PATENT DOCUMENT

Publication Number: US-8774444-B2
Application Number: US-201213453874-A
Country: US
Kind Code: B2

Title: Vented in-the-ear headphone

Abstract:
A vented tip for in-the-ear headphones has a core portion to be mounted to a sound output tube of an in-the-ear earphone and a flange portion extending outward from and surrounding the core portion. The vented tip has a) an outer portion formed in the flange portion that is to be in contact with, and thereby form a seal with, a user&#39;s ear canal, and b) an inner portion spaced inwards from the outer portion to thereby not form the seal with the user&#39;s ear canal. The inner portion has a calibrated perforation or hole formed therein. Other embodiments that may help reduce bone conduction effects are also described and claimed.

Claims:
What is claimed is: 
     
       1. A vented tip for in-the-ear headphones, comprising:
 a core portion to be mounted to a sound output tube of an in-the-ear headphone; and 
 a flange portion extending outward from and surrounding the core portion, 
 wherein the vented tip has
 a) an outer portion formed in the flange portion that is to be in contact with, and thereby form a seal with, a user&#39;s ear canal, and 
 b) an inner portion spaced inwards from the outer portion to thereby not form the seal with the user&#39;s ear canal, the inner portion having a hole formed therein and wherein the hole is to passively change a frequency response of the in-the-ear headphone such that undesirable effects of bone conduction are reduced. 
 
 
     
     
       2. The vented tip of  claim 1  wherein the core portion and the flange portion are made of the same material. 
     
     
       3. The vented tip of  claim 2  wherein the material is closed-cell foam. 
     
     
       4. The vented tip of  claim 1  wherein the flange portion is a silicone membrane that is more flexible than the core portion. 
     
     
       5. The vented tip of  claim 1  wherein the core and flange portions, including the inner and outer portions, form a single, volume manufactured piece. 
     
     
       6. The vented tip of  claim 1  wherein the hole remains open when the tip is within the user&#39;s ear canal. 
     
     
       7. A vented tip for in-the-ear headphones, comprising:
 a core portion to be mounted to a sound output tube of an in-the-ear headphone; and 
 a flange portion extending outward from and surrounding the core portion, 
 wherein the vented tip has a trench formed on an outer surface of the flange portion that extends across a contact section of the flange portion, the contact section to be in contact with, and thereby form a seal with, a user&#39;s ear canal wall and wherein the trench is to passively change a frequency response of the in-the-ear headphone such that undesirable effects of bone conduction are reduced. 
 
     
     
       8. The vented tip of  claim 7  wherein the trench extends generally longitudinally or in a front-to-back direction across the contact section. 
     
     
       9. The vented tip of  claim 7  wherein one of the structure and material of the contact section prevents the trench from collapsing due to compression forces that are created when the headphone is inserted into the ear canal. 
     
     
       10. The vented tip of  claim 7  wherein the in-the-ear headphone comprises a receiver or driver that receives its input electrical signal directly from an external amplifier. 
     
     
       11. An in-the-ear headphone comprising:
 an in-the-ear headphone housing forming a sound output tube dimensioned to receive a tip, wherein the sound output tube is acoustically coupled to a receiver contained within the housing, an open end of the sound output tube is to be inserted into a wearer&#39;s ear canal, and wherein a vent passage is formed through a wall of the sound output tube, the vent passage having a front bore segment formed in a front portion of the sound output tube and a rear bore segment formed in a rear portion of the sound output tube, the front and rear portions of the sound output tube being connected to each other so that the front and rear bore segments are aligned to thereby vent the ear canal and passively change a frequency response of the in-the-ear headphone. 
 
     
     
       12. The in-the-ear headphone of  claim 11  wherein the tip is mounted to the sound output tube, the latter being a rigid member while the former is a flexible member, the tip having a core portion to be mounted to the sound output tube and a flange portion extending outward from and surrounding the core portion, a contact section of the flange portion to be in contact with, and thereby form a seal with, a wall of the wearer&#39;s ear canal. 
     
     
       13. The in-the-ear headphone of  claim 12  wherein the tip covers a back end of the vent passage, the tip being ported in the core portion at a location that lines up with the back end of the vent passage. 
     
     
       14. The in-the-ear headphone of  claim 11  wherein the vent passage is routed from free air outside the housing, through the wall of the sound output tube, and out a front face of the sound output tube. 
     
     
       15. The in-the-ear headphone of  claim 11  wherein the front portion of the sound output tube is a cap having a mesh or grill surface that defines the open end of the sound output tube. 
     
     
       16. The in-the-ear headphone of  claim 11  wherein the front bore segment has an end that is to always be open to the ear canal and the rear bore segment has an end that is to always be open to the free air outside the housing. 
     
     
       17. The in-the-ear headphone of  claim 11  wherein the front bore segment is one of a plurality of front bore segments having different diameters; and
 wherein the front and rear portions of the sound output tube can be manually rotated relative to each other to align one of the plurality of front bore segments with the rear bore segment to achieve a different venting level. 
 
     
     
       18. A vented tip for in-the-ear headphones, comprising:
 a core portion to be mounted to a sound output tube of an in-the-ear headphone; and 
 a flange portion extending outward from and surrounding the core portion, 
 wherein the vented tip has a trench formed on an inner surface of the core portion that is to contact an outer surface of the sound output tube to thereby form a vent passage to passively change a frequency response of the in-the-ear headphone, the trench running generally longitudinally from a front face of the tip to a rear face of the tip.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The application is a continuation of co-pending U.S. patent application Ser. No. 12/205,547, filed Sep. 5, 2008 and incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     An embodiment of the invention relates to improving the sound quality of insert earphones (also referred to as in-the-ear or in-the-canal headphones) by venting or leakage, to reduce bone conduction effects. 
     BACKGROUND 
     Whether listening to an MP3 player while traveling, or to a high-fidelity stereo system at home, consumers are increasingly choosing the in-ear earphone for their listening pleasure. This electro-acoustic transducer device has a relatively low profile that provides convenience for the wearer, while also providing very good sound quality. An in-the-ear headphone, also referred to as an “earbud”, has a receiver or driver (an earpiece speaker) inside a housing that has an acoustic output tube. The open end of the latter is to be inserted into the wearer&#39;s ear canal. The tube is a rigid member that may be fitted with a flexible and resilient tip or cap typically made of a rubber or silicone material. The tip may be custom molded for the discerning audiophile, or it may be a high volume manufactured piece. The tip has an inner diameter that is slightly smaller than the outer diameter of the output tube. The user stretches the tip outward (in a radial direction), to enable it to easily slide (in a longitudinal direction) over the open end of the housing&#39;s output tube. The tip is then released, which causes it to collapse inward and grip the output tube. When such a headphone is then is inserted into the user&#39;s ear, a flared portion of the ear tip becomes compressed against the ear canal wall and thereby creates a sealed (essentially airtight) cavity inside the canal. This provides the wearer with good acoustic isolation against external sounds. 
     Consumers can wear in-the-ear headphones while conducting various types of daily activity, including not just sitting calmly and listening to music, but also while walking, exercising vigorously, and talking on a telephone call. This increased level of physical activity, however, results in the lower frequency or bass sounds that are being heard by the user to be amplified inadvertently by the headphone. This may be due to the headphone tip forming a very good seal with the user&#39;s ear canal wall, thereby creating an occluded cavity therein. Studies have shown that the sound pressure levels in the ear canal, produced by an external vibration source, are greater in the occluded ear than in the un-occluded or open-to-free-air condition. This effect is also referred to as bone conduction, because the user experiences the effect of external vibrations through the skull or other parts of the user&#39;s body outside the ear canal. 
     SUMMARY 
     Several embodiments of the invention are directed to vented, in-the-ear headphones (earphones) that may reduce or ameliorate the undesirable acoustic effects of bone conduction. 
     One embodiment is a vented tip for an in-the-ear headphone. A core portion of the tip is to be mounted or installed to a sound output tube of an earphone case. A flange portion extends outward from and surrounds the core portion. The vented tip has an outer portion formed in the flange portion that is to be in contact with, and thereby form a seal with, a user&#39;s ear canal (when the tip has been installed to the sound output tube and fitted to the user&#39;s ear). In addition, the vented tip has an inner portion that is spaced inwards from the outer portion to thereby not form the seal with the user&#39;s ear canal (when the tip has been installed to the sound output tube and has been fitted to the user&#39;s ear). In other words, the inner portion is spaced inwards from the outer portion to thereby not be in contact with a wall of the user&#39;s ear canal. This inner portion has a calibrated, front-to-back perforation or hole formed therein. The perforation or hole remains open for venting or leakage, even when the tip has been installed to the earphone sound output tube and has been fitted to the user&#39;s ear. Such an ear tip may be interchanged with a “full seal” tip and may be used when the user is for example exercising vigorously. The headphone may be packaged together with both types of ear tips, to be sold as a single item. 
     In another embodiment, the venting or leakage is achieved using a calibrated, open trench or trough. The trench is formed on the outer surface of the flange portion and extends generally longitudinally or in a front-to-back direction across a contact section of the flange that will be compressed while in contact with the ear canal wall (when the headphone has been inserted into the wearer&#39;s ear). The structure and/or material of at least the contact section should be designed to prevent the trench from collapsing too much (due to the compression forces that are created) when the headphone is inserted into the ear canal, so that sufficient venting takes place through the trench during use of the headphone. 
     In yet another embodiment, a calibrated, front-to-back vent passage is formed through a wall of the earphone case sound output tube. The vent passage is separate from and in addition to the main sound output port of the earphone case. The vent passage may be routed or ported, from the free air outside the case, through the wall of the sound output tube and into the ear canal. In cases where a tip is used that covers the back end of the vent passage, the tip itself may need to be ported at a location that lines up with the back end of the passage, to allow the covered back end to communicate with free air. In that case, the ported portion of the tip may be considered as formed in the core portion of the tip, as compared to the latter&#39;s flange portion. 
     The vent passage that is formed through the wall of the sound output tube has at least two bore segments. A front bore segment may be formed in a cap (e.g., one having a mesh or grill surface as in a typical earphone) that is located in front of a base, both being in effect part of the case sound output tube. The front bore segment may be always open to the occluded cavity in the ear canal. A rear bore segment of the vent passage may be formed in the base and may always be open to the free air outside the earphone case. The cap may be connected to the base so that it can be manually rotated relative to the base by the wearer, between at least two stable positions or states. In one state, which may be called the vigorous exercise or work out position, the front and rear segments are aligned to thereby vent the ear canal cavity. In another state, namely the normal or high fidelity position, at least the front segment is blocked to thereby not vent the ear canal cavity. 
     In a further embodiment, venting is achieved by carefully porting the inner surface of the ear tip so that, once the tip has been installed in a typical manner onto the earphone case sound output tube, a calibrated vent passage or port that runs generally longitudinally or in a front-to-back direction is created when the ported inner surface of the ear tip is joined with the outer surface of the case sound output tube. This passage extends from the front of the case sound output tube, which opens into the ear canal cavity, rearward along the outer surface of the case sound output tube, and then opens to the free air outside the case. In this embodiment, the vent passage may be considered as formed in the core portion of the tip, as compared to the latter&#39;s flange portion. 
     The above summary does not include an exhaustive list of all aspects of the present invention. Indeed, it is contemplated that the invention includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the Detailed Description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above Summary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment of the invention in this disclosure are not necessarily to the same embodiment, and they mean at least one. 
         FIG. 1  shows a side view of a cross section of an example vented ear tip as installed to an earphone case. 
         FIG. 2  is a front view of the outside of the vented ear tip of  FIG. 1 . 
         FIG. 3  is a side view of a cross section of the earphone with the installed vented tip, fitted into a user&#39;s ear canal. 
         FIG. 4  is a front view of the outside of an ear tip having an open trench formed in its outer surface, in accordance with another embodiment of the invention. 
         FIG. 5  is a side view of a cross section of an earphone installed with the vented tip of  FIG. 4 , fitted into a user&#39;s ear canal. 
         FIG. 6  is a side view of a cross section of an earphone having a ported, case sound output tube wall, in accordance with another embodiment of the invention. 
         FIG. 7  is side view of a cross section of an earphone fitted with a tip that is ported along its inner surface, in accordance with another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In this section several embodiments of this invention are explained with reference to the appended drawings. Whenever the shapes, relative positions and other aspects of the parts described in the embodiments are not clearly defined, the scope of the invention is not limited only to the parts shown, which are meant merely for the purpose of illustration. 
       FIG. 1  is a side view of a cross section of an example earphone assembly in accordance with an embodiment of the invention. A vented ear tip  102  has been fitted to an earphone case  104 , making the in-the-ear headphone thus ready to be inserted into the user&#39;s ear canal. The earphone case  104  houses a receiver  106  (also referred to as an earpiece speaker or a driver). The receiver  106  may be fixed in position relative to an inside of the earphone case  104  as shown. The receiver has an electrical signal input port to receive an input electrical audio signal. The receiver converts the input or incoming electrical audio signal into sound pressure waves that are delivered through its at least one receiver sound output port  103 . These open into a sound chamber or other volume inside the case  104  that is further coupled acoustically to a case sound output tube  108 . The shape of the sound chamber and the case sound output tube  108  as well as the material of its interior walls may be designed to promote the quality of sound delivered from the receiver  106  through the port  103  and that is then heard by the wearer or user of the headphone. 
     The case sound output tube  108  need not have a perfectly cylindrical shape, for example as shown in  FIG. 6 . It does have an open far end portion that may be inserted into the ear canal as shown for example in  FIG. 3 . In particular, the far end portion may be partially inserted into the ear canal while it has been fitted with an ear tip  102  as shown. The tube is a rigid member that may be fitted with a flexible and resilient tip typically made of a rubber or silicone material. The entire tip may be a single manufactured piece, which may be custom molded for the discerning audiophile, or high volume manufactured for the average consumer. The tip may have an inner diameter that is slightly smaller than the outer diameter of the output tube. In that case, the user stretches the tip outward (in a radial direction), to enable it to easily slide (in a longitudinal direction) over the open end of the output tube. The tip is then released, which causes it to collapse inward and grip the output tube. The ear tip  102  has a central opening that lines up with the open far end portion of the tube  108 , so that sound pressure waves are directed from the receiver port  103  through an acoustic pathway inside the tube  108 , out of the opening of the latter and into the ear canal. 
     More particularly, and still referring to  FIG. 1 , the vented ear tip  102  has a core portion  110  that is to be mounted (installed or otherwise fitted) to the sound output tube  108  over its open end portion as shown. To ease this process, the sound output tube  108  may be as rigid as or more rigid then the core portion  110  of the tip  102 . Also, the core portion  110 , in this example being essentially cylindrical, has an inner diameter that is slightly smaller than the outer diameter of the sound output tube  108 , so that the inner diameter is stretched or increased slightly when the tip  102  has been fitted onto the tube  108 , as shown. In this embodiment, the core portion  110  should be sufficiently long so as to for example prevent the tip  102  from sliding off the sound output tube  108  during normal use by the wearer inserting the headphone and removing the headphone from her ear canal. 
     The ear tip  102  also has a flange portion  111 , which extends outward from and surrounds the core portion  110 . This is also depicted in the front outside view shown in  FIG. 2 . Both the core portion  110  and the flange portion  111  may be made of the same material. The material may be, for example, closed-cell foam or it may be solid silicone or other suitable resilient material. Alternatively, the flange portion  111  may be made of a different material than the core portion  110 . The flange portion  111  may be a silicone membrane that is more flexible than the core portion  110 . 
     The flange portion  111  of the tip  102  is shaped and sized to allow the wearer to squeeze its outside surface in a generally radial direction, while inserting the headphone assembly (with the tip installed) into the ear canal, to thereby make an airtight seal all around the outside surface of the flange portion which is in contact with the surface of the ear canal wall. When such a headphone is inserted into the user&#39;s ear, the flange portion  111  becomes compressed against the ear canal wall (e.g., as shown in  FIG. 3 ) and thereby creates a sealed or essentially airtight cavity inside the canal. This provides the wearer with good acoustic isolation against external sounds. 
     Still referring to  FIG. 1 , bone conduction effects may be ameliorated by providing a vent  112  as follows. The tip  102  has an outer portion formed in the flange portion that is to be in contact with, and thereby form a seal with, the user&#39;s ear canal (when the tip has been installed to the sound output tube and fitted to the user&#39;s ear, as shown in  FIG. 3 ). In addition, the tip has an inner portion that is spaced inwards from the outer portion to thereby not form the seal with the user&#39;s ear canal—see  FIG. 3 . In other words, the inner portion is spaced inwards from the outer portion to thereby not be in contact with a wall of the user&#39;s ear canal. This inner portion has a calibrated, front-to-back perforation or hole formed therein, referred to as the vent  112 . 
     The vent  112  remains open for venting, even when the tip has been installed to the earphone sound output tube and has been fitted to the user&#39;s ear. This may be achieved by for example using a different material and/or construction for the inner portion (perhaps including the entire core portion  110 ) than for the outer portion (perhaps including the entire flange portion  111 ). The vent  112  is calibrated in the sense that it has been tested or evaluated (in at least one specimen of a manufactured lot) for compliance with a given specification or design parameter. In other words, it is not just a random hole, but it has been intentionally formed for a particular purpose, namely to change the frequency response of the headphone in a way that helps reduce the undesirable effects of bone conduction. For example, the vent  112  may cause the bass response to dovetail downwards, while not substantially impacting the high frequency response, thus reducing and may effectively eliminate low-end bass heard by the wearer, for example below 200 Hz. This is an acceptable loss in performance because it reduces bone conduction effects. 
     In another embodiment, venting is achieved using a calibrated, open trench or trough  412 . This is depicted in  FIG. 4  which is a front view of the outside of an ear tip having the open trench  412  formed in its outer surface. The trench is formed on the outer surface of the flange portion  111  and extends generally longitudinally or in a front-to-back direction across a contact section  413  of the flange, as depicted in  FIG. 5 . The contact section  413  is the intermediate section of the flange portion  111  that will be compressed while in contact with the ear canal wall (when the headphone has been inserted into the wearer&#39;s ear as shown). The structure and/or material of at least the contact section  413  should be designed to prevent the trench  412  from collapsing too much (due to the compression forces that are created) when the headphone is inserted into the ear canal, so that sufficient venting takes place through the trench during use of the headphone. The trench  412  should be sized and shaped so that when it is in contact with the ear canal wall as depicted in  FIG. 5 , it and the contacted surface of the ear canal wall define a vent hole that causes the bass response of the headphone to dovetail downwards, while not substantially impacting the high frequency response, thus reducing or perhaps effectively eliminating low-end bass heard by the wearer, for example below 200 Hz. 
     In yet another embodiment, a calibrated, vent passage  612  is formed through a wall of the earphone case sound output tube  108 . An example of this embodiment is depicted in  FIG. 6 , which is a side view of a cross section of an earphone having a ported, case sound output tube wall. The vent passage  612  is of course separate from and in addition to the main sound output port of the earphone case  606 . In this example, the vent passage  612  is routed or ported, from the free air outside the case, through the wall of the sound output tube  108  and then out the front face of a mesh cap  608  that is connected to and in front of a base  609  of the sound output port  108 . Alternatively, instead of out the front face, the vent passage  612  could be routed out the side of the mesh cap  608 . In both cases, the vent passage  612  is sized to cause the bass response of the earphone to dovetail downwards, while not substantially impacting the high frequency response, thus reducing and perhaps effectively eliminating low-end bass heard by the wearer, for example below 200 Hz. 
     In cases where a tip is used that covers the back end of the vent passage  612 , the tip itself may need to be ported at a location that lines up with the back end of the passage  612 , to allow the covered back end to communicate with free air, as shown in  FIG. 6 . In that case, the porting within the tip may be considered as formed in the core portion  110  of the tip, as compared to the latter&#39;s flange portion  611 . 
     The vent passage that is formed through the wall of the sound output tube has at least two bore segments. A front bore segment may be formed in a cap (e.g., one having a mesh or grill surface as in a typical earphone) that is located in front of a base, the latter being part of the case sound output tube. The front bore segment is open to the occluded cavity in the ear canal. A rear bore segment of the vent passage may be formed in the base and is open to the free air outside the earphone case. The cap may be connected to the base so that it can be manually rotated relative to the base by the wearer, between at least two stable positions or states. In one state, the front and rear segments are aligned to thereby vent the ear canal cavity, while in another state front segment is blocked to thereby not vent the ear canal cavity. This allows the wearer to use the headphone for both a high fidelity mode of operation and a work out or telephone call mode, without having to change the ear tip. 
     Although two stable venting states have been described in connection with the embodiment of  FIG. 6 , additional states may also be defined at different rotation positions, corresponding to different degrees of venting. This may be implemented by having one or more additional, front bore segments formed in the cap, each at a different radial angle about the center axis of the cap and each having a different diameter to achieve a different venting level. This allows the wearer to fine tune the level of venting of her headphone, without having to change the ear tip. 
     In a further embodiment, venting is achieved by carefully porting the inner surface of the ear tip. This is depicted by the example in  FIG. 7 , which is side view of a cross section of an earphone fitted with a tip that is ported along its inner surface. Once the tip has been installed in a typical manner onto the earphone case sound output tube  108 , a calibrated vent passage or port  712  that runs generally longitudinally or in a front-to-back direction is created, when a trenched inner surface of the ear tip is joined with the outer surface of the case sound output tube, as shown in the figure. This passage  712  extends from the front face of the case sound output tube, which may be located in the ear canal cavity, rearward along the outer surface of the case sound output tube  108 , and then opens to the free air outside the case. In this embodiment, the vent passage may be considered as partially formed in the core portion of the tip, as compared to the latter&#39;s flange portion. Finally, the trenching of the core portion of the tip should be sized and shaped so that when it is in contact with the outer surface of the case sound output tube, it and the contacted surface define a vent hole that causes the bass response of the headphone to dovetail downwards, while not substantially impacting the high frequency response, thus reducing or perhaps effectively eliminating low-end bass heard by the wearer, for example below 200 Hz. 
     In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the invention as set forth in the following claims. For instance, although the flange portions  111 ,  611 , and  711  have been illustrated in the figures as being relatively thin and membrane-like, an alternative here is to have a thicker foam design. In addition, in contrast to a hearing aid, which produces an electrical audio signal from a built-in pick-up and then converts the signal into sound waves, the receiver or driver in an earphone or headphone receives its input electrical signal directly from an external amplifier. This may be via a cable that is connected to a headphone jack of an external, portable, consumer grade digital media storage and playback device such as an IPOD player or an IPHONE communications device (that may also be worn or held by the wearer of the headphone). As an alternative, the earphone may be integrated with a wireless interface (e.g., as a Bluetooth headset) to receive the electrical signal via a wireless connection with the external amplifier. In addition, a passive or active crossover circuit may be built into the headphone housing or the receiver&#39;s case, to receive and filter the external electrical signal (prior to being input to a motor of the receiver or driver). The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

Metadata:
Filing Date: 20120423
Publication Date: 20140708
Grant Date: 20140708
Priority Date: 20080905
Inventors: TISCARENO VICTOR M.
STIEHL KURT R.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R1/1016", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/1016", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 41799320