Abstract:
A hearing aid configuration and an associated method provide wireless transmission of data between a hearing aid and an external unit. The external unit, for example a programming device, is worn with a lanyard around the neck of a hearing aid user. The configuration additionally contains at least one second antenna disposed in the lanyard and at least one third antenna arranged in the lanyard which is connected by an electric series circuit to the second antenna. The advantage of this is that the lanyard can be made long enough to be comfortable to wear and a sufficiently high receive signal of the wireless data transmission is still guaranteed in the external unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority, under 35 U.S.C. §119(e), of provisional application No. 61/167,203, filed Apr. 7, 2009; this application also claims the priority, under 35 U.S.C. §119, of German application DE 10 2009 016 661.0, filed Apr. 7, 2009; the prior applications are herewith incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a hearing aid configuration with a lanyard and a method for wireless transmission of data between the hearing aid and an external unit. 
     For wireless programming of hearing aids with inductive antennas, for example with wound coils on ferrite cores, the receive level is low at a programming device since the transmit power of the hearing aid is restricted and the hearing aid antennas are configured to be small. The reason for this is the limited factory capacity and the lack of space available in hearing aids. 
     As a consequence of the low receive level the signal-to-noise ratio is low, which imposes heavy restrictions on the maximum data rate between the hearing aid and the programming device. To improve this situation a precise alignment of the antennas to each other is required. In such cases the signal-to noise ratio is adversely affected by the hearing aid wearer turning his head. 
     By contrast the transmit level in the programming device is high since there is enough space available for a battery with a large storage capacity. As a result of the high transmit level the signal-to-noise ratio at the location of the hearing aid is high, making a high maximum data rate between the programming device and the hearing aid possible. A precise alignment of the antennas to each other is not absolutely necessary. 
     Wireless programming of hearing aids is consequently very unsymmetrical. Data transmission is fast and secure when the programming device is sending data to the hearing aid but is slow and insecure when the programming device is receiving data from a hearing aid. It would thus be advantageous to find a possibility of enhancing the receive signal in the programming device. 
     A known solution lies in connecting the programming device to a neck strap, also referred to as a lanyard. For the highest possible receive signals the length of the lanyard must be as short as possible in order to keep the distance between the hearing aid and the programming device small. The disadvantage of this is that hearing aid users often do not want to wear short lanyards since these are uncomfortable to wear. The negative effect of turning one&#39;s head during a programming process is still present even with short lanyards. 
     Another solution is described in published European patent application EP 1 981 176 A1. A multi-strand of loop antenna is integrated into the lanyard. In addition a loop antenna is balanced with a capacitor in series resonance in order to increase the signal strength. The disadvantage of this is that the loop inductance of the loose lanyard varies greatly during use making resonance balancing difficult. In addition for safety reasons, to avoid the risk of strangulation, what are referred to as release or separation elements are integrated into the lanyard which release the lanyard when it is subjected to a predetermined force. Since the loop antenna must also be routed through the release element, contact problems often occur which restrict functional capabilities. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide a hearing aid configuration with a lanyard with an integrated antenna and an associated method for wireless transmission of data which overcome the above-mentioned disadvantages of the prior art methods and devices of this general type. 
     The invention recites a hearing aid configuration for wireless transmission of data between a hearing aid and an external unit which is worn on the lanyard around the neck of the hearing aid user. The configuration further contains at least one second antenna disposed in the lanyard and at least one third antenna arranged in the lanyard which is connected to the second antenna by of an electric series circuit. The advantage of this is that the lanyard can be embodied long enough to be comfortable to wear and that despite this a sufficiently high receive signal of wireless data transmission still arrives at the external unit. 
     In a development of the invention the second and third antenna can each be an inductive antenna. This ensures a secure near field data transmission with low power requirement. 
     In a further embodiment the data from the hearing aid can be coupled in in the second antenna and the data coupled in in the second antenna can be coupled in from the third antenna into the external unit. This offers the advantage of an additional indirect transmission path between the hearing aid and the external unit. 
     Furthermore the configuration can contain at least one first antenna arranged in a hearing aid and at least one fourth antenna arranged in the external unit. This makes wireless data exchange possible. 
     Advantageously the external unit can be a hearing aid programming device. 
     In addition the second antenna can be arranged in the vicinity of the hearing aid and the third antenna can be arranged in the vicinity of the external unit. This improves data transmission. 
     In a further embodiment the at least one second antenna can be arranged such that, when the hearing aid wearer turns their head, the first antenna approaches the second antenna. This offers the advantage of turning the head having less of an effect on the power received in the external unit. 
     The configuration can also contain two diodes oriented in different directions which are arranged in parallel to the third antenna. This enables statutory requirements for radio transmission to be adhered to. 
     In a further development the configuration can contain at least one first and one second capacitor, which are arranged in series to the second and third antenna. Advantageously resonant circuits can be formed by these capacitors. 
     The invention specifies a method for wireless transmission of data between a hearing aid and an external unit. The external unit is typically a hearing aid programming device. The method includes the steps of emitting the data by at least one first antenna arranged in the hearing aid, receiving the data output by the first antenna by at least one second antenna, emitting the data received by the second antenna by at least one third antenna connected electrically to the first antenna and receiving the data emitted by the first and third antenna by at least one fourth antenna arranged in the external unit. This offers the advantage of undisturbed data transmission between the hearing aid and the external unit. 
     In a development of the method the at least one second and the at least one third antenna can be arranged in a lanyard. 
     In a further embodiment the second antenna can be arranged in the vicinity of the hearing aid and a third antenna in the vicinity of the external unit. 
     Furthermore the at least one second antenna can be arranged such that, if the wearer of the hearing aid turns their head, the first antenna is approached by the second antenna. 
     Advantageously the antennas can be inductive antennas. 
     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a hearing aid configuration with a lanyard with an integrated antenna and an associated method for wireless transmission of data, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  is an illustration of a hearing aid configuration with a lanyard according to the prior art; 
         FIG. 2  is an illustration of the hearing aid configuration with two inductive antennas in the lanyard according to the invention; 
         FIG. 3  is an illustration of the inventive hearing aid configuration with three inductive antennas in the lanyard; 
         FIG. 4  is a diagram with comparison measurements; and 
         FIG. 5  is an illustration of the inventive hearing aid configuration with a loop antenna in the lanyard. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the figures of the drawing in detail and first, particularly, to  FIG. 1  thereof, there is shown the principle of wireless data exchange  12  between a hearing aid  1  and a programming device  2  in accordance with the prior art. To change the settings of the hearing aid  1  data to be transmitted is exchanged with the programming device  2 . Since, because of the limited signal power of the hearing aid  1 , a maximum distance cannot be exceeded to the programming device  2 , a hearing aid wearer—only his head  4  is shown in FIG.  1 —wears the programming device  2  during the programming process on a lanyard  3  around his neck. The data transmission  12  preferably occurs inductively with the help of an inductive first antenna  11  in the hearing aid  1  and an inductive fourth antenna  21  in the programming device  2 . The antennas  11 ,  21  are preferably embodied as wire coils wound onto a ferrite core. 
     To avoid strangulation during a high tensile load on the lanyard  3  a safety release element  36  is arranged in the lanyard  3 , which opens the lanyard  3  when it is subjected to a predetermined force. If the hearing aid wearer turns his head to the right by an angle of rotation  41 , the signal-to-noise ratio deteriorates for the hearing aid  1  worn on the right at the location of the fourth antenna  21  since the distance from the programming device  2  and the shadowing by the head  4  increases. 
     To reduce the influence of the wearer turning his head and for generally improving the signal-to-noise ratio a configuration in accordance with  FIGS. 2 and 3  is selected.  FIG. 2  shows the head  4  of a hearing aid wearer with a left-hand and a right-hand hearing aid  1 . For programming the hearing aid  1  the hearing aid user wears the programming device  2  attached to the lanyard  3  worn around his neck. To guard against strangulation the lanyard  3  includes a safety release element  36  which opens up when the lanyard  3  is subjected to a predetermined force. 
     Arranged in the two hearing aids  1  for wireless data exchange  12  with the programming device  2  is the first inductive antenna  11  in the form of a transceiver coil. The programming device  2  has a fourth inductive antenna  21  in the form of a transceiver coil as the communication partner. During data exchange  12  data is exchanged inductively between the hearing aid  1  and the programming device  2  on a direct signal path  12 . 
     To improve the signal power an indirect signal transmission path  37 ,  38  is also used. A second inductive antenna  31  and a third inductive antenna  32  are incorporated into the lanyard  3  for this purpose. The antennas  31 ,  32  are preferably wire coils wound onto a ferrite core. The second and the third antenna  31 ,  32  are connected by an electrical series circuit with the aid of the electrical connecting line  39 . The third inductive antenna  31  is arranged in the vicinity of the fourth inductive antenna  21  of the programming device  2  and the second inductive antenna  31  is arranged in the neck area of the hearing aid wearer in the vicinity of the hearing aid  1 . 
     If the right-hand hearing aid  1  transmits, the second antenna  31  in the lanyard  3  receives a much stronger signal than the fourth antenna  21  built into the programming device which is further away. The field power coupled into the second antenna  31 —reduced by the efficiency of the configuration—is coupled out at the third antenna  32  by the series circuit in order to then be received after a short distance by the fourth antenna  21  of the programming device  2  as an indirect signal  38 . The second antenna  31  is advantageously arranged so that, for a turning of the head  41 , the hearing aid  1  which is turned away from the programming device moves towards the second antenna  31 . Although this makes the direct received signal  12  smaller, it simultaneously increases the indirect signal component and compensates for the loss. 
     To increase the efficiency of the data transmission  37 ,  38  the antennas  31 ,  32  of the lanyard  3  are operated in series resonance. To do this capacitors  33 ,  34  are connected locally in series to the antenna inductances  31 ,  32 . The capacitance values are selected so that a resonance is produced for a selected working frequency. 
     In order to avoid losing wireless approval for the programming device  2  in the event of a subsequent replacement of the prior art lanyard by the lanyard  3  in accordance with the claimed invention, the configuration must be prevented from increasing the transmit field strength of the programming device  2 . Thus two diodes  35  oriented in opposite directions to each other are connected in parallel to the third antenna  32  which limit the voltage at the third antenna  32  to the low diode voltage. The field power coupled into the third antenna  32  can thus not induce any appreciable voltage. The current in the series resonant circuit remains so small that no significant additional field strength is added in the remotely arranged second antenna  31  compared to the direct field. 
       FIG. 3  shows an inventive configuration similar to that depicted in  FIG. 2  with the difference that two second inductive antennas  31  are now arranged in the lanyard  3 .  FIG. 3  shows the head of a hearing aid wearer with a left-hand and a right-hand hearing aid  1 . To program the hearing aids  1 , the hearing aid wearer wears around his neck the programming device  2  attached to the lanyard  3 . To guard against strangulation the lanyard  3  includes a safety release element  36  which opens when the lanyard  3  is subjected to a predetermined force. 
     Arranged in both hearing aids  1  are first inductive antennas  11  for wireless data exchange  12  with the programming device  2 . The programming device  2  has the fourth inductive antenna  21  as the communication partner. During data exchange  12  data is exchanged inductively between the hearing aids  1  and the programming device  2  on a direct path. 
     To improve the signal power an indirect signal transmission path  37 ,  38  is additionally used. Two second inductive antennas and a third inductive antenna  32  are incorporated into the lanyard  3  for this purpose. The antennas  31 ,  32  are preferably wire coils wound onto a ferrite core. The two second antennas and the third antenna  31 ,  32  are connected by an electric series circuit with the aid of an electrical connecting line  39 . The third inductive antenna  31  is arranged in the vicinity of the fourth inductive antenna  21  of the programming device  2  and the two inductive antennas  31  are arranged in the neck area of the hearing aid wearer in the vicinity of the hearing aids  1 . 
     If the hearing aid  1  is transmitting the second antenna  31  in the lanyard  3  located in the vicinity receives a much stronger signal than the fourth antenna  21  built into the programming device  2  which is further away. The field power coupled into the second antenna  31 —reduced by the efficiency of the configuration—is coupled out at the third antenna  32  by the series circuit, in order to then be received after a short distance by the fourth antenna  21  of the programming device  2  as an indirect signal  38 . The second antennas  31  are advantageously arranged so that, for a turning of the head  41 , the hearing aid  1  which is turned away from the programming device  2  moves towards the second antenna  31 . Although this makes the direct receive signal  12  smaller, the indirect signal component  37 ,  38  simultaneously increases and compensates for the loss. 
     To increase the efficiency of data transmission  37 ,  38  the antennas  31 ,  32  of the lanyard  3  are operated in series resonance. To do this capacitors  33 ,  34  are connected locally in series to the antenna inductances  31 ,  32 . The capacitor values are selected so that a resonance is produced for a selected operating frequency. 
     In order to avoid losing wireless approval for the programming device  2  in the event of a subsequent replacement of the prior art lanyard by a lanyard  3  in accordance with the claimed invention, the configuration must be prevented from increasing the transmit field strength of the programming device  2 . Thus two diodes  35  oriented in opposite directions to each other are connected in parallel to the third antenna  32 , which limit the voltage at the third antenna  32  to the low diode voltage. The field power coupled into the third antenna  32  can thus not induce any appreciable voltage. The current in the series resonant circuit remains so small that no significant additional field strength is added in the remotely-arranged second antennas  31  compared to the direct field. 
     The advantageous placing of the hearing aids  1  close to the second antennas  31  means that a turning  41  of the head  4  during programming of the hearing aids  1  is far less critical for the hearing aid wearer than with a conventional lanyard. 
       FIG. 4  shows curves  52 ,  53  of a comparative measurement of the received field strength at the programming device  2  in accordance with the configuration of  FIGS. 1 and 2 . The right-hand hearing aid  1  is active as the transmitter. If the hearing aid wearer turns their head  4  to the right (negative angle), the signal level when using a lanyard  3  in accordance with prior art becomes critically low even at −60° (curve  53 ). This means that it falls below a nominal value curve  51  specifying the minimum required receive level. When the inventive lanyard  3  is used, the level (curve  52 ) only falls below the required value curve when the head is turned by around −85°. 
       FIG. 5  shows a further inventive embodiment with the second antenna  31  being embodied as a wire loop antenna occupying a large part of the lanyard  3 . The safety release element  36  contains plugs and sockets which, if safety is compromised, open up the lanyard  3  and disconnect the wire loop antenna  31 . Apart from this, the explanations given for  FIG. 2  apply. The longitudinal extent of the wire loop antenna  31  means that a rotational movement  41  of the head  4  does not have a disadvantageous effect on the inductive data transmission  37  between hearing aid  1  and wire loop antenna  31 .