hearing protection device that includes a sound attenuating portion configured to be arranged within a user's hearing channel, to obstruct the passage and sound, a channel formed through the sound attenuating portion, generally along a longitudinal axis thereof, the channel being configured to allow sound to pass through the sound attenuating portion, when the portion is disposed within the ear canal, a thin filter membrane disposed in the channel within the sound attenuating portion, the filter including a plurality of openings that delimit areas of airflow resistance, configured to attenuate the sound that passes through the channel.

The invention also provides a manufacturing method for the hearing protection device. The method in one embodiment generally includes the formation of a sound attenuating element that has a first and second opposite ends, and the formation of a channel through the sound attenuating element from the first end to the second end, providing a flexible filter membrane. at a first open end of a tube, such that the side edges of the filter membrane extend beyond the diameter of the tube, inserting the filter membrane and the first end of the tube into the channel at the first end of the sound attenuator element, tilting the side edges of the filter towards the second opposite end of the tube and bringing the side walls of the filter into contact with the outer surface of the filter tube, and pushing the tube into the channel, such that the first end of the tube and the filter are completely arranged within the sound attenuator element, and in such a way that the lateral edges of the tube are arranged in a friction fit between the outer surface of the tube and a surface of the sound attenuating portion that delimits the walls of the channel.

Brief Description of Drawings

Reference is made, at the moment, to the drawings and similar elements are numbered in the same way in the various figures:

Figure 1 is a perspective view of an ear protector, in an embodiment of the invention, Figure 2A is a cross-sectional view of the ear protector of Figure 1, Figure 2B is a partial enlarged view of Figure 2A, a figure 2C is a view of a tube and a filter, in an exemplary embodiment of the invention, figure 2D is a cross-sectional view of the ear protector of figure 1, in another embodiment of the invention, figure 3 is a front elevation view of the ear protector of figurei, figure 4 is a perspective view of an ear protector, in a second embodiment of the invention, figure 5 is a cross-sectional view of the ear protector

Ί of figure 4, figure 6 is a perspective view of an ear protector, in a third embodiment of the invention, figure 7 is a cross-sectional view of the ear protector of figure 6, figure 8 is a view in cross section of the ear protector of figure 6, in another embodiment of the invention, figure 9 is a perspective view of a semi-auricular hearing protection device, Figure 10 is an enlarged cross-sectional view of a portion of the semi-auricular device of Figure 9, and Figure 11 is an enlarged cross-sectional view of a portion of the semi-auricular device of Figure 10, in another embodiment of the invention. .

Detailed description of the invention

Figures 1 to 3 show a hearing protection device in an embodiment of the invention. In particular, an ear protector 2 is shown including flanges 4 from an elongated support member 6. The support member 6 has a first end 8, from which the first flanges 4 emanate, and an opposite second end 10, which extends longitudinally beyond flanges 4. The flanges 4 are substantially hemispherical in shape and extend towards the second end 10 of the support member 6, such that spaces 12 are formed between a rear part of the flanges 4 and the support member 6. Each of a plurality of flanges 4 includes a substantially semicircular cross section A. The flanges 4 have varying sizes, such that the cross section A of the flange adjacent to the first end 8 of the support member 6 is the smallest, with each successive flange 4 having a larger cross section A.

The support member 6 further includes a channel 14 formed through it, along a longitudinal axis of the ear protector 2. That is, the channel 14 extends through the support member 6 from the first end 8 to the second end 10. The channel opens outwardly of an ear protector 2 at the first and second ends 8 and 10 of the support member 6. In a preferred embodiment, the channel 14 is substantially cylindrical in shape.

The ear protector 2 further comprises a tube 16 disposed within the ear protector 2 in a channel 14. That is, the tube 16 is attached to the ear protector 2, and, more particularly, to the interior of the support member 6 in the channel. 14. The tube 16 is hollow, with a substantially cylindrical shape, and can be positioned inside the ear protector 2 to extend from, be flush with, and / or be recessed at each of the first and second ends 8 and 10 of the support member 6. In a preferred embodiment, as shown in figure 2A, the tube 16 includes an end placed approximately flush with the second end 10 of the support member 6 and an opposite end disposed in the middle of the support member 6, adjacent to the largest of the flanges 4.

The earplug 2 is generally composed of a resilient polymeric material and can be formed by any suitable conventional manufacturing techniques, preferably including injection molding. The resilient polymeric material has a hardness value, measured by a Shore A durometer, sufficient to provide flanges 4 with a desirable degree of elasticity. The support member 6 can be formed from the material in order to have a hardness value, thereby providing a degree of rigidity for the ear protector 2.

There are several known resilient polymeric materials that can be used effectively in the manufacture of earplugs 2, including, but not limited to, natural rubber, neoprene rubber, SBR rubber, silicone rubber, EPDM rubber, polybutadiene rubber , polyurethane elastomers, vinyl halide polymers, etc.

Tube 16 can be composed of any suitable material, 5 providing tube 16 with the necessary elasticity, semi-rigidity, or rigidity. For example, the tube can be produced from a polyether ether ketone (PEEK), a metal, a synthetic or natural rubber material, or a plastic material such as polyethylene, PVC, nylon, vinyl, etc., or combinations thereof .

The tube 16 is fixed to the inside of the support member 6 through the channel 14, preferably by a friction fit. As mentioned, both channel 14 and tube 16 are substantially cylindrical in shape. Tube 16 includes an outer diameter D_AND and an internal diameter D |. The outer diameter D_and of tube 16 and the diameter of tube 16 measured from its outer surfaces, that is, the surfaces of tube 16 that are in contact with the ear protector 2. The inner diameter Di of tube 16 is the diameter of the tube measured at from their inner surfaces, that is, the surfaces that do not come into contact with the ear protector 2. To provide the desired friction fit to the tube 16 within the channel 14, the outer diameter D_AND of tube 16 is dimensioned slightly larger than the diameter of channel 14. Thus, when tube 16 is inserted in channel 14, the resilient polymeric material that makes up the portion of the support member 6 adjacent to channel 14 is slightly displaced, causing a compaction / tension situation in it, which creates the desired friction fit between the ear protector 2 and the tube 16.

Alternatively, the tube 16 can be attached to the ear protector 2 via channel 14, by a bonding agent. For example, a glue can be applied to tube 16 and / or channel 14 before insertion of the first into the second. Then, after the glue has cured, the tube 16 is firmly attached to the resilient polymeric material of the earplug 2.

As mentioned, earplug 2 is made of any suitable resilient polymeric material. Earplugs 2 and / or parts thereof can be produced by any suitable process, including, but not limited to, injection molding, casting, extrusion, etc.

The ear protector 2 also includes a filter 18 disposed inside the channel 14. In this example embodiment, the filter 18 is disposed inside the channel, at one end of the tube 16. As shown in figures 2A and 2B, the filter 18 is disposed on and around an end of the tube 16 located in the channel 14, inside the support member 6. Here, the filter 18 is a flexible porous membrane that surrounds and covers the inside of the end of the tube

16. In this illustrative example, filter 18 is a mesh filter, preferably a polyester, which is approximately 400 to 500 threads per 2.54 cm (1 inch). The mesh that forms the filter 18 includes openings, with each having an area in cross section of about 2.6E-6 cm² (4 x 10 '⁷ square inches) to about 3.9E-6 cm² (6 x10 '⁷ square inches) and preferably about 3.2E-6 cm² (4.9 χ 10 '⁷ square inches).

The filter 18 is preferably attached to the tube 16 and secured within the channel 14 by a friction fit. Particularly, before the insertion of the tube 14 into the channel 16, as discussed generically above, the mesh filter is disposed at one end of the tube 16 and partially encased in it. See figure 2C. This end of the tube 16, with the mesh filter 18 in it, is pressed against the opening of the channel 14, at the second end 10 of the support member 6 of the ear protector 2. As the tube 16 is pushed into the support member 6, the inner end of it and the mesh filter 18 disposed on it pass through the channel, until the position shown in figure 2A is reached. As the tube 16 is pushed into the channel 14, the mesh filter 18 is forced firmly over the open end of the tube 16. The edges 19 of the filter 18 that extend beyond the outer diameter De of the tube 16 are pressed between the tube 16 and the walls of the support member 6 that delimit the channel 14. This creates a narrow friction fit of the filter 18 at the inner end of tube 16, thus holding filter 18 within channel 14. Most importantly, all edges 19 of filter 18 extend beyond the outside diameter D_AND of the tube 16, in such a way that there are no openings between the filter 18 and the inner diameter D |, through which sound can pass without impediment. That is, the filter 18 is attached to the tube 16 inside the channel 14 in such a way that, when the ear protector 2 is inserted in a user's ear canal, all the sound that passes through the tube 16 and the channel 14 must also pass through filter 18.

In the present example, the 18 mesh filter is substantially square, having a length and width of about 0.64 cm (0.25 inches). Obviously, this is simply illustrative. Filter 18 can be of any shape that has a dimension in one direction of about 0.48 cm (3/16 inches), and that has a dimension in another substantially orthogonal direction of about 0.31 cm (5/16 inches). More generally, the filter 18 comprises a size and shape sufficient to fully cover the inner end of the tube 16 and extend at least partially along the outer sides of the tube 16, such that the tube 16 and the filter 18 may be arranged within channel 14, as discussed in the following paragraph. That is, the filter 18 can be square, rectangular, circular, oval, etc., or have any combination of them, having the dimensions described.

In use, the second end 10 of the support member 6 acts as a cable that is picked up by the user during insertion. Earplug 2 is placed close to the user's ear and then inserted into the ear canal. The first end 8 of the support member 6, and the smallest of the flanges 4 arranged therein, enter the ear canal first, during insertion. Then, the earplug 2 is pushed into the channel by a second end 10 of the support member 6. The flanges 4 slightly compressed during insertion are housed in the ear canal to significantly block the passage of sound. A portion of the second end 10 of the support member 6 remains in the opening of the ear canal or extends slightly out of it, acting as a cable to remove the ear protector 2.

The tube 16, as arranged in the support member 6, in combination with the channel 14, forms a route through the ear protector 2 such that, when the ear protector 2 is properly inserted as described, a narrow column of air is created between the user's inner ear and the external environment. This air column essentially comprises a crack in the occlusion provided by the ear protector and thus allows the sound to penetrate the ear protector and reach the auditory organs in the user's inner ear. In this way, a reduced attenuation is provided by the ear protector, in such a way that, when properly inserted, the user hears sounds from the external environment, but is still endowed with a degree of hearing protection.

The air column created by the channel 14 and the tube 16 is interrupted by the filter 18 which extends along the inner end of the tube 16. The air column is essentially an intentional slit formed in the ear protector 2 to allow sound pass through ear protector 2 to a user's inner ear. This crack reduces the overall degree of sound attenuation provided by the earplug 2. However, the openings of the filter 18 form areas of airflow resistance that serve to attenuate or reduce the amplitude of a sound wave that passes through the tube 16, thereby providing attenuation of some or all of the drained sounds. In this way, the filter 18 maintains the reduced attenuation provided by channel 14 and tube 16, especially when the ear protector 2 is subjected to low frequencies. For example, a test of the earplug 2 indicated an SNR of 14, when tested according to the EN352-2 standard.

The sound transmission through the route created by the tube 16 depends, among other things, on the volume of the air column formed inside the tube 16 and the porosity of the filter 18 that covers the inner end of the tube 16. That is, at least the inner diameter D | and the length of the tube 16 (which delimit the internal air column), and the opening size and density (that is, opening per square inch) of the filter, are critical parameters for the transmission of sound through the ear protector 2.

Generally, the tube 16 can have any external diameter De of sufficient size, in order to be readily inserted into the channel 14, and in order to be attached to it by a sufficient friction fitting, as discussed above. The inner diameter D | of tube 16 is chosen to facilitate a desired sound propagation. For example, the inner diameter Di is generally in the range of approximately 0.08 cm (0.031 inches) to approximately 0.16 cm (0.062 inches). The corresponding length X of tube 16 is approximately 0.51 cm (0.200 inches) to approximately 1.27 cm (0.500 inches), respectively. More particularly, in a preferred embodiment, the inner diameter D 1 is approximately 0.076 cm (0.030 inches) and the length X is approximately 0.65 cm (0.256 inches). In another embodiment, the inner diameter Di is approximately 0.05 cm (0.020 inches) and the length X is approximately 1.27 cm (0.500 inches). As mentioned, the 18 mesh filter is approximately 0.64 cm (0.25 inches) by 0.64 cm (0.25 inches), and includes openings with an area of ​​about 2.6E-6 cm² (4 x

10'⁷in²) at about 3.9E-6 cm² (6 x 10 '⁷in²). The openings are evenly distributed along the fabric filter 18 at a density of about 460 openings per 6.5 cm² (1 square inch).

An important feature of ear protector 2 is that the edges 19 of the filter 18 extend over and beyond the outer diameter limits D_AND tube 16 in order to wrap or cover the open inner end of tube 16. That is, no open space is provided between the filter 18 and the inner diameter D | tube 16, through which the sound can propagate unimpeded through tube 16 and, finally, to the user's inner ear. This arrangement provides low attenuation, but even greater than zero attenuation, even at the lowest frequencies. For example, earplug 2 can provide an SNR value of about 12 to about 17 when tested according to the EN 352-2 standard.

The compression or other deformation of the tube 16 during, for example, the insertion of the ear protector 2 in the user's ear canal is clearly undesirable, due to the fact that this deformation of the tube 16 would result in the corresponding deformation of the air column delimited by the same . Thus, the material (s) used to manufacture the tube 16 (see above) must be suitable to maintain the shape and dimensions of the tube during the use and common handling of the ear 2. For example, tube 16 can be manufactured from a rigid or semi-rigid rubber or plastic material.

Additionally, the tube 16 in this embodiment is placed in the channel 14 near the second end 10 of the support member 6, as shown through the example in figure 2A. This feature provides several advantages, including the arrangement of the tube 16, in order to limit the compression forces exerted on it when the ear protector 2 is inserted into the ear canal. That is, during insertion, the flanges 4 are received inside the ear canal and the second end 10 of the support 6 is positioned in the opening of the ear canal or extends from it. Thus, the flanges 4, and not the second end 10 of the support member 6, receive most of the compression forces associated with the insertion of the ear protector 2.

In addition, a comfort advantage is derived from the arrangement of the tube 16 close to the second end 10 of the support member 6. In particular, the rigid or semi-rigid nature of the tube 16 does not affect a user when wearing the earplug 2 because, as mentioned above, the second end 10 of the support member is not generally within the ear canal when the earplug 2 is inserted. In this way, the user is exposed only to the comfortable and malleable nature of the first end 8 of the support member 6.

The portion of the channel 14 that is not supported by the tube 16 can be reinforced, as discussed in this document, to contain the compression forces of the insert. Alternatively, such a channel may not include a reinforcement and, thus, it may compress slightly during insertion and / or use. However, the invention contemplates such conditioning and, thus, dimension channel 14 appropriately in such a way that the compression of channel 14 does not inhibit the desired passage of sound. That is, the sound path or the 'crack' is maintained even during the compacting of the channel 14, due to the adequate dimensioning of the channel diameter.

So far, tube 16 has been described illustratively as extending generally from the second rear end 10 of the support member 6 to generically the middle of the support member 6 near the widest flange 4. See figure 2A. However, tube 16 can be of any desired length and can be arranged in any desired position within channel 14. For example, as shown in figure 2D, tube 16 has a length X 'significantly less than that shown in figure 2A. Here, the tube 16 is disposed within the channel 14 in a position within the support member 6, away from the second end 10. The filter 18 is fitted to the end of the tube 16 closest to the first end 8 of the support member 6, as discussed above in relation to the configuration in figure 2A.

So far, the invention has been described including tube 16 and filter 18 chafed within channel 14. However, the invention clearly contemplates other modalities where, for example, there is no such tube 16. That is, in an alternative modality, ear protector 2 includes channel 14, which has the appropriate internal dimensions to form the desired air column that extends through ear protector 2. In such an embodiment, the filter is arranged inside the support member 6 in order to extend completely along the channel 14. For example, the filter can be connected to the support member 6 in the channel 14, such that the filter 18 it extends completely along the channel 14. Alternatively, the filter 18 can be integrally formed with the support member 6.

The earplug 2, as shown and described here, may also include a stem (not shown) embedded in and / or extending from the support member 6. The stem can be used: to provide a degree of rigidity to the support member, such as a cable to facilitate the insertion and removal of the ear protector 2 from the user's ear canal, to connect a cord or other device to the ear protector, etc. The stem is arranged along the longitudinal axis of the earplug 2. In this way, the channel 14 extends through portions of the support member and through at least a portion of the stem. Such rod is composed of a rigid or semi-rigid material, such as synthetic or natural rubber, plastic, etc.

Figures 4 and 5 show an ear protector 20, according to another embodiment of the invention. It should be noted that similar parts and components are indicated here and throughout the document using compatible reference numbers.

The earplug 20 includes a sound attenuating portion 22 disposed at the first end 8 of the elongated support member 6. Sound attenuating portion 22 is generally any item that is insertable into a user's ear canal, and suitable for blocking and / or cushion what passes through the ear canal. More specifically, as shown in figures 4 and 5, the sound attenuating portion 22 is a substantially hemispherical shoulder which extends posteriorly towards the second end 10 of the support member 6.

The ear protector 20 also includes the channel 14 which extends along a longitudinal axis of the ear protector 20, through the support member 6 and through the sound attenuator element 22, such that the channel opens to the external environment on an insertion surface 24 of the sound attenuator element 22 and on a second end 10 of the support member

6. The tube 16 is disposed inside the ear protector 20 in the channel 14, being maintained in it, preferably, by a friction fitting that results from the fact that the outer diameter D_AND of tube 16 is slightly larger than the diameter of channel 14. Tube 16 may extend to the exact length of channel 14, or it may have a length X less than or greater than the length of channel 14. In a preferred embodiment, as shown in figure 5, tube 16 is substantially shorter than the channel and is disposed near the second end 10 of the support member 6. The filter 18 is disposed on the inner end of the tube 16 and extends completely along the inner and outer diameters Di and D_AND, and involves sides of the tube 16, in order to be coined between the tube 16 and the material of the support member 6 that forms the channel 14. The arrangement, aspects and characteristics of the filter 18 in relation to the ear protector 20 are similar to those discussed above, in relation to the ear protector 2.

The support member 6, as mentioned above, is produced from any suitable malleable, semi-rigid, or rigid material, as desired. In particular, the support member 6 can be composed of a plastic or a rubber material, and can preferably be formed through injection molding.

The sound attenuating portion 22 is preferably made from a compressible resilient material, such as, for example, a compressible resilient plastic, or a rubber material or composition. Preferably, the sound attenuating portion is composed of a foam-like material, composed of a soft, malleable and self-molding foam, with instant recovery properties, such as a polyurethane or an acrylic blend foam. Other suitable foams include PVC, silicone and nitrile, among others. A suitable foam is described, for example, in US Patent No. 5,792,998, issued to Gardner, Jr. et al., Incorporated herein by reference. The earplug described here comprises a dynamically rigid foam material, which has a low static stiffness and a high dynamic stiffness. Another suitable foam is described, for example, in US Patent No. 4,158,087, granted to Wood, incorporated herein by reference. The sound attenuating portion 22 can be formed, for example, by a molding process and then attached to the first end 8 of the support member 6 by a bonding agent, such as a glue.

In use, the earplug 20 is handled from the second end 10 of the support member 6, and placed close to the user's ear. Then, the sound attenuator element 22 is inserted into the opening of the ear canal and inserted into the channel by pushing the second end 10 of the support member 6. Sound attenuator element 22 is compressed into the ear canal and blocks it, to attenuate the passage of sounds from the external environment to the inner ear. The second end 10 of the support member 6 remains in or extends from the ear canal, when the ear guard 22 is fully inserted. To remove the earplug 20, the user grips the second exposed end 10 and pulls the earplug 20 out of the ear canal.

As mentioned, the compressed sound attenuating portion embedded in the ear canal provides attenuation, however, sound is allowed to reach the inner ear through the air column formed and maintained by channel 14 and tube 16, extending through the ear protector 20.

Here again, as described above with reference to the 5 figures 1, 2 and 2A, the inner diameter D | tube 16 is approximately 0.08 cm (0.031 inches) to approximately 0.16 cm (0.062 inches), length X is approximately 0.51 cm (0.200 inches) to approximately 1.27 cm (0.500 inches), and, more particularly, in an exemplary embodiment, the inner diameter D | is approximately 0.10 cm (0.040 inches) and length X is approximately 0.65 cm (0.256 inches), and in another modality, the D | is approximately 0.05 cm (0.020 inches) and L is approximately 1.27 (0.500 inches).

The filter 18 of the earplug 20 includes openings, as discussed above, which creates areas of airflow resistance that attenuate or reduce the amplitude of a sound wave that propagates through the tube 16, as discussed in relation to the earplug. ear 2, causing ear protector 20 to have a reduced sound attenuation, greater than zero, over a range of frequencies, including lower frequencies.

Additionally, while the ear protector 20 that has been described so far includes the tube 16, the invention contemplates a modality of the ear protector 20 without the tube 16, where the filter 18 is arranged and / or fixed within the channel 14, as discussed above with reference to the earplug 2.

Figures 6 and 7 show an ear protector 50 in another embodiment of the invention. The earplug 50 includes a structural part 52 that has a first end 54 and an opposite second end 56.

Additionally, the ear protector 50 includes the channel 14 formed along a longitudinal axis thereof, from the first end 54 to the second end 56. The tube 16 is disposed within the channel and the structural part 52 is fixed therethrough. The filter 18 is disposed at the inner end of the tube 16 and extends completely along the inner and outer diameters Di and De, and surrounds sides of the tube 16, in order to be coined between the tube 16 and the material of the structural part 52 that delimits channel 14. The layout, aspects and characteristics of the filter 18, in relation to the ear protector 20, are similar to those discussed above, in relation to the ear protector 2. The tube 16 and the filter 18, as described above, are preferably chained together in channel 14, but can also be adhered or connected.

The earplug 50 is formed of a compressible resilient material 10, such as, for example, a foam-like material. More particularly, the earmuff 50 is preferably composed of a foam produced from a polyurethane, an acrylic blend, a PVC, a silicone, a nitrile, etc. The earplug 50 can be formed by any suitable conventional manufacturing process, including, but not limited to, molding, extrusion, die casting, etc.

Channel 14 can be formed at the time of manufacture of structural part 52 or at a subsequent processing step. For example, where structural part 52 is formed by molding, a relevant mold includes an insertion element arranged around it in order to form the channel

14 in structural part 52. That is, the foam material, in a liquid form, is injected into the mold. The insertion element is, for example, a pin-shaped element that extends within the molded cavity. The foam material is left to expand and fill the mold around the insert. Once the foam is fully formed, a new structural part 52 is ejected from the mold. During ejection, the insertion element is removed from the structural part, thus resulting in the formation of the canal 14.

Of course, alternatively, channel 14 can be made in a separate processing step. That is, structural part 52 can be manufactured first and then the channel can be formed subsequently by, for example, drilling, roughing, laser treatment, as described in US patent application No. 10 / 346,604, granted to Taylor , here incorporated by reference, in its entirety, water jet treatment, as described in US patent application No. 10 / 660,015, granted to Schreiber, hereby incorporated by reference in its entirety, and etc.

After the formation of the structural part 52 and the channel 14, the tube 16 with the filter 18 is then inserted in the channel 14 and fixed to the structural part 52 in a similar way to that discussed in relation to the ear protector 2. The tube

16 can be longer or shorter than a channel length

14. In the illustrated embodiment, the length of the tube 16 is substantially less than the length of the channel 14, and is disposed close to the second end 56 of the ear protector 50.

In use, the earplug 50 is first compressed to reduce a cross-sectional diameter thereof. This is preferably achieved when the user rotates the earplug 52 between fingers or hands, around the longitudinal axis of the protector. This scrolling / compression technique is applied until the diameter of the earplug 50 is approximately less than the diameter of the user's ear canal. Then, the first or second end 54 and 56 of ear protector 50 is inserted through the opening of the ear canal and into the channel. The ear muff 50 is inserted into the ear canal at such a depth that the end end 54 and 56 of the structural part 52 is at or extends slightly from the opening of the ear canal. Once inserted into the ear canal, the resilient material that makes up the ear muff 50 expands from its temporarily compressed state to better fill the ear canal and fit the ear muff 50 into it, effectively attenuating the sound passage.

However, while a significant degree of sound attenuation is achieved by the structural part 52 of the ear protector 50, the channel 14 and the tube 16 that extend through the nucleus of the structural part 52 delimit an air column that connects the auditory organs of the ear internal to the external environment. In this way, the sound from the external environment is allowed to pass through the tube 16 to the inner ear. In this way, the ear protector 50 provides the user with a degree of hearing protection while still allowing sound to be heard, thereby providing relatively reduced attenuation. The filter 18 is disposed inside the ear protector 50, in such a way that part of the sound that propagates through the tube 16 passes through the openings of the filter 18.

As mentioned earlier, the openings of the filter 18 delimit areas of airflow resistance, which attenuate the sound that passes through the tube 16. The inner diameter D1 of the tube 16 of the earplug 50 is as previously described. The configuration of the earplug 60 results in less attenuation (but less than zero attenuation) over a frequency range, including especially low frequencies.

According to other modalities of the invention discussed here, the ear protector 50 that has been described so far includes the tube 16. However, the invention clearly contemplates an ear protector 50 that does not include a tube 16. Such modality of the ear protector 50 it would include channel 14, as described, but would be formed to have the particular dimensions discussed above, in relation to tube 16, to delimit the air column, as desired. In such an embodiment, the filter 18 would be arranged and / or fixed within the structural part 52 of the ear protector 50, in channel 14, and would extend along it, in order to filter the sound that propagates through channel 14 , as discussed in detail above.

In addition, the ear protector 50 shown in figures 6 and 7 has a tube 16 disposed in channel 14, with one end which is contiguous with the second end 56 of structural part 52, and with the other end of tube 16 extending to approximately the middle of structural part 52. This, of course, is an example of configuration. According to previous embodiments, the tube 16 may include a length X shorter than that shown, such that both ends of the tube 16 are arranged in the channel 14, in a central region of the structural part 52 of the ear protector 50.

The hearing protection devices of the invention, which have been described to date, include a single tube 16 disposed in a channel 14 that extends through the hearing protection device, where a single filter 18 is placed on an inner end of the tube 16 This configuration is, of course, merely illustrative. A hearing protection device according to the invention can include a plurality of tubes 16 arranged in channel 14, with each tube being fitted with a filter 18. For example, the earplug 2 of figure 2D may include a plurality of small tube / filter arrangements 16/18, such a plurality being arranged along the length of the channel 14.

Even more alternatively, in another exemplary embodiment of the invention, an ear protector 60 is provided, as shown in figure 8, including a channel 14 that is slightly wider in width than the previous embodiments, in order to receive and retain a second tube 62 within which the first tube 16 is arranged. The filter 18 is arranged as shown to cover and close an inner end of the second tube 62, The first tube 16 can be chained into the second tube 62 or, alternatively, can be connected to the second tube 62, or it can be integrally formed with the same, etc. A first end of the second tube 62 extends to the first end 54 of the earmuff 60. This first end of the second tube 62 is shown in figure 8 extending beyond the first end of the first tube 16. The second ends of the first and second tubes 16 and 62 are equally arranged and generally flush with the second end 56 of the ear muff. 60. This setting is, of course, exemplary, and can be changed. For example, the first tube 16 may be more centered within the structure 52 of the ear protector, such that the second tube 62 extends beyond both the first and second ends of the first tube 16. It is also noted that the distance of the second tube 62 that extends beyond the first tube 16 at the first and / or second ends can vary as desired, and the second tube 62 can be positioned in channel 14, so as not to be in a borderline position with none of the ends 54 and 56 of the structural part 52 of the ear protector.

As per ear protector 50 discussed above, the present ear protector 60 provides a significant degree of sound attenuation, but the first and second tubes 16, 62 extending through the core of structural part 52, in combination with the remaining portion of channel 14, delimit an air column that connects the auditory organs of the inner ear to the external environment, when the ear protector 60 is worn by a user. In this way, the sound from the external environment is allowed to pass through tubes 16 and 62, to the inner ear. Also, as explained earlier in this document, filter 18 attenuates part of the sound that propagates through that column of air. In this way, the ear protector 60 provides the user with a degree of hearing protection, while still allowing sound to be heard, thereby providing low attenuation over a range of frequencies and, especially, low frequencies.

The inner diameter D | of the first tube 16 is as previously described. The inner diameter D | second tube 62 is approximately 0.05 cm (0.020 inches) to approximately 0.23 cm (0.090 inches), length Y is approximately 0.25 cm (0.100 inches) to approximately 3.18 cm (1.250 inches) , and, more particularly, in a preferred embodiment, the inner diameter D 1 is approximately 0.16 cm (0.062 inches) and the length Y is approximately 1.78 cm (0.700 inches). The channel 14 is dimensioned correspondingly, in relation to the first and second tubes 16 and 62.

Figures 9 to 11 show a semi-auricular device 100, 5 in an embodiment of the invention. The semi-auricular device 100 includes a curved neck band 102 having a first end 104 and an opposite second end 106. Sound attenuating elements 108 are arranged at each of the first and second ends 104 and 106 of neck band 102 Neck strap 102 includes a connecting portion

110 arranged on the first and second ends 104 and 106. The sound attenuating elements 108 each include a retaining portion 112 that receives and retains the connecting portion 110 of the neck band 102. The retaining portion 112 is arranged in a distal end 114 of each sound attenuating portion 108. Distal end 114 is located opposite the insertion end 116 of sound attenuating element 108.

In one embodiment, as shown in figure 10, the connecting portion 110 of the neck band 102 is substantially spherical in shape. The retaining portion 112 of the sound attenuator element 108 is correspondingly hollow spherical in shape. Consequently, the combination of the connecting portion 110 and the retaining portion 112 effectively forms a ball and socket connection that securely attaches the sound attenuator element 108 to the neck band 102, but allows the attenuation element 108 to rotate around the same.

In the embodiment shown in figure 10, the sound attenuator element 108 also includes channel 14, tube 16 attached to it, and filter 18 arranged over and covering the inner end of tube 16. Channel 14 can take any course from the insertion end 116 of the sound attenuating element to the distal end 114, and it is shown in an exemplary way that it linearly traverses element 108, from an angle to a longitudinal axis of element 108.

In another embodiment of the semi-auricular device 100, as shown in figure 11, the connecting portion 110 is similar to a rod and is received and retained in a fixed manner within the correspondingly shaped retaining portion 112. Here, the connecting portion 110 is fixed within the retaining portion 112 by friction fitting, a binding agent, etc. In this way, the sound attenuator element 108 is held rigidly in the neck band 102. The sound attenuator element 108 of this present embodiment also includes channel 14, tube 16 attached to it, and filter 18 arranged over and covering the inner end of tube 16. Here, channel 14 extends linearly along a longitudinal axis of the sound attenuator element 108, from the insertion end 116 to the distal end 114, and through the retaining portion 112, connecting portion 110, and through the end 106 of the neck band 102.

Preferably, the sound attenuating elements 108 are formed of a compressible resilient material, such as rubber, plastic, or foam-like material. Neck band 102 is composed of one or more materials of rigid rubber or plastic. The tube 16, as previously described, is composed of a rigid or semi-rigid material, such as rubber or plastic, to maintain its integrity during the handling and use of the semi-auricular device 100. The tube 16 can extend through the entire set described, or only through a portion or the entire sound attenuator element 108, as desired. Preferably, as shown in figures 9 and 10, the tube 16 extends only partially in channel 14, and is disposed near the distal end 114 of the sound attenuator element 108. The filter 18 is, for example, a mesh square that has openings formed through it, the mesh square substantially surrounding and covering the inner end of the tube 16, as discussed above in relation to the exemplary embodiments of the invention.

In use, the insertion ends 116 of the sound attenuation elements 108 are placed close to the opening of a user's ear canal. The insertion ends 116 pass through the opening of the ear canal and the sound attenuating elements 108 are pushed correspondingly into the ear canal, which are compressed and fitted in place, effectively attenuating the sound. When the sound attenuator elements 108 are properly inserted, as described, the neck band 102 falls behind the chin or along the back of the neck, or is placed over the user's head to support the semi-ear device 100 and to facilitate its handling.

The tube 16 extending through channel 14 of the sound attenuating elements 108 forms the air column previously discussed, connecting the user's inner ear to the external environment, to allow sound to be heard by the user. In this way, the semi-auricular device 100 provides attenuation to the user but still allows sound to be heard, resulting in a low attenuation ear protector. Filter 18, as discussed above, absorbs or dampens sound, particularly low frequency sounds, which propagate through tube 16. The result is a semi-auricular device 100 that provides low (but even greater than zero) sound attenuation ) over a range of frequencies, including lower frequencies.

The semi-auricular device 100 described herein includes tube 16.

However, as discussed in relation to other embodiments of the invention, the semi-auricular device may not include tube 16, and may simply include channel 14, provided and sized appropriately to form the air column through the sound attenuating elements for the propagation of sounds. It is clear that, in such an embodiment, the filter 18 which would be either fixed to the sound attenuator element 108 in channel 14, or to filter 18, would be in a self-supported friction fit within channel 14.

While channel 14 and tube 16 have been shown and discussed 5 here and throughout the document as having a generally cylindrical shape and traversing a straight path (for example, a longitudinal axis of the earplug, as shown in figures 2A , 5, 7 and 11), the invention clearly contemplates the tube 16 and / or the channel 14 as having any shape and crossing any sufficient and adequate path to create a path for the transmission of sound from the external environment to the auditory organs of a user's inner ear. For example, tube 16 and / or channel 14 can have any desired straight and / or curvilinear cross section and, in addition, can cross a desired path through a particular hearing protection device (for example, in a straight line, in angle, curve, helical, etc.). Additionally, the tube 16 and / or the channel 14 can have varying widths in cross section along its length.

The earmuffs shown and described here and throughout the document may also include a stem and / or a cord extending from it. The stem and / or cord can be attached to a surface of the earmuff by a bonding agent, or the stem and / or cord can be partially embedded in the earmuff and then attached to it. Tube 16 and / or channel 14 can extend through a portion of the rod and / or cord, to complete the formation of the air column necessary to transmit the sound to the user's inner ear. In this case, the filter 18 would be disposed within the rod or cord. Alternatively, tube 16 and / or channel 14 may diverge from the connection point of the rod and / or cord, and exit at one end of the earmount opposite the insertion end.

The hearing protection device of the invention features a device, particularly an ear protector, which provides the user with a relatively low (but greater than zero) sound attenuation over a frequency range and, especially, at lower frequencies. The hearing protection device is a simple construction, and needs only a cheap pipe and filter. In addition, the ear protector of the invention is easy to manufacture, cost effective, and durable.

While the invention has been described with reference to an exemplary embodiment, those skilled in the art will understand that various changes can be made and equivalents can serve as substitutes for elements thereof, without departing from the scope of the invention. In addition, several modifications can be made to adapt a particular situation or material to the teachings of the invention, without departing from its essential scope. Therefore, this means that the invention is not limited to the particular modality presented as the best method contemplated for carrying out this invention, but that the invention will include all modalities that fall within the scope of the appended claims.