Abstract:
An ear tip made partially of a secondary insert, clamp, sleeve band or other memory retaining elastic material that, when integrated with a biocompatible, soft, highly elastic and vibration and sound damping material provides improved containment and isolation of sound pressure within a sound transmission path and provides the necessary retention for this type of acoustically superior material to be retained properly on a sound generating assembly.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/130,190 filed Mar. 9, 2015, the entirety of which is hereby incorporated by reference as if fully set forth herein. 
     
    
     FIELD 
       [0002]    The subject invention pertains generally to ear tips for sound devices and specifically to ear tips using superior acousto-mechanical damping and comfort assisting materials. 
       BACKGROUND 
       [0003]    Soft ear inserts are part of sound devices which are often worn for significant periods of time during the day. Today, these devices include hearing aids, personal sound amplifiers (PSAP&#39;s), Bluetooth Headsets and Audio Headsets, to name a few. These soft ear inserts and associated devices are referred to herein as “ear tips.” For these products, early technology used soft urethanes and foams which often discolored or quickly dirtied needing frequent replacement and were rigid enough to cause significant ear discomfort over extended periods of daily usage. The industry has since moved to mostly silicone ear tips which provide a softer material for increased comfort and biocompatibility. Silicone ear tips have also the additional advantage of mechanical elasticity memory. That is, they maintain their grasping force once mounted onto the sound port nozzle. 
         [0004]    Silicone based ear tips or ear inserts, widely used today, are biocompatible and can be adjusted to the proper level of softness for the desired comfort. Ear tips used by devices without ear level microphones such as headphones, provide comfort and isolation of the ear canal from ambient sounds. Many times the ambient sounds are not sufficiently attenuated inside the ear canal which can be caused by the ambient sound pressure vibrating the ear insert and deforming the surfaces of the ear insert exposed to and in direct response to the air pressure modulation of said ambient sound field. This deformation propagates through the body of the ear insert which in turn causes deformation of the ear insert on its other surfaces which face the occluded ear canal space. This causes a related sound pressure to be developed inside the ear canal cavity. This effect is especially apparent if the insert is made of thin silicone. The action of the surfaces is similar to the walls of a balloon expanding and contracting in response to changes of the air pressure within. This effect represents the conversion of acoustic energy to mechanical vibrational energy and back to acoustic energy. This unintentional and undesired acoustic to mechanical and back to acoustic (acousto-mechanical) sound coupling is referred to herein as the “ballooning effect.” In order to increase the acoustic seal and reduce vibration and the “ballooning effect” of the ear insert and thus increase the attenuation of external ambient sound, the ear inserts need to be made of thicker or harder silicone thus compromising comfort. 
         [0005]    For devices that provide high amplification and have ear level microphones, the ear insert should also provide sufficient sound seal as to limit “sound leakage” from inside the ear canal cavity to outside where the microphone is in order to avoid well known feedback. A sound containing or transmission body such as an ear tip or ear insert or a sound tube consists of a body made of a deformable solid material and having first surfaces (or first walls) in contact with a first air path which in turn contains an intended sound pressure (said first air path also referred to as a sound containing or sound transmission path). Second surfaces (or second walls) of the sound containing body may be in contact with other air paths or with free air but are distinguished from first surfaces as not being in direct contact with said first air path. “Sound leakage” is not necessarily due to the obvious failure of an incomplete air-tight seal to close off an unintentional air path or leak from the first air path but also through the same non-obvious mechanism referred to above as the “ballooning effect” wherein said intended sound pressure contained within the first air path expands and contracts the first surfaces or first walls and wherein the expansion and contraction of said first walls or first surfaces causes related deformation of second surfaces or walls which then in turn re-radiates an unacceptable portion of the intended sound pressure as a corresponding unintended sound pressure into said other air paths or to free air. Thus the leakage could be in the form of direct sound pressure leakage due to insufficient air-tight seal or in the form of sound pressure generated by the vibration of the soft walls of ear insert due to the “ballooning effect” from sound pressure delivered to the ear canal enclosed by the ear tip. 
         [0006]    Newer, highly elastic yet vibration and sound damping materials have now become available which when used to manufacture an ear tip improve comfort during prolonged headset ear tip usage as well as significantly decrease said “ballooning effect” both to and from the human ear canal. These materials do so by converting less of the mechanical energy imparted by the contained acoustic pressure into expansion and contraction of the walls, while more of said mechanical energy is dissipated as heat within the material due to its internal damping characteristics. Note that damping used to ameliorate the “ballooning effect” should in no way be confused with any unrelated damping of the air path used as a sound passage by placing acoustic resistances in the air path. Any further references to sound damping herein specifically refer to internal vibrational damping of the material making up the walls or surfaces of said sound containing or sound transmission body for containing, isolating or delivering a sound pressure rather than damping the air path of a sound transmission body. The drawback to these types of highly elastic and sound vibration damping materials is that they are so soft and elastic that when they are mounted onto a sound port nozzle of an amplification device they do not have robust mechanical retention. These materials have low elasticity memory and when installed onto a device they often stretch, expand, and remain in this steady state expanded condition. In this condition, the materials by themselves do not provide enough residual retention to remain on the nozzle when being removed from the human ear. This inadequate retention results in the ear insert falling off or remaining stuck in a human ear leaving the user to attempt to remove it, or worse, make a trip to an emergency room or doctor to remove the ear tip. These situations range from a major annoyance to the consumer to more dangerous medical outcomes and increased liability for companies selling these devices. 
         [0007]    Low retention forces of ear inserts to amplification devices/headsets (usually those lower than 200-300 grams) often have outcomes of an eventual failure of an ear insert to remain mounted onto a headset. Although this retention force number is dependent on many variables including the base materials of the headset and ear tips, ear wax, body oils, cleanliness of the interface, and geometries of the ear tip, the mating portion of the headset and the human ear canal being entered, the fact remains, at these low forces, potential ear tip mechanical retention failures can and do occur. Higher retention forces of ear tips to headsets (usually those over 1000 g) provide a reliable mechanical retention of the ear tip to the headset supporting any combination of variables described above as well as keeping the force low enough for a user to easily assemble an ear tip on their headset. 
         [0008]    It is not intended to specifically define herein all current and future materials that fall into the category described as “highly elastic, sound and vibration damping” materials which reduce the “ballooning effect”. One such material available today is Qflex made by Flexan Corp. Silicone, by contrast, has far less vibration and sound damping capability. 
         [0009]    In view of the foregoing, there is a need for an alternative means for creating mechanical retention to allow technically superior, highly elastic, sound and vibration dampening acoustic ear tip materials to maintain proper retention on associated headset devices. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1A  is a perspective view of an ear tip according to embodiments set forth herein with the ear tip in an inverted state. 
           [0011]      FIG. 1B  is a front elevation view of the ear tip represented in  FIG. 1A . 
           [0012]      FIG. 1C  is a cross-sectional side view of the ear tip represented in  FIG. 1A . 
           [0013]      FIG. 2A  is a perspective view of an ear tip according to embodiments set forth herein with the ear tip in its non-inverted, normal state. 
           [0014]      FIG. 2B  is a cross-sectional side view of the ear tip represented in  FIG. 2A . 
           [0015]      FIG. 3A  is a side elevation view of a sound generating device having a sound nozzle for attachment to an ear tip according to embodiments set forth herein. 
           [0016]      FIG. 3B  is a side elevation view of the sound generating device represented in  FIG. 3A  with an ear tip according to embodiments set forth herein attached to the sound nozzle. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
         [0018]    As presented herein, embodiments of the subject invention are directed to an ear tip having at least one section made of a soft, vibration and sound damping material and at least one section made of a memory retaining, higher retention force material. In use, the memory retaining, higher retention force material can be provided as an insert to the soft, vibration and sound damping material section, or can be provided on the outside of the soft, vibration and sound damping material section. 
         [0019]    A suitable high retention force material can be chemically or mechanically integrated to the ear tip to allow for improved retention to a sound generating device. For example, a memory retaining elastic material, like silicone or urethane, may be chemically/mechanically added to the molding of the highly elastic, vibration and sound damping material through any number of processes (compression molding, transfer molding, injection molding, bonding, etc.) which would allow the retention feature of the ear tip to provide increased retention to the ear tip while the headset-human interface of the ear tip retains its superior acoustic, comfort, and vibration and sound damping properties. 
         [0020]    In accordance with one embodiment of the present invention, one or more segments of the ear tip are made of the described soft, vibration and sound damping material and another segment is an insert of memory retaining, higher retention force material which provides reliable retention force during use and prevents the ear tip from becoming lodged in the user&#39;s ear or falling off the headset device during removal from the ear. 
         [0021]    In accordance with another embodiment of the present invention, the memory retaining, higher retention force material is provided on the outer diameter (OD) of the ear tip construction which would provide a similar force on the headset and maintain the retention needed during usage. 
         [0022]    In accordance with yet another embodiment of the present invention, memory retaining, higher retention force elastic materials in the form of non-bonded sleeves, clamps or bands can be assembled to the soft, vibration and sound damping material that provide reliable retention force during use, thereby preventing the ear tip from becoming lodged in the users&#39; ear or falling off the headset device during removal from the ear. 
         [0023]    With reference now to the figures,  FIGS. 1A, 1B, and 1C  illustrate a three dimensional representation of an ear tip  100  with the ear tip  100  in an inverted state. As shown, Ear tip  100  can have ear tip segments  110  and  120  made of a soft, vibration and sound damping material. Ear tip segments  110  and  120  can be integrally joined. Ear tip segment  110  can be an elongated, hollow tube and can taper toward its end where it joins ear tip segment  120 . Ear tip segment  120  can be designed to fit comfortably in a user&#39;s ear canal, thereby holding the ear tip in place during use. Ear tip segment  120  can be an ear dome. Such ear domes are shaped and fitted to fit securely within the concha portion and outer canal portion of a wearer&#39;s ear.  FIGS. 1A, 1B, and 1C  illustrate such an ear dome with the elastic of the dome inverted from its normal operating state. Ear tip  100  can have retaining segment  130  of memory retaining, higher retention force material. Retaining segment  130  take the form of a hollow, cylindrical insert which can be placed inside the internal diameter of ear tip segment  110  in order to attach the ear tip  100  to a sound nozzle. Ear tip segment  100  can provide a sound path  140  for sound traveling from a sound device to a user&#39;s ear canal. Sound path  140  can be a central channel passing through ear tip segments  110  and  120  and retaining segment  130 . 
         [0024]      FIGS. 2A and 2B  illustrate a three dimensional representation of ear tip  100  with the ear tip  100  in its normal, non-inverted state.  FIGS. 2 a    and  2 B illustrate ear segment  120  in the form of an ear dome with the elastic of the dome in its normal operating state. 
         [0025]      FIG. 3A  illustrates a representative sound generating device  300  having a sound nozzle  310  for attachment to an ear tip according to embodiments presented herein. 
         [0026]      FIG. 3B  shows the sound generating device  300  with the ear tip  200 , as shown in  FIG. 2 , attached. The memory retaining, higher force material insert segment of ear tip  200  can mount the ear tip to the sound nozzle of sound generating device  300 . 
         [0027]    The insert as described in  FIGS. 1 and 2  can be comprised of memory retaining material fabricated by any means (most usually some form of molding) and may be an independent item prior to fabrication of the ear tip itself. Once fabricated, this insert can be installed into an ear tip tool (either manually or through automated processes) and “over molded” onto the ear tip thus resulting in a single part with two dis-similar materials. Alternatives to this process could include, but are not limited to, bonding of an independent insert to the ear tip, or co-injection molding the insert in a tool first, the insert becoming an independent part for a very short period of time, and then finishing the part with the highly elastic material in a secondary molding process. 
         [0028]    Although the examples shown in  FIGS. 1-3  depict a typical “barbed nozzle” feature which is commonly used in headset applications, this invention is not limited to that specific geometry. For example, there are many headset geometries and ear tip geometries, with some ear tips or “boots” encompassing nearly the entire headset with the soft, vibration and sound damping elastic material. Embodiments disclosed herein can encompass such non-traditional geometries and includes any application using the described soft, high vibration and sound damping elastic materials along with memory retaining, higher retention force materials for retention on a headset body. Such applications may include the predefined chemical/mechanical bonding and molding to ear tips, or non-bonded sleeves, clamps or bands to secure the soft, high vibration and sound damping material to the headset. Such embodiments can provide a reliable enough retention force during use to prevent the ear tip from becoming lodged in the users ear or falling off the headset device during removal from the ear. 
         [0029]    From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope hereof. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.