Patent Publication Number: US-7711132-B2

Title: Hearing aid

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to the German application No. 10 2004 001 500.7, filed Jan. 9, 2004 which is incorporated by reference herein in its entirety. 
     FIELD OF INVENTION 
     The present invention relates to a hearing aid having a reception device for receiving an input signal, a registering device for registering a hearing aid value, a signal generating device for generating a device signal as a function of said hearing aid value, and an output device for feeding out an output signal based on the input signal and device signal. The present invention further relates to a corresponding method for operating a hearing aid. 
     BACKGROUND OF INVENTION 
     Signal outputs for program changes, volume adjustments, end of battery life etc. are customary in present-day hearing systems or, as the case may be, hearing aids according to the publication EP 0 557 847 A1. The signal that is fed out is what is termed a device signal, which is to say a signal generated by the hearing aid itself. A device signal is typically generated in the form of a whistling tone. It is generally possible to set at least the frequency and level of said device signal. 
     SUMMARY OF INVENTION 
     It is nevertheless the case that loud ambient noise will prevent the perception of device signals that are very important for the hearing aid wearer. As an instance of this, device signals are obscured by street noise. This problem can be combated by raising the level of the device signal. This will at least reduce the frequency of occurrence with which the device signals are obscured by loud ambient noise. A disadvantage of raising the level is that, especially in a very quiet environment, the device signals will then be experienced as being highly irritating and disagreeable. 
     A combined hearing aid and audiotone-playing system is known from the publication DE 100 40 660 A1. Externally generated audiotone signals and artificially generated information or warning signals can here be received by a receiving unit belonging to the hearing aid. The received signals can be merged in within the hearing aid, compressed, and mixed in a mutually adjustable manner in terms of frequency response and volume. 
     An object of the present invention is thus to optimize the perceptibility of device signals in hearing aids. 
     Said object is achieved by the claims. 
     A method is furthermore provided for operating a hearing aid. 
     The principal advantage of the present invention is that prevailing ambient noise is taken into consideration during automatic or, as the case may be, adaptive matching of the device signal. The same advantage comes into effect in the converse case of matching the hearing aid input signal to the device signal. Obscuring can also be successfully prevented advantageously by mutually matching the two signals. As a result, the device signals will, on the one hand, always be perceptible and, on the other hand, will never be experienced as being disagreeable or too loud. Automatic matching of this type will furthermore help enhance the operating convenience and satisfaction of the hearing aid wearer. 
     The hearing aid value preferably represents a setting value, a status value, and change-of-setting information or change-of-status information. A device signal will be generated thereby in the hearing aid if for example, a certain hearing program has newly launched or the charge level of the hearing aid&#39;s battery has become low. 
     The specific type of device signal can be generated as a function of the hearing aid value. As an instance of this, the frequency of occurrence, the volume, or the melody of a battery status signal can be changed automatically with the charge status of the battery. The duration and level of the device signal and/or its type can furthermore also be matched to the input signal. In this way it is possible for example for the input signal to be muted for a comparatively long period of time before the device signal is fed out when an input signal is loud, while when an input signal is quiet it can be muted a shorter period of time before the device signal is fed out. This will allow obscuring effects to be for the most part prevented. 
     The level of the input signal can alternatively or additionally also be matched to the device signal. Obscuring effects can likewise also be prevented or reduced in this way. A specific form of this would be total suppression of the input signal when the device signal is fed out. It is possible in this way to ensure that the device signal will be perceived. 
     In a highly preferred variant the device signal is temporally matched to the input signal. The device signal could in particular only be fed out when the input signal is below a predefined level. This will prove particularly advantageous in the case of status information which is not very time-critical such as, for example, that relating to the battery status. 
     It can in general be ensured that matching of the device signal to the input signal or of the input signal to the device signal will take place as a function of the level and type of the input signal and/or a classification thereof. A simple decision criterion can thus be provided for said matching. 
     Specific advantages will also ensue from a combination of the above-cited variants, which is to say from reciprocal automatic mutual matching of the input signals and device signals. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be explained in more detail below with reference to the attached drawings, in which: 
         FIG. 1  is a block diagram of a hearing aid with muting of the input signal; 
         FIG. 2  is a block diagram relating to raising the level of the device signal; 
         FIG. 3  is a block diagram relating to setting the level of the device signal and the level of the input signal; 
         FIG. 4  is a block diagram relating to downward adjustment of the input level when the device signal level is constant; and 
         FIG. 5  is a block diagram of a case in which input signal processing takes place ahead of device signal generation. 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
     The exemplary embodiments described in more detail below are preferred embodiments of the present invention. 
     The block diagram in  FIG. 1  shows a hearing aid according to a first embodiment with which an input signal can be muted so that a device signal can be perceived by the hearing aid wearer. The input signal of a microphone  1  is to this end routed to a changeover switch  2  before being routed to a further hearing aid signal processing device  3 . A device signal is generated with the aid of a generator  4 . Said generator is driven by means of a control logic  5  for generating a signal. The control logic  5  simultaneously drives the changeover switch  2  so that the device signal from the generator  4  can be sent instead of the input signal to the further hearing aid signal processing device  3 . 
     The control signal in the control logic  5  can be triggered manually via a control element  6 . An operating interface  7  connected between them generates a corresponding drive signal for the control logic  5 . Said control element can be, for example, a program-changing switch, a remote control, or a volume adjustment wheel. A drive signal is consequently also sent to the hearing aid signal processing device  3  from the operating interface  7 . Said drive signal can be used, inter alia, to “freeze” compression, background noise suppression, and other adaptive algorithms associated with signal processing while device signals are being fed out and to resume signal processing applying the same setting values when the device signals have been fed out. 
     Toward that end, the control logic  5  has a timer for specifying the duration of the deactivation of the input signal as well as the duration of the device signal. A control signal is sent by the control logic  5  to the generator  4  and to the changeover switch  2 . When a device signal is triggered, muting of the input signal can thus be achieved that is of longer duration than that of the device signal so that masking effects can for the most part be precluded. Muting takes place prior to and during output of the device signal. 
     According to a second embodiment of the present invention, shown in  FIG. 2 , the level of the device signal is set automatically such that it exceeds that of the current input signal at least by a certain extent. The changeover switch  2  shown in  FIG. 1  is to this end replaced by an adder  9 . So that the level of the device signal can be varied by the generator  4 , a gain adjuster  10  is connected between said generator and the adder  9 . The level of the device signal can thus be regulated via the control logic  5  using the level of the input signal. A control line (dashed arrow in  FIG. 2 ) is additionally provided from the control logic  5  to the adder  9  in order to activate or deactivate the addition of the two signals. It is thereby possible, for example, to deactivate the device signal generator while the hearing aid is in normal operation or not to acoustically indicate a program change by means of a device signal if the hearing aid wearer so wishes. On the other hand, the input signal could also be muted with the controlled adder as in the case of the first embodiment. 
     The third embodiment, whose block diagram is sketched in  FIG. 3 , is an even more convenient solution for reliably perceiving a device signal. This solution is based on the second embodiment and is supplemented by a second gain adjuster or, as the case may be, regulator  11  connected between the microphone  1  and the adder  9 . It receives the level of the input signal from the level meter  8  as the manipulated variable. It is also driven by the control logic  5  in order, for example, to downwardly adjust the gain in good time before the device signal is fed out. It is thus possible when feeding out the device signal with a required level to adjust the level of the input signal to below that of the device signal and keep it constant. 
     A fourth embodiment of the present invention is shown in  FIG. 4 . This embodiment is essentially similar to the first embodiment, except that in this case the input signal is not muted but, instead, is adjusted in terms of its level to below that of the device signal. The input signal will then continue to be audible. In component terms, this embodiment is a simplified third embodiment because it dispenses with the gain adjuster  10  between the generator  4  and the adder  9  and because the gain adjuster/regulator  11  is implemented as a simple gain adjuster  12  receiving no feedback signal from the level meter  8 . With the gain adjuster  12 , the level of the input signal can in this way be adjusted up or down via the control logic  5 . 
     According to a fifth embodiment of the present invention, a device signal will only be fed out if the input signal falls below a certain level for a predefined period of time. This embodiment is not shown in the figures. It has a pause-search algorithm by means of which a time segment having a low level of ambient noise can be determined. A waiting device signal can then be transmitted in this time segment. This means that transmission of the input signal for conveying the device signal will not be irritatingly interrupted or attenuated. This type of notification for the hearing aid wearer would suffice for less time-critical status information such as that relating to, say, the battery status. 
     According to a sixth embodiment of the present invention shown in  FIG. 5 , the hearing aid signal processing device  3  is connected upstream of the device signal injector. The input signal is accordingly fed directly into the hearing aid signal processing device  3  whose output signal is then forwarded to the device signal injector. According to the variant shown in  FIG. 5 , where the device signal injector corresponds to that of embodiment 4 ( FIG. 4 ), the output signal of the hearing aid signal processing device  3  is accordingly routed to the gain adjuster  12  and to the level meter  8 . Further processing takes place analogously. It is, however, also possible to use, for example, the device signal injectors according to embodiments 1 to 3 instead of the device signal injector shown in  FIG. 5 . 
     The components shown in  FIGS. 2 to 5  not cited in the associated description are explained in more detail in connection with  FIG. 1 . Reference is therefore made to the relevant part of the description relating to  FIG. 1  for details of how these components are connected and how they operate. 
     Any practical combinations of the six embodiments presented above are of course also conceivable. Different embodiments can, for example, be implemented simultaneously in the hearing aid and also activated as a function of the input level.