Abstract:
A hearing aid attachment system includes a positioning tool and an interconnection unit. An upper surface of the interconnection unit has a second shape that matches a corresponding first shape of a cavity in the lower surface of the positioning tool so that the upper surface fits into the cavity with a second front surface of the positioning tool against and radially outside the front side of the interconnection unit, with the connection portion of the positioning tool connected to the connecting portion of the interconnection unit. The positioning tool is further configured to be removable from the interconnection unit without removing the interconnection unit from the skin.

Description:
[0001]    This application is a continuation of co-pending U.S. patent application Ser. No. 14/870,438, filed Sep. 30, 2015, which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a hearing aid system that includes a positioning tool. 
       BACKGROUND ART 
       [0003]    A hearing aid may be attached behind the ear through an adhesive interconnection unit as described in for example US2015063616. The interconnection unit is adhesively attached to the skin behind the ear and the hearing aid can then be connected to the interconnection unit since there is a coupling between the hearing aid and the interconnection unit. The coupling allows the hearing aid to be snapped on and off from the interconnection unit without removing the interconnection unit from the skin. The interconnection unit can be changed at intervals suitable for the skin, for example once a week. 
         [0004]    When adhering an interconnection unit to the skin behind the ear it is very important to find the right position before pressing the interconnection unit towards the skin to adhere it since it is both a stress to the skin to remove it from the skin and also the adhesive properties of most adhesives are reduced after removing it from the skin so that when trying to attach the same adhesive surface again would this would result in a poorer adhesion to the skin. 
         [0005]    The interconnection unit should be adhered to hair free skin behind the ear since adhesion to a hairy area is usually poor. It is therefore important that the interconnection unit is not placed too far to the rear behind the ear since it would then be at least partly adhered to the hair baring area and the adhesion would be very poor. It is however also important that the interconnection unit does not touch the outer ear since this may be uncomfortable. The interconnection unit is usually quite flat so it will go under the main part of the outer ear so if it would be placed too close to the outer ear it would touch the outer ear in the outer ear fold behind the outer ear. 
         [0006]    The position of the interconnection unit on the skin surface behind the ear decides also the position of the hearing aid in relation to the outer ear when the hearing aid is connected to the interconnection unit. The hearing aid must also not touch the outer ear since this may be uncomfortable and since this may also cause acoustic feedback. It is therefore very important that the interconnection unit is adhered to the skin behind the ear in a correct position so that the hearing aid does not touch the outer ear when the hearing aid is connected to the interconnection unit. Depending on the individual size and shape of the outer ear, it may be either the interconnection unit or the hearing aid that would be the most likely part of the hearing aid system to touch the outer ear. 
         [0007]    The hairless skin area behind the ear is quite limited in size so the precision in the positioning of the interconnection unit has to be very accurate. At the same time it is difficult for the user to see behind the ear when adhering the interconnection unit even if a mirror is used. 
         [0008]    The optimal position of the hearing aid and interconnection unit is close to the ear, but without any of the interconnection unit or the hearing aid touching the outer ear. It is a challenge to try to position the interconnection with the current hearing aid systems. There is a need for a more effective and user friendly adhesive hearing aid system that is reliable and does not have the drawbacks discussed above. 
       SUMMARY 
       [0009]    The present invention provides an effective solution to the above-outlined problems of hearing aid systems that includes an adhesively attachable interconnection unit to connect the hearing aid to the skin behind the ear. More particularly, the hearing aid system of the present invention includes a positioning tool that can assist the user to find the right position. This hearing aid system with a positioning tool is a unique and important step forward to make this type of hearing aid systems more applicable and user friendly. 
         [0010]    The hearing aid system of the present invention has an interconnection unit that has a first side with a first connection portion that has a circular geometry, and this circular geometry has a center axis. The first connection portion is positioned non-centrically on the first side and towards a rear end of the interconnection unit which is opposite to a front end of the interconnection unit. Opposite to the first side, the interconnection unit has also a second side with an adhesive surface. 
         [0011]    The hearing aid system also includes a hearing aid having a third front surface and a second connection portion. The first connection portion can be removably connected to the second connection portion and the circular geometry of the first connection portion allows the hearing aid to be rotated around the center axis in relation to the interconnection unit when the hearing aid is connected to the interconnection unit. There is of course a friction in this rotation so that the hearing aid does not rotate freely, however the possibility to turn the hearing aid by hand in relation to the interconnection unit is valuable in fine tuning the position and orientation of the hearing aid and its microphones. 
         [0012]    The positioning tool has a seat so that the interconnection unit can be placed in this seat and the interconnection unit can be connected to the positioning tool with the first side of the interconnection unit facing the positioning tool when the interconnection unit is connected to the positioning tool. The interconnection unit can be removably connected to the positioning tool. The positioning tool has a first front surface and also a grip to hold it with the fingers. 
         [0013]    Furthermore, the positioning tool is designed so that the front end of the interconnection unit is oriented in the same direction as the first front surface when the interconnection unit is located in the seat of the positioning tool. 
         [0014]    To use the components of the present invention, the interconnection unit is first placed in the positioning tool, and then by sensing when the positioning tool touches the outer ear, the correct position for the interconnection unit behind the outer ear is found. By pressing the positioning tool, the adhesive surface of the interconnection unit is pressed against the skin so that it adheres properly. The positioning tool is removed from the interconnection unit and then the hearing aid can be connected to the interconnection unit and the position of the hearing aid can be fine-tuned by turning it in relation to the interconnection unit. 
         [0015]    Furthermore, the positioning tool may have a specific holder portion to which the first connection portion can be removably connected so that the first connection portion is in connection with the holder portion when the interconnection unit is located in the seat of the positioning tool. In this way, the first connection portion can be used both for connecting to the hearing aid and for connecting to the positioning tool. 
         [0016]    In a preferred embodiment of the hearing aid system of the present invention, the distance from the first front surface of the positioning tool to the center axis when the interconnection unit is located in the seat of the positioning tool is greater than the distance from the third front surface of the hearing aid to the center axis when the first connection portion is connected to the second connection portion. In this way, a certain distance is ensured between the outer ear and the hearing aid unit as long as the positioning tool has been used to sense the right position behind the outer ear when adhering the interconnection unit to the skin behind the outer ear. The position of the hearing aid in relation to the ear is mainly be determined by the position of the interconnection unit on the skin behind the outer ear. In a preferred embodiment of the hearing aid system of the present invention, the positioning tool has a second front surface that is located at the same side of the positioning tool as the first front surface. The second front surface is at least partly following the curvature of the front end of the interconnection unit (this curvature is best seen from the axial direction when the interconnection unit is placed in the positioning tool), and the second front surface of the positioning tool is more distant from the center axis than the front end of the interconnection unit when the interconnection unit is located in the seat of the positioning tool. In this way, a certain distance is ensured between the outer ear and the interconnection unit when using the positioning tool to sense the right position behind the outer ear when adhering the interconnection unit to the skin behind the ear. 
         [0017]    The hearing aid may specifically be a bone conduction hearing aid generating vibrations that are transmitted to the interconnection unit via the second connection portion. This type of device may specifically benefit from an efficient adhesive fixation and since the device includes a vibrator, it is also quite a big and heavy hearing aid so it is especially important to position it correctly. The bone conduction hearing aid may be an be an ear level bone conduction device where the microphones are mounted to the housing of the hearing aid and to avoid acoustic feedback there is a suspension system between the vibrator and the hearing aid housing to isolate the vibrations from the vibrator from the housing and the microphones to avoid acoustic feedback. This suspension system would be disturbed if a force is applied to the hearing aid housing and this would cause acoustic feedback and it is therefore very important that the hearing aid does not touch the outer ear since this would cause acoustic feedback. 
         [0018]    The interconnection unit and the positioning tool may specifically be designed so that the holder portion is a female connection and that the second connection portion has a male portion that can be entered into the female holder portion to connect the interconnection unit to the positioning tool. This design results in a very efficient and practical design of the arrangement. 
         [0019]    In a preferred embodiment of the hearing aid system of the present invention, the holder portion is flexible to connect to the first connection portion. This may be an important feature since the connection force between the positioning tool and the interconnection unit may not have to be as strong as the connection force between the hearing aid and the interconnection. The connection force between the positioning tool and the interconnection unit may only have to ensure that the interconnection unit does not fall off from the positioning tool when handling the components and attaching the interconnection unit to the skin and the positioning tool should then be easy to disconnect from the interconnection unit once the interconnection unit has been adhered to the skin. The connection force between the hearing aid and the interconnection unit should however preferably be stronger since it should be able to carry the weight of the hearing aid that may include, for example, batteries, and the hearing aid must not fall off due to physical exercise by the user. 
         [0020]    In a preferred embodiment of the hearing aid system of the present invention, the positioning tool includes a flexible rubber material which may be an efficient way of creating a suitable positioning tool and specifically a suitable connection force of the holder portion. 
         [0021]    In a preferred embodiment of the hearing aid system of the present invention, the positioning tool includes a rear edge opposite to the second front surface and where the rear edge is a shaving line template edge positioned at a distance from the center axis that is greater than the distance from the center axis to the rear end of the interconnection unit when the interconnection unit is connected to the positioning tool. In this way, the positioning tool can also be used as a template to mark what area behind the ear that needs to be hairless to ensure that the interconnection unit is attached to hairless skin. The positioning tool used as a template may show which hair baring area needs to be shaved to become hairless. 
         [0022]    In a preferred embodiment of the hearing aid system, the hearing aid component is attached to a skin portion behind the ear of the user and the positioning has a front surface and a lower portion disposed below the grip portion. The lower portion has a cavity with a first shape and the cavity has a connecting portion inside. The interconnection unit has a lower adhesive surface and an upwardly extending connection portion and a second shape similar to the first shape so that the interconnection unit fits well into the cavity. The interconnection unit is placed in the cavity with the lower adhesive surface facing away from the positioning tool and the connection portion of the interconnection unit is connected to the connection portion of the positioning tool. A side of the positioning tool is abutting a portion of the ear and the positioning tool, with the interconnection unit disposed therein, is moved towards the skin portion behind the ear while permitting the front surface on the side of the positioning tool to slide along the outer tip portion of the ear to guide the positioning tool. The lower adhesive surface is adhered to the skin portion behind the ear of the user and then the positioning tool is removed from the interconnection unit without removing the interconnection unit from the skin portion, and then the positioning tool is removed from the interconnection unit. The positioning tool may have an outwardly extending lip portion at a bottom of the positioning tool so that the lip portion can slide along a rear surface of the ear. The lip portion step may abut against a skin fold defined between the ear and the skin portion. 
         [0023]    The hearing aid unit has a connection portion that can be connected to the connection portion of the interconnection unit, and the hearing aid unit can be turned the relative to the interconnection unit while the hearing aid unit is connected to the interconnection unit. The hearing aid unit can be tilted relative to the interconnection unit to disconnect the hearing aid unit from the interconnection unit, preferably this is done while at the same time pressing the hearing aid unit towards the interconnection to ensure that the interconnection unit is not disconnected from the skin. The concept includes placing the interconnection unit and the hearing aid unit behind the ear so that neither the interconnection unit nor the hearing aid unit touches the ear. An alternative is also that the hearing aid unit can be connected to the positioning tool prior to connecting the hearing aid unit to the interconnection unit. 
         [0024]    As described above, the hearing aid system of the present invention includes a unique combination of solutions and provides new solutions and several advantages to meet complex user requirements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a perspective view of the positioning tool and the interconnection unit of the hearing aid system of the present invention. 
           [0026]      FIG. 2  is a perspective view of the embodiment shown in  FIG. 1 , shown from another angle. 
           [0027]      FIG. 3  is a perspective view of the embodiment shown in  FIG. 2 , where the interconnection unit has been seated in the positioning tool. 
           [0028]      FIG. 4  is a perspective side view of the embodiment shown in  FIG. 3 , where the positioning tool and the interconnection unit is positioned behind the outer ear to adhere the interconnection unit to the skin in a correct position behind the outer. The ear is seen from a caudal view of the user. 
           [0029]      FIG. 5  is a perspective side view of the hearing aid and the interconnection unit of the hearing aid system of the present invention where the hearing aid is connected to the interconnection unit positioned in a correct position behind the outer ear seen from a caudal view of the user. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]      FIG. 1  shows a perspective view of a positioning tool  100  and an interconnection unit  110  of the hearing aid system of the present invention. The positioning tool  100  has a first front surface  102  and an outwardly extending lip  130 , disposed below the first front surface  102 . The lip  130  has a second front surface  103 . The positioning tool  100  has a grip portion  101 . Preferably, the positioning tool  100  has an opening  134 , including a central axis  116 , extending from a holder portion  105  (best shown in  FIG. 2 ) disposed inside the positioning tool to an upper end  136  of the positioning tool  100 . The positioning tool  100  has a triangular-shaped cavity  138  (best shown in  FIG. 2 ) defined therein at a bottom  140  of the tool  100 . As described in detail below, the cavity  138  is adapted to receive the upper part of the interconnection unit  110 , preferably, in a relatively tight fit so that the interconnection unit  110  may be inserted into the cavity  138  and held inside thereof by tool  100 . The shape of cavity  138  is thus formed to substantially match the shape of the upper side of interconnection unit  110  so that peripheral edges  170  around unit  110  match and fit inside a peripheral rim  120  of unit  100  that surrounds cavity  138 . The unit  110  is held to unit  100  by a connection portion  106  and holder portion  105 , as described in detail below. 
         [0031]    The interconnection unit  110  has the upwardly extending first connection portion  106  that has a circular geometry with a center axis  116 . The first front surface  102  is located along the same side of the positioning tool  100  as the second front surface  103 . The interconnection unit  110  has a first upper side  107  and a second lower side  108  (best shown in  FIGS. 2-3 ) opposite to the first side  107 . The interconnection unit  110  has holes  119  defined therein on the upper side  107  for moisture transportation. Preferably, the first connection portion  106  of the interconnection unit  110  is positioned closer to a rear end  122  opposite to a front side  118 . 
         [0032]      FIG. 2  is a perspective view of positioning tool  100  and interconnection unit  110 , as shown in  FIG. 1  but shown from a different angle. The second side  108  of the interconnection unit  110  is an adhesive surface so that the interconnection unit  110  can be adhesively attached to the skin behind the ear of a user (see also  FIGS. 4 and 5 ). As indicated above, the first connection portion  106  can be removably connected to the holder portion  105  of the positioning tool  100  by pressing the first connection portion  106  into the holder portion  105  until they are connected together by for example friction forces so that the interconnection unit  110  can be lifted up by the positioning tool  100  (see also  FIG. 3 ). Preferably, holder portion  105  is flexible to connect in a gentle way to the connection portion  106 . The positioning tool  100  has a seat  104 , that forms the bottom of cavity  138 , with rim  120  that has a shape that allows the front side  118  of the interconnection unit  110  to be oriented in the same direction (i.e. to the same side of the center axis  116 ) as the second front surface  103  when the first connection portion  106  is connected to the holder portion  105  and the interconnection unit  110  is seated in the seat  104  of the positioning tool  100 . Another feature is that the connection force between first connection portion  106  and holder portion  105  may not be greater than the connection force that may be established between the adhesive surface  108  and the skin (see  FIG. 4 ) so that tool  100  may simply be pulled off from interconnection unit  110  while unit  110  remains adhered to the skin. 
         [0033]    The first front surface  102  may be located closer to the center axis  116  than the second front surface  103  when the positioning tool  100  is connected to the interconnection unit  110  since the interconnection unit  110  may be attached to the skin on the head under an outer ear (see also  FIG. 4  and  FIG. 5 ) and it is therefore important that the positioning tool  100  is adapted to this. 
         [0034]      FIG. 3  is a perspective view of positioning tool  100  and interconnection unit  110 , as shown in  FIG. 2 , but where the interconnection unit  110  is connected to the positioning tool  100 . The second front surface  103  (best shown in  FIG. 1 ) is further away from the center axis  116  than the front side  118  of the interconnection unit  110  when the interconnection unit  110  has been connected to the positioning tool  100  due to the rim  120 . An important feature of the present invention is that the adhesive surface of side  108  extends beyond or is aligned with rim  120  when interconnection unit  110  is fully inserted into cavity  138  so that the adhesive surface of side  108  may conveniently be adhered to a skin surface (see  FIG. 4 ) by urging side  108  against the skin while unit  110  is disposed inside tool  100 . 
         [0035]      FIG. 4  is a perspective view of positioning tool  100  and interconnection unit  110 , as shown in  FIG. 3 , but shown when the adhesive surface of second side  108  (best shown in  FIG. 5 ) is attached to a skin  112  on the head behind an outer ear  111  of a user. The skin fold  121  between the skin  112  on the head and the outer ear  111  is also marked. By sensing when either the first front surface  102  is touching and rear outer tip  150  of the outer ear  111  or when the second front surface  103  is touching the skin fold  121  disposed at a bottom of outer ear  111  where outer ear  111  meets skin  112  or when surface  103  touches a rear skin surface  142  (that extends between skin fold  121  and rear outer tip  150 ) below rear outer tip  150  of the outer ear  111 , the positioning tool  100  helps the user to correctly position and attach the adhesive interconnection unit  110  on the skin in the desired position behind the outer ear  111 . In the correct position behind the outer ear  111 , the interconnection unit  110  must not touch the skin fold  121  or the outer ear  111  since this may cause discomfort. In the correct position of the interconnection unit  110  behind the outer ear  111  the hearing aid  113  (see  FIG. 5 ) will also not touch the outer ear. 
         [0036]    The user holds the positioning tool  100  with the connected interconnection unit  110  disposed inside cavity  138  and held therein by connection portion  106  and holder portion  105  and then finds the correct position behind the outer ear  111  by sensing when the positioning tool  100  touches either the skin fold  121  or the outer ear  111 , and then the interconnection unit  110  is pressed against the skin  112  with the positioning tool  100  so that the adhesive surface of side  108  of interconnection unit  110  is adhesively attached to the skin  112 . The seat  104  (see  FIG. 2 ) is in contact with at least part of the first side  107  (see  FIG. 1 ) of the interconnection unit  110  so that the interconnection unit  110  can be pressed against the skin  112  using the positioning tool  100  to properly adhere the adhesive surface of the second side  108  (not shown} to the skin  112 . 
         [0037]    The positioning tool  100  is then removed from the interconnection unit  110  so that the hearing aid  113  (see  FIG. 5 ) can be attached to the interconnection unit  110 . If the positioning tool is placed on skin  112 , as shown in  FIG. 4 , it is also possible to use a rear edge  124  of the positioning tool  100  that is not facing the outer ear  111  as a template to draw a line with a pencil (not shown) on the skin  112  or on the hair (no shown) to mark the area of the skin  112  that needs to be hairless to be able to securely attach the adhesive second side  108  to hairless skin. In case the pencil mark would enter the hair baring area of the skin  112 , the pencil mark would show the need for shaving of some hair behind the outer ear  111 . In this way, the positioning tool  100  may also be used as a template for required shaving in case the naturally hairless area behind the outer ear  111  is too small to accommodate the interconnection unit  110  properly on an individual user. 
         [0038]      FIG. 5  is a perspective side view of the hearing aid  113 , which is a bone conduction device transmitting sound to the inner ear with vibrations through the bone (not shown) when it is connected to the interconnection unit  110  (this is the same interconnection unit  110  as shown in  FIG. 4 ) in its correct position on the skin  112 . The hearing aid is an ear level bone conduction device where the microphones (not shown) are mounted to the housing  114  of the hearing aid  113 , and to avoid acoustic feedback there is a suspension system (not shown) between the vibrator (not shown) and the hearing aid housing  114  to isolate the vibrations from the vibrator from the housing and the microphones to avoid acoustic feedback. The suspension system (not shown), the microphones (not shown) and the vibrator (not shown) are all located inside the hearing aid housing  114 . The hearing aid  113  is connected to the first connection portion  106  of the interconnection unit  110 . 
         [0039]    The hearing aid  113  has a second connection portion  160  that allows it to be removably connected to the first connection portion  106 . The vibrator (not shown) is firmly connected to the second connection portion  160  to transmit bone conduction vibrations to the user via the interconnection unit  110 . The hearing aid  113  may be connected and disconnected several times from the interconnection unit  110  without removing the interconnection unit  110  from the skin  112 . The hearing aid  113  can be turned around the center axis  116  in relation to the interconnection unit  110  since it can be turned around the circular connection portion  106  and this is useful to be able to fine-tune the position and orientation of the hearing aid  113  behind the outer ear  111 . 
         [0040]    The second connection portion  160  and the first connection portion  106  is preferably designed so that by pressing the hearing aid towards the interconnection unit  110  on the head and titling the hearing aid  113 , the second connection portion  160  is disconnected from the first connection portion  106  and the hearing aid can be removed without removing the interconnection unit  110  from the skin  112 . The interconnection unit  110  may be changed at intervals suitable for the skin  112  and depending on the adhesion between the second side  108  and the skin  112 . 
         [0041]    The hearing aid  113  has a third front surface  117  that is facing the outer ear  111  when the hearing aid  113  is worn. The distance from the first front surface  102  (see  FIG. 4 ) to the center axis  116  (see  FIG. 4 ) when the positioning tool  100  is connected to the interconnection unit  110  is greater than the distance between the third front surface  117  and the center axis  116  when the hearing aid  113  is connected to the interconnection unit  110 . This is to ensure that the hearing aid  113  does not touch the outer ear  111  when it is connected to an interconnection unit  110  correctly positioned behind the outer ear  111 . 
         [0042]    The present invention offers unique new features since the interconnection unit  110  can be connected to both the positioning tool  100  and to the hearing aid  113 , and that the connection to the hearing aid  113  allows for some rotation and that the connection to the positioning tool  100  ensures that the front end  118  of the interconnection unit  110  is oriented in the same direction as the first front surface  102  to ensure that the hearing aid  113  does not touch the outer ear  111  once it is connected to the correctly positioned interconnection unit  110  on the user. This allows the positioning tool  100  to facilitate a correct position and orientation of the interconnection unit  110  when adhering it to the skin  112  and at the same time allowing fine tuning of the hearing aid  113  orientation by rotating it in relation to the interconnection unit  110  when it is worn on the head of a user. It was surprising to find out how valuable the present invention is by providing a significant improvement of adhesively attachable hearing aid systems. The big improvement offered by the present invention was unexpected and it certainly is a big step forward. The different design features interacted in a unique and user friendly way. 
         [0043]    With the new hearing aid system of the present invention, the new unique method offers a practical, efficient and user-friendly new hearing aid system that secures the quality of the treatment when it comes to avoiding the risk for acoustic feedback, improving the wearing comfort and making the hearing aid system straightforward and easy to use. 
         [0044]    To use the hearing aid system of the present invention, the positioning tool  100  is used with the interconnection unit  110  that is then used with the hearing aid  113 . The interconnection unit  110  is connected to the positioning tool  100  by placing the interconnection unit  110  in the seat  104  with the adhesive second side  108  facing away from the positioning tool  100 , and the front end  118  of the interconnection unit  110  is oriented towards the same side of the positioning tool  100  as the first front surface  102 . 
         [0045]    The connection force between the interconnection unit  110  and the positioning tool  100  may be quite low and just have to ensure that the relatively light (preferably with a weight less than 2 gram) interconnection unit  110  does not fall off the positioning tool  100  during handling i.e. when the user places the positioning tool  100  with the interconnection unit  110  disposed or held inside the positioning tool  100 , as described below. Alternatively it would also be possible insert an elongate object (not shown) through the opening  134  to keep the interconnection unit  110  in place on the skin  112  while removing the positioning tool  100  from the interconnection unit  110 , and this would enable a higher connection force between the interconnection unit  110  and the positioning tool  100  to be chosen. 
         [0046]    The interconnection unit  110  is thus held with the positioning tool  100  at the surface of the skin  112  behind the outer ear  111  so that the adhesive second surface  108  is held slightly above the surface of the skin  112  or in very light contact with the skin  112  so that the adhesive second side  108  can be moved sideways along the surface of the skin  112  without fixating side  108  to the skin  112 . 
         [0047]    The positioning tool  100 , with the interconnection unit  110  disposed therein, is moved behind the ear  112  towards the outer ear  111  to find a position behind the outer ear  111  where the second front surface  102  lightly touches the rear outer tip  150  by the user sensing when the first front surface  102  of the positioning tool  100  is in contact with the rear outer tip  150 . Depending upon the exact configuration of the back side of outer ear  111 , it is also possible that surface  103  abuts skin fold  121  or the rear surface  142  prior to first front surface  102  abutting the rear outer tip  150 . It is important that the user determines when either first front surface  102  touches rear outer tip  150  of outer ear  111  or when second front surface  103  touches skin fold  121  or the rear surface  142 . Whatever of the above that positioning tool  100  abuts first helps the user to correctly position and attach the adhesive interconnection unit  110  on the skin  112  in the desired position behind the outer ear  111 . 
         [0048]    The adhesive second side  108  of the interconnection unit  110  is then attached to the skin  112  by pressing the second side  108  against the skin  112  i.e. by pressing the positioning tool  100  against the interconnection unit  110 . Thereafter, the positioning tool  100  is removed from the interconnection unit  110  without removing the interconnection unit  110  from the skin  112 , and this may be done by pulling the positioning tool  100  straight off from the interconnection unit  110  so that connection portion  106  is disengaged from holder portion  105 . 
         [0049]    The hearing aid  113  with the second connection portion  160  is now connected to the first connection portion  106  of the interconnection unit  110  by snapping it on to the first connection portion  106 . The hearing aid  113  has a third front surface  117  that is less distant to the center axis  116  when the hearing aid  113  connected to the interconnection unit  110  than the first front surface  102  of the positioning tool  100  when the interconnection unit  110  is connected to the positioning tool  100 , and since the interconnection unit  110  was adhered to the skin  112  using the positioning tool  100  there will be a gap between the third front surface  117  and the rear outer tip  150 , i.e. the hearing aid  113  will not touch the outer ear  111 . 
         [0050]    The second connection portion  106  can be turned in relation to the first connection  105  around the center axis so that the orientation of the hearing aid  113  in relation to the outer ear  111  may be adjusted somewhat without disconnecting the interconnection unit  110  from the skin  112 . The hearing aid  113  can now be used to stimulate the hearing organ (not shown) of the user. The hearing aid  113  may, for example, be a bone conduction hearing aid that transmits bone conduction vibrations via the interconnection unit  110  to the user. 
         [0051]    The connection force between the second connection portion  160  and the first connection portion  106  may be much higher than the connection force between the interconnection unit  110  and the positioning tool  100  because the hearing aid  113  must not fall off easily from the user. 
         [0052]    The hearing aid  113  can be removed from the interconnection unit  110  without removing the interconnection unit  110  from the skin  112 . The first connection portion  106  and the second connection portion  160  are designed to form a snap coupling so that the hearing aid  113  can be disconnected from the interconnection unit  110  by tilting the hearing aid  113  in relation to the interconnection unit  110  and at the same time pressing the hearing aid  113  towards the interconnection unit  110  to ensure that the interconnection unit  110  is not removed from the skin  112  when disconnecting the hearing aid  113  from the interconnection unit  110 . The hearing aid  113  can be connected and disconnected several times from the interconnection unit  110  without removing the interconnection unit  110  from the skin  112 . 
         [0053]    Preferably, the positioning tool  100  has the second front surface  103  located on the same side of the positioning tool  100  as the first front surface  102 . Furthermore, the interconnection unit  110  has the front end  118  located at a shorter distance from the center axis  116  than the second front surface  103  when the interconnection unit  110  is positioned in the seat  104  of the positioning tool  100 . The positioning tool  100 , with the interconnection unit  110  disposed therein, is with this method moved behind the outer ear  111  as described above to attach the interconnection unit  110  in a correct position behind the outer ear  111 . In this way, it is ensured that neither the interconnection unit nor the hearing aid, when they are finally and properly mounted behind outer ear  111 , touches the outer ear to cause discomfort, acoustic feedback or other problems once the hearing aid  113  is attached to the interconnection unit  110 . 
         [0054]    The hearing aid system of the present invention may also be designed so that the interconnection unit  110  may be connected to both the hearing aid  113  and the positioning tool  100  at the same time. Either the hearing aid  113  may be connected to the interconnection unit  110  first and then the interconnection unit  110  is placed in the seat  104  of the positioning tool  100 , or alternatively the interconnection unit  110  is positioned in the seat  104  of the positioning tool  100  first and then the hearing aid  113  is connected to the interconnection unit  110 . The positioning tool  100  may then be removed from the interconnection unit  110  so that the hearing aid  113  and the interconnection unit  110  can be used without the positioning tool  100 . It is also possible to design the bottom cavity  138  of the positioning tool  100  so that is matches a shape of the top of the hearing aid  113  so that the positioning tool  100  may be used to together place the hearing aid  113 , with the interconnection unit  110  attached thereto, onto the skin portion behind ear  111 . In other words, the hearing aid  113  is snapped onto the interconnection unit  110  and the positioning tool  100  is then mounted on top of the hearing aid  113  before the tool  100  is used to guide, such as by abutting the outer tip  150 , the user to place the interconnection unit  110  behind the ear  111  in a manner that is similar to the manner described above i.e. by adhering a bottom surface  108  of unit  110  to the bare skin area behind the ear  111 . 
         [0055]    For all of the above embodiments several alternative designs and combinations are possible and the invention is not limited to the preferred embodiments presented above. While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims.