Patent Publication Number: US-2023133906-A1

Title: Ear mount

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is based on, and claims priority from the prior Japanese Patent Application Nos. 2021-177786, 2021-177874, and 2021-177894, all filed on Oct. 29, 2021, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     The present disclosure relates to an ear mount. 
     Japanese Unexamined Patent Application Publication No. 2014-057164 discloses an ear mount such as an earplug, an earphone, or a hearing aid. In this ear mount, an insertion part inserted into the ear canal has a soundproof member and an elastic member covering the soundproof member. The elastic member is expanded by causing air to flow into the inside of the elastic member and thus the elastic member is in close contact with the inner wall of the ear canal. Accordingly, the wearing sensation is improved. 
     SUMMARY 
     An ear mount generally has an insertion part that is inserted into the ear canal and a body part that is fitted into the conchal cavity of the auricle. The ear mount disclosed in Japanese Unexamined Patent Application Publication No. 2014-057164 improves the wearing sensation of the insertion part inserted into the ear canal, but does not improve the wearing sensation of the body part fitted into the conchal cavity. 
     An ear mount in accordance with some embodiments includes: a body part mounted on a conchal cavity in a use state and including a protrusion, a cylindrical part extending from the protrusion, an inner housing on which the protrusion is formed, and a cover configured to cover the inner housing; and an insertion part mounted on the cylindrical part and inserted into an ear canal in the use state. The cover includes a first end sealed and fixed to the inner housing, an intermediate part separated from the inner housing to form an air chamber between the intermediate part and the inner housing and configured to cover the protrusion, a second end located opposite to the first end with the intermediate part therebetween, and an opening located at the second end and through which the cylindrical part is inserted. The ear mount includes a pressure regulator configured to control ventilation of air between the air chamber and an outer space through the opening in accordance with a pressure difference between the air chamber and the outer space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates a state in which an earplug of an ear mount according to Embodiment 1 is mounted on a right auricle. 
         FIG.  2    is a perspective view of an earplug according to Embodiment 1. 
         FIG.  3    is an assembly view of a body part of an earplug according to Embodiment 1. 
         FIG.  4    is a partial cross-sectional view of a body part along line S 4 -S 4  of  FIG.  2   . 
         FIG.  5    is a cross-sectional view along line S 5 -S 5  in  FIG.  4   . 
         FIG.  6 A  is a cross-sectional view along line S 6 -S 6  in  FIG.  2   , and is a longitudinal cross-sectional view of when an earplug is normally mounted on an auricle. 
         FIG.  6 B  is a cross-sectional view along line S 6 -S 6  in  FIG.  2   , and is a longitudinal cross-sectional view of one process in mounting an earplug on an auricle. 
         FIG.  7 A  is a cross-sectional view of an earplug according to Embodiment 2, and is a longitudinal cross-sectional view of when an earplug is normally mounted on an auricle. 
         FIG.  7 B  is an enlarged view of part of  FIG.  7 A . 
         FIG.  7 C  is a cross-sectional view of an earplug according to Embodiment 2, and is a longitudinal cross-sectional view of one process of mounting an earplug on an auricle. 
         FIG.  8 A  is a cross-sectional view of an earplug according to Embodiment 3, and is a longitudinal cross-sectional view of when an earplug is normally mounted on an auricle. 
         FIG.  8 B  is a plan view of a filter member used in a valve structure of an earplug according to Embodiment 3. 
         FIG.  9    is a partial perspective view illustrating an inner housing of a valve structure of an earplug according to Embodiment 4. 
         FIG.  10    is a cross-sectional view of an earplug according to Embodiment 4. 
         FIG.  11    is a partial perspective view of an earplug according to Embodiment 5. 
         FIG.  12    is a cross-sectional view of an earplug according to Embodiment 5. 
     
    
    
     DETAILED DESCRIPTION 
     An ear mount according to embodiments of the present invention will be described below with reference to the drawings. 
     Embodiment 1 
     An outline of an earplug  91  according to Embodiment 1 will be described with reference to  FIGS.  1  and  2   . The earplug  91  described below is for the right ear, and earplugs for the right ear and the left ear have a left/right symmetrical shape. For convenience of explanation, the front, rear, up, down, left, and right directions are defined as the directions of the arrows illustrated in  FIGS.  1  and  2   . The up-down direction is the vertical direction when the wearer of the earplug  91  is in the standing position. The front-rear direction corresponds to the front-rear direction of the head. The left-right direction corresponds to the left-right direction of the head. In  FIGS.  1 ,  2 ,  4  and  5   , the front, rear, up, down, right, and left directions are denoted by FR, RR, UP, DN, RT, and LT, respectively. 
     While being mounted on an auricle E, the earplug  91  has a body part  911  that is fitted in a conchal cavity Eb and an insertion part  912  that protrudes from the body part  911  and is inserted into an ear canal. The insertion part  912  is formed of silicone rubber or the like and has elasticity. The insertion part  912  is detachably attached to the body part  911 . The state in which the earplug  91  is mounted on the auricle E is also referred to as a use state. 
     As illustrated in  FIG.  2   , the body part  911  has a base  911   a , a protrusion  911   b , and a locking protrusion  911   c . The base  911   a  has an ellipsoidal shape obtained by forming an oval into a flatted solid shape. The protrusion  911   b  protrudes toward the left and obliquely upward and is formed at a position biased to the front of the surface facing the conchal cavity Eb when the earplug is mounted on the auricle E. The locking protrusion  911   c  protrudes from the end side of the protrusion  911   b  in the protrusion direction along the axial direction of the protrusion  911   b  and has a smaller diameter than the protrusion  911   b . The insertion part  912  is elastically locked to the locking protrusion  911   c.    
     With the earplug  91  illustrated in  FIG.  1    mounted on the auricle E, the insertion part  912  is inserted into the ear canal and the base  911   a  of the body part  911  is fitted in the conchal cavity Eb. The front side of the base  911   a  enters between the conchal cavity Eb and a tragus Ec so as to be sandwiched therebetween, and the rear side of the base  911   a  enters the inner side of an anthelix Ea, which projects to cover the conchal cavity Eb. Accordingly, the earplug  91  is stably mounted on the auricle E as long as no excessive external force in the direction of separation is applied. 
     The body part  911  includes an outer housing  1 , an inner housing  2 , and a cover  3  as illustrated in  FIG.  3   . The outer housing  1  and the inner housing  2  are formed of a hard resin. The hard resin is a polycarbonate (PC), for example. The cover  3  is formed of a flexible material. Examples of such a material include elastomers, silicone rubber, and the like. 
       FIG.  4    is a partial cross-sectional view of the body part  911  along line S 4 -S 4  of  FIG.  2   . As illustrated in  FIG.  4   , the outer housing  1  has a nearly flat bottom wall  1   a  and an outer peripheral wall  1   e  that is raised and curved from the entire outer edge of the bottom wall  1   a . The outer peripheral wall  1   e  has a circumferential step part  1   d  which is hollowed out along the whole circumference of the outer peripheral wall  1   e  toward the right, at the inner edge of the left tip surface of the outer peripheral wall  1   e . At a position on the bottom wall  1   a , which is separated from the outer peripheral wall  1   e  and inside of the outer peripheral wall  1   e , an inner rib  1   b  protruding to the left at a height lower than the outer peripheral wall  1   e  is formed along the entire outer edge of the bottom wall  1   a.    
     As illustrated in  FIGS.  3  and  4   , the inner housing  2  has a base  21   d  and an engagement projection  21   b . The base  21   d  faces the bottom wall  1   a  of the outer housing  1 . The engagement projection  21   b  protrudes toward the right near the peripheral edge of the base  21   d  along the whole circumference of the base  21   d . The peripheral edge of the base  21   d  forms an outer flange  21   a  protruding more outward than the engagement projection  21   b . At a position biased to the front of the base  21   d , a cylindrical protrusion  22  is formed which protrudes to the left and obliquely upward. From the tip surface of the protrusion  22 , a cylindrical part  23  with a smaller diameter than the protrusion  22  extends along the axis of the protrusion  22 . The above described locking protrusion  911   c  visible as part of the external appearance is this cylindrical part  23 . 
     As illustrated in  FIG.  4   , the outer housing  1  and the inner housing  2  can be combined by entering the engagement projection  21   b  of the inner housing  2  into a circumferential recess  1   c  for the engagement projection  21   b  to engage with the circumferential recess  1   c . The circumferential recess  1   c  is a recess between the outer peripheral wall  1   e  of the outer housing  1  and the inner rib  1   b . While the outer housing  1  and the inner housing  2  are combined, the circumferential step part  1   d  of the outer housing  1  and the circumferential step part  21   c  of the inner housing  2  face each other in the left-right direction with a gap therebetween. 
     As illustrated in  FIGS.  3  and  4   , the cover  3  has a cover base  31  as an intermediate part in the left-right direction and a cylindrical protrusion  32 . The cover base  31  has the same outer shape as the outer housing  1 . The cylindrical protrusion  32  has a bottomed cylindrical shape protruding toward the left and obliquely upward from a position biased to the front of the cover base  31 . An opening  34  is formed in a shoulder  32   b , which serves as a wall to cover the end of the cylinder of the cylindrical protrusion  32 . The inner diameter of the opening  34  is larger than the outer diameter of the cylindrical part  23  of the inner housing  2 . 
     The cover base  31 , as illustrated in  FIG.  4   , has an inner flange  31   a  protruding inward along the whole circumference at the peripheral edge of the cover base  31 , and a circumferential rib  31   b  that protrudes along the whole circumference of the inner flange  31   a  to the right from the inner edge of the inner flange  31   a . The circumferential rib  31   b  is a first end on the right side in the left-right direction. The cylindrical protrusion  32  is a second end opposite to the first end with the intermediate part (the cover base  31 ) therebetween. The circumferential rib  31   b  fits in the gap formed between the circumferential step part  1   d  and the circumferential step part  21   c  when the outer housing  1  and the inner housing  2  are combined. The outer housing  1  and the inner housing  2  can be closely combined with the cover base  31  therebetween. 
     The body part  911  of the earplug  91  is formed by combining and integrating, by means of welding or bonding, the outer housing  1  and the inner housing  2  with the circumferential rib  31   b  of the cover base  31  therebetween. In other words, the circumferential rib  31   b  is sealed and fixed by being fitted in the gap formed between the circumferential step part  1   d  on the inner housing  2  side and the circumferential step part  21   c  of the inner housing  2 . In the body part  911  obtained by integrating the outer housing  1  and the inner housing  2  with the cover  3  interposed therebetween, the cylindrical part  23  of the inner housing  2  is inserted into the opening  34  of the cover  3  in a natural state in which no external force is applied. In the natural state, the cover base  31  of the cover  3  is separated to the left from the base  21   d  of the inner housing  2 . That is, an air chamber V as a space is formed between the cover base  31  and the base  21   d  in the natural state. 
       FIG.  5    illustrates the formation range of the air chamber V, for example.  FIG.  5    is a cross-sectional view along line S 5 -S 5  of  FIG.  4    as viewed from the left side at a position slightly to the left from the base  21   d  of the inner housing  2 . As illustrated in  FIG.  5   , the air chamber V is formed in a wide area corresponding to the external shape of the base  911   a . The cover  3  is formed of a material with a certain degree of flexibility, and the shape of the air chamber V is well maintained in the natural state. 
     The air chamber V extends to the left along the protrusion  22  of the inner housing  2  as illustrated in  FIG.  4   . The cover  3  is in close contact with the protrusion  22  at a position close to the tip of the protrusion  22  in the natural states. That is, the left-hand edge position of the air chamber V in the natural state is a boundary position at which the cover  3  is in close contact with the protrusion  22  at a position close to the tip of the protrusion  22 . The inner flange  31   a  side of the cover base  31  of the cover  3 , which is the right-hand edge side, is interposed and sealed between the inner housing  2  and the outer housing  1 . 
     The tip side portion of the cylindrical protrusion  32  including the opening  34  in the cover  3  and the inner housing  2  work together to form a valve structure (a pressure regulator) BK that controls the entry and exit of the air between the interior of the air chamber V and an outer space. That is, the earplug  91  has the air chamber V and the valve structure BK that control the entry and exit of air in/from the air chamber V. 
     The valve structure BK is described with reference to  FIG.  6 A .  FIG.  6 A  is a longitudinal cross-sectional view of the protrusion  911   b  of the body part  911 , and specifically is a cross-sectional view along line S 6 -S 6  in  FIG.  2   . 
     The protrusion  22  of the inner housing  2  has a cylindrical part  22   a  extending in a cylindrical shape with an axis CL 22  as the axis, a top wall  22   t  which is substantially perpendicular to the axis CL 22  and substantially covers the cylinder, and a shoulder  22   b  curving and smoothly connecting the tip of the cylindrical part  22   a  and the edge of the top wall  22   t . In the natural state of the earplug  91 , the cover  3  is mounted such that an outer surface  22   t   1  of the top wall  22   t  and the tip side portion of an outer surface  22   b   1  of the shoulder  22   b  (a portion closer to the tip side than a close contact boundary line LN 1  in  FIG.  6 A ) are in close contact with the protrusion  22  of the inner housing  2 . The close contact boundary line LN 1  is a line indicating the position at which the cover  3  begins to contact the protrusion  22 . 
     Specifically, the inner surface of the cylindrical protrusion  32  of the cover  3  is formed in the same shape as the outer surface of the protrusion  22  of the inner housing  2  on the side closer to the tip than the close contact boundary line LN 1 . A side part  32   a  of the cylindrical protrusion  32  is in close contact with the cylindrical part of the protrusion  22  with the close contact boundary line LN 1  as a boundary. The shoulder  32   b  of the cylindrical protrusion  32  is in close contact with the shoulder  22   b  of the protrusion  22 . Accordingly, in the earplug  91 , the valve structure BK is closed in the natural state, the air chamber V is sealed, and no internal air is leaked to the outside. 
     The opening  34  of the cover  3  is coaxial with the cylindrical part  23  of the inner housing  2  and is formed to have an inner diameter larger than the outer diameter of the cylindrical part  23 . Therefore, a gap F 1  of a distance Dl in the radial direction is formed between the base part of the cylindrical part  23  and the end face of the opening  34 . 
     When the earplug  91  having the valve structure BK is mounted on the auricle E, the user grips the body part  911  with the fingers and presses the body part  911  to fit into the conchal cavity Eb while inserting the insertion part  912  into the ear canal. When the body part  911  is pressed against the conchal cavity Eb, the cover base  31  of the cover  3  is pressed against the surface of the conchal cavity Eb and is elastically deformed such that the distance between the cover base  31  and the base  21   d  of the inner housing  2  is reduced. This compresses the air chamber V. When the compression of the air chamber V proceeds and the pressure of the internal air rises to exceed a certain pressure, the valve structure BK opens and the air inside the air chamber V is discharged to the outside. This state is illustrated in  FIG.  6 B . 
     When the internal pressure of the air chamber V rises and reaches a prescribed value, the internal pressure pushes and expands the cylindrical protrusion  32  of the cover  3  against the elastic repulsive force of the area of the cylindrical protrusion  32  and an air passage fa is formed between the cylindrical protrusion  32  and the inner housing  2  as illustrated in  FIG.  6 B . That is, the cylindrical protrusion  32  is expanded and deformed to form the air passage fa. The air passage fa communicates between the air chamber V and an outer space Vg through the opening  34 . Accordingly, the air inside the air chamber V is discharged to the outside through the air passage fa, and the pressure inside the air chamber V falls. 
     Due to the earplug  91  having the valve structure BK, the load on the head is reduced when the earplug  91  is mounted on the auricle E or when the body part  911  of the earplug  91  is pressed against the conchal cavity Eb while the earplug  91  is mounted on the auricle E. More specifically, when the body part  911  is pressed against the conchal cavity Eb, the air chamber V is compressed but sealed and shrinks elastically because there is no air discharge path. In accordance with this, an elastic repulsive force of the air chamber V and the cover  3  is applied to the conchal cavity Eb, and therefore the contact feel of the body part  911  is soft and good. In this way, it is possible to enhance the wearing sensation of the body part  911  fitted in the conchal cavity Eb. 
     When the body part  911  is further strongly pressed against the conchal cavity Eb, the pressure in the air chamber V reaches a prescribed value, the valve structure BK opens, and the internal air of the air chamber V is gradually discharged to the outside. Therefore, the pressure inside the air chamber V is reduced. In accordance with this, the repulsive force applied to the conchal cavity Eb gradually decreases without becoming excessive in spite of the strong pressing. Therefore, the contact feel of the body part  911  is maintained in a good state. In this way, it is possible to enhance the wearing sensation of the body part  911  fitted in the conchal cavity Eb. 
     In a state in which the earplug  91  is mounted on the auricle E, the entire cover  3  in the circumferential direction in the valve structure BK is not uniformly in close contact with the inner wall of the auricle E. Therefore, the air passage fa is not formed in the entire circumferential direction, but first in the area where there is a gap between the cover  3  and the inner wall of the auricle E. For the discharge of the pressurized air in the air chamber V, it is sufficient if the air passage fa is formed in part in the circumferential direction. 
     After time has elapsed or when the earplug  91  is removed from the auricle while the air passage fa is formed, the air chamber V expands from the collapsed state by means of a restoring force that tries to return the shape of the cover  3  to the initial shape. At that time, while the deformation of the shoulder  32   b  remains, the air passage fa is maintained and air flows into the air chamber V from the opening  34 . When the shape of the cover  3  returns to the original shape, the air passage fa is covered and the air chamber V becomes sealed again. 
     As a mode of use in which the body part  911  is pressed more strongly against the conchal cavity Eb while the earplug  91  is mounted on the auricle E, there is a mode in which the user lies on the his/her side while wearing the earplug  91 , and the user&#39;s head is resting on a pillow. In this mode, the earplug  91  is pressed against the head by means of the pillow. In this mode, by the earplug  91  having the air chamber V and the valve structure BK, the body part  911  makes soft contact with the conchal cavity Eb. Accordingly, the user can have a good wearing sensation. 
     Embodiment 2 
     An earplug  91 B according to Embodiment 2 is described. The earplug  91 B is the same as the earplug  91  of Embodiment 1 except that the earplug  91 B has a valve structure (a pressure regulator) BK 2  instead of the valve structure BK. The valve structure BK 2  is described with reference to  FIGS.  7 A to  7 C .  FIGS.  7 A to  7 C  are cross-sectional views of the area near the shoulder  22   b  of the inner housing  2  and illustrate the valve structure BK 2 .  FIG.  7 A  is a longitudinal cross-sectional view of a state in which the earplug  91 B is normally mounted on the auricle E.  FIG.  7 B  is an enlarged view of part of  FIG.  7 A .  FIG.  7 C  is a longitudinal cross-sectional view of the process of mounting the earplug  91 B on the auricle E. 
     As illustrated in  FIGS.  7 A and  7 B , the valve structure BK 2  has a cover  3 B instead of the cover  3  of the valve structure BK. A side part  32   a  and a shoulder  32   b  of the cover  3 B are formed so as to create a gap F 2  along the whole circumference of the protrusion  22 , spaced apart from the protrusion  22  of the inner housing  2  in the natural state. Accordingly, the valve structure BK 2  has an air passage fb communicating with the air chamber V, between the cover  3 B and the protrusion  22 . 
     An opening  34 B with an inner diameter slightly smaller than the outer diameter of the cylindrical part  23  of the inner housing  2  is formed in the shoulder  32   b  of the cover  3 B. The peripheral edge of the opening  34 B is a ring-shaped flap  35  that is thin and easily flexed and deformed. In the present embodiment, there are two flaps that are a thin inner flap  35   a  and outer flap  35   b  which are spaced apart in the thickness direction. The number of flaps is not limited. 
     By using the peripheral edge of the opening  34 B including the inner flap  35   a  and the outer flap  35   b  being in close contact with the outer wall of the cylindrical part  23  in the natural state, the space on the air passage fb side is separated from the outer space Vg. When a prescribed pressure difference occurs between the space on the air passage fb side of the opening  34 B and the outer space Vg, the inner flap  35   a  and the outer flap  35   b  are bent to allow ventilation in a direction that reduces the pressure difference, and a gap is formed between the inner and outer flaps  35   a ,  35   b  and the outer wall of the cylindrical part  23 . This gap is not limited to a gap along the whole circumference of the outer wall of the cylindrical part  23 , and may be formed in a portion in the circumferential direction. 
     When the earplug  91  is mounted on the auricle E, if the cover  3 B is pressed against the conchal cavity Eb, the air chamber V is collapsed, and the air chamber V is pressurized, the inner flap  35   a  and the outer flap  35   b  deform such that the pressurized air in the air chamber V is discharged into the outer space Vg as an airflow ARb, as illustrated in  FIG.  7 C , for example. 
     If the earplug  91  is removed from the auricle E while the cover  3 B is pressed and the air chamber V is deformed, the air chamber V of the cover  3 B is expanded and decompressed from the collapsed state by means of the restoring force that tries to restore the shape to the original shape. Accordingly, the inner flap  35   a  and the outer flap  35   b  are deformed to allow air inflow from the outer space Vg to the air chamber V. When the shape of the cover  3 B returns to the original shape, the difference between the pressure in the air chamber V and the pressure of the outer space Vg becomes small, the inner flap  35   a  and the outer flap  35   b  are in close contact with the cylindrical part  23  again, and the air chamber V becomes sealed again. 
     Due to the earplug  91 B having the valve structure BK 2 , the load on the head is reduced when the earplug  91 B is mounted on the auricle E or when the body part  911  of the earplug  91 B is pressed against the conchal cavity Eb while the earplug  91 B is mounted on the auricle E. Specifically, when the body part  911  is pressed against the conchal cavity Eb, the air chamber V is compressed, but until a prescribed pressure difference occurs between the air chamber V and the outer space Vg, the sealing of the air chamber V is maintained and there is no air discharge path, and therefore the air chamber V shrinks elastically. In accordance with this, an elastic repulsive force is applied to the conchal cavity Eb from the cover  3 . Therefore, the contact feel is soft and good. 
     Suppose that the body part  911  is pressed more strongly against the conchal cavity Eb, the inside of the air chamber V is pressurized more, and a prescribed pressure difference occurs between the air chamber and the outer space Vg. In the above case, the inner flap  35   a  and the outer flap  35   b  of the valve structure BK 2  are opened to discharge the internal air of the air chamber V to the outside. Therefore, the air chamber V is decompressed. In accordance with this, the repulsive force applied to the conchal cavity Eb decreases without becoming excessive despite the strong pressing of the body part  911 , and a good contact feel is maintained. 
     There is one mode of use (lying on one&#39;s side) that has been described as an example in the description of Embodiment 1 as a mode of use in which the body part  911  is pressed more strongly against the conchal cavity Eb while the earplug  91 B is mounted on the auricle E. In this case as well, due to the earplug  91 B having the air chamber V and the valve structure BK 2 , the body part  911  comes into soft contact with the conchal cavity Eb. Accordingly, the wearing sensation is enhanced. 
     Embodiment 3 
     An earplug  91 C according to Embodiment 3 will be described. The earplug  91 C is the same as the earplug  91  according to Embodiment 1 except the earplug  91 C has a valve structure (a pressure regulator) BK 3  instead of the valve structure BK, and therefore the explanation of the earplug  91 C is omitted. The valve structure BK 3  will be described with reference to  FIGS.  8 A and  8 B .  FIG.  8 A  is a cross-sectional view of an area near the shoulder  22   b  of the inner housing  2  for explaining the valve structure BK 3  of Embodiment 3, and is a longitudinal cross-sectional view of when the earplug is normally mounted on the auricle.  FIG.  8 B  is a plan view of a filter member  5  used in the valve structure BK 3 . 
     As illustrated in  FIG.  8 A , the valve structure BK 3  has a cover  3 C instead of the cover  3  of the valve structure BK, and additionally has the filter member  5 . The side part  32   a  and the shoulder  32   b  of the cover  3 C are formed to be separated from the protrusion  22  of the inner housing  2  in the natural state. Accordingly, a gap F 3  is formed between the cover  3 B and the protrusion  22 , and the filter member  5  is interposed in the gap F 3 . 
     As illustrated in  FIG.  8 B , the filter member  5  is formed in the gap F 3  between the cover  3 C and the protrusion  22  to have an approximate bowl shape that is in close contact with both the cover  3 C and the protrusion  22 . At the bottom center of the bowl-shaped filter member  5 , an opening  5   a  is formed through which the cylindrical part  23  can be inserted. The filter member  5  is formed of a material through which air can pass while receiving resistance. That is, the filter member  5  is a vent resistor. Examples of such materials are porous materials such as urethane foam. 
     In this way, the valve structure BK 3  has the filter member  5  between the air chamber V and the outer space Vg. The filter member  5  functions as an air passage fc that allows ventilation between the air chamber V and the outer space Vg with resistance. Therefore, when the earplug  91 C is fitted into the conchal cavity Eb, even if the cover  3 C is pressed in contact with the conchal cavity Eb and the air chamber V is compressed and deformed, the air in the air chamber V is discharged to the outer space Vg over time due to the resistance of the filter member  5 . Therefore, the air chamber V shrinks gradually and elastically. As a result, an elastic repulsive force in accordance with the compressive deformation of the air chamber V is applied to the conchal cavity Eb from the cover  3 . Therefore, the contact feel is soft and good. 
     In the valve structure BK 3  of the earplug  91 C, if the earplug  91 C is removed from the auricle E while the cover  3 C is pressed and deformed, the air chamber V expands from the collapsed state by means of the restoring force that tries to return the shape of the cover  3 C to the initial shape, and the air chamber V is decompressed. As a result, outside air flows into the air chamber V through the filter member  5 , and the state of the cover  3 C returns to the original state. 
     Embodiment 4 
     An earplug  91 D according to Embodiment 4 will be described. The earplug  91 D is the same as the earplug  91  according to Embodiment 1 except the earplug  91 D has a valve structure (a pressure regulator) BK 4  instead of the valve structure BK, and therefore the explanation of the earplug  91 D is omitted. The valve structure BK 4  will be described with reference to  FIGS.  9  and  10   .  FIG.  9    is a partial perspective view illustrating an inner housing  2 D of the valve structure BK 4  of Embodiment 4.  FIG.  10    is a cross-sectional view of the area near the shoulder  22   b  of the inner housing  2 D for explaining the valve structure BK 4 . 
     The valve structure BK 4  has an inner housing  2 D instead of the inner housing  2  in the valve structure BK. Both structures use the cover  3 . As illustrated in  FIG.  9   , the inner housing  2 D differs from the inner housing  2  in that the inner housing  2 D has a groove  25 . The groove  25  is formed on the outer surface of the protrusion  22 . The groove  25  extends from the base part of the cylindrical part  23  through the shoulder  22   b  of the protrusion  22  to the cylindrical part  22   a  and extends in a direction away from the opening  34  in the radial direction. The groove  25  is a narrow groove which is recessed inward from the outer surface of the protrusion  22 . The cross-sectional shape of the groove  25  is not limited, but is rectangular, for example. 
     As illustrated in  FIG.  10   , the valve structure BK 4  and the valve structure BK use the same cover  3 . That is, the cover  3  and the protrusion  22  are in close contact with each other in the natural state at the portions where the groove  25  is present. The end of the groove  25  on the cylindrical part  22   a  side, which is the side far from the opening  34 , communicates with the air chamber V in the natural state or can communicate by means of the expanded deformation of the cover  3 . Meanwhile, the end of the groove  25  on the cylindrical part  23  side extends to a position visible from the outside through the opening  34  of the cover  3  and communicates with the outer space Vg. That is, the air chamber V and the outer space Vg communicate through the groove  25 . The groove  25  as an air passage fd has a small cross-sectional area, and a large resistance is generated for ventilation between the air chamber V and the outer space Vg. 
     In this way, the valve structure BK 4  has the groove  25 , and the groove  25  serves as the air passage fd that allows the ventilation between the air chamber V and the outer space Vg by imparting a large resistance. Therefore, suppose that when the earplug  91 D is fitted into the conchal cavity Eb, the air chamber V is compressed and deformed while the cover  3  is pressed in contact with the conchal cavity Eb. Even in the above case, the air in the air chamber V is not immediately released to the outer space Vg due to the large resistance when passing through the groove  25 , the pressurized state of the air chamber V is maintained for a certain time, and the air chamber V gradually and elastically shrinks. This imparts an elastic repulsive force to the conchal cavity Eb. Therefore, the contact feel is soft and good. 
     In the valve structure BK 4  of the earplug  91 D, if the earplug  91 D is removed from the auricle E while the cover  3  is pressed and deformed, the air chamber V expands from the collapsed state by means of the restoring force of the cover  3  that tries to return the shape to the initial shape, and the air chamber V is decompressed. As a result, outside air flows gradually into the air chamber V through the groove  25 , and the state of the cover  3  returns to the original state. 
     Embodiment 5 
     An earplug  91 E according to Embodiment 5 will be described. The earplug  91 E is the same as the earplug  91  of Embodiment 1 except the earplug  91 E has a valve structure (a pressure regulator) BK 5  instead of the valve structure BK, and therefore the explanation of the earplug  91 E is omitted. The valve structure BK 5  will be described with reference to  FIGS.  11  and  12   .  FIG.  11    is a partial perspective view illustrating an inner housing  2 E of the valve structure BK 5 .  FIG.  12    is a cross-sectional view of the area near the shoulder  22   b  of the inner housing  2 E for explaining the valve structure BK 5 . 
     The valve structure BK 5  has the inner housing  2 E instead of the inner housing  2  in the valve structure BK. As illustrated in  FIG.  11   , the inner housing  2 E is the same as the inner housing  2  except the inner housing  2 E has a plurality of grooves (groove group)  26 . The groove group  26  includes long grooves  261  and short grooves  262 , which are grooves of multiple types (two types in the present embodiment) with different extension lengths. In the example illustrated in  FIG.  11   , the groove group  26  has four long grooves  261  and four short grooves  262  formed alternately on the outer surface of the protrusion  22  of the inner housing  2 E at a 45 degree pitch around the axis CL 22 . 
     The long grooves  261  extend from the base part of the cylindrical part  23  through the shoulder  22   b  of the protrusion  22  to the cylindrical part  22   a  and extend in the direction away from the opening  34  in the radial direction. The long grooves  261  are narrow grooves recessed inward from the outer surface of the protrusion  22 . Meanwhile, the short grooves  262  extend from the base part of the cylindrical part  23  to the shoulder  22   b  of the protrusion and extend in the direction away from the opening  34  in the radial direction. The short grooves  262  are narrow grooves recessed inward from the outer surface of the protrusion  22 . The short grooves  262  are shorter than the long grooves  261  and do not extend to reach the cylindrical part  22   a.    
     As illustrated in  FIG.  12   , the valve structure BK 5  and the valve structure BK use the same cover  3 . That is, the cover  3  and the protrusion  22  are in close contact with each other in the natural state if the long grooves  261  and the short grooves  262  are absent. The distance between the end of the cover  3  on the side far from the opening  34  and the opening  34  of each long groove  261  is different from that for each short groove  262 . In the natural state, the end of each long groove  261  on the side far from the cylindrical part  23  is covered with the cover  3  and does not communicate with the air chamber V. Similarly, the end of each short groove  262  on the side far from the cylindrical part  23  does not communicate with the air chamber V. That is, communication between the groove group  26  and air chamber V is regulated. 
     Suppose that the cover  3  is pressed in contact with the conchal cavity Eb and the air chamber V is compressed and deformed when the earplug  91 E is fitted into the conchal cavity Eb. In the above case, if the degree of deformation is small, the air chamber V communicates with the long grooves  261  first. Each long groove  261  functions as an air passage fe allowing the air chamber V and the outer space Vg to communicate. The compressed air in the air chamber V is discharged to the outside through the long grooves  261  serving as the air passage fe. Since the long grooves  261  have a small cross-sectional area, a large resistance occurs for the ventilation between the air chamber V and the outer space Vg. Therefore, even if the cover  3  is deformed and the air passage fe is first established, the pressurized air in the air chamber V is not discharged from the long grooves  261  to the outer space Vg at once, but is discharged over time. Therefore, the air chamber V shrinks gradually and elastically. 
     Meanwhile, when the deformation of the cover  3  is large, the air chamber V communicates not only with the long grooves  261  but also with the short grooves  262 . Each short groove  262  functions as an air passage ff allowing the air chamber V and the outer space Vg to communicate. Therefore, the greatly compressed air in the air chamber V due to the large collapse deformation of the cover  3  passes through the air passage fe and the air passage ff of each long groove  261  and each short groove  262  and is discharged to the outer space Vg. Thus, if the collapse deformation of the cover  3  is large, an amount of pressurized air in the air chamber V in accordance with the collapse deformation can be properly discharged. Therefore, the elastic repulsive force of the air chamber V imparted to the conchal cavity Eb by the cover  3  is not applied to the head with excessive force. That is, the elastic repulsive force of the cover  3  is stably applied to the conchal cavity Eb regardless of the amount of collapse deformation of the cover  3  which collapses in contact with the conchal cavity Eb when the earplug  91 E is mounted on the auricle E. Therefore, it is possible to obtain a better wearing sensation. 
     An ear mount is not limited to an earplug. The ear mount may be what is referred to as an earplug type earphone or a hearing aid that houses a speaker unit inside the body part  911  and emits sound into the ear canal through the cylindrical part  23 . 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.