Microphone for a hearing aid

The invention relates to a microphone for a hearing; the microphone has a housing with an input device, enter the sound waves into the housing leaves, a transducer means, the electrical sound waves to a Converts signal, an amplifier device, which this electric signal amplified, and a connecting device on, the amplifier means the with the terminals a battery connected and the output of the amplifier means to a receiver sets. Such microphone disclosed example. EP-A-0802700.

Furthermore, the invention relates to a hearing aid with a Main section, a microphone of the above type, a battery and a receiver receives.

Although hearing aids nowadays much smaller than a few years ago, while reliability and sound were improved, still remain drawbacks to overcome the are. These are eg. The number of wires required are to the microphone, the amplifier, the receiver and to connect the battery. These wires may reliability affect the hearing aid and expensive its production. Furthermore, they are at least partially Identify disorders through mobile phones and other RF sources. So there are expensive solutions needed to such disturbance to prevent. Another disadvantage is the format of the known Hearing aids are still too large, to a (mini) canal instrument (CIC hearing aid) for all ears fit.

With the known hearing aids is the microphone generally an electret microphone with integrated CMOS or JFET buffer stage. The amplifier has one or more discrete components and integrated circuits on a hybrid circuit board on. Recipient is generally a design with balanced armature ( "balanced armature ").

EP-A-0802700 describes a Microphone, the housing of which a differential preamp contains.

The DE-A-19545760 proposes into a microphone for a hearing aid a integrating A / D converter, while according to US-A-4,592,087 and US-A-4,669,819, the power amplifier in integrates the microphone of a hearing aid shall be.

The invention will still existing disadvantages the known hearing aid at least partially overcome and this provides for a hearing aid of the above Type a microphone prepared which is characterized in that in microphone housing An electronic circuit is provided, which has an output, at which a signal available is that is transferred directly to the recipient leaves.

Preferably, all active components the electronic circuit into a single integrated circuit combined.

If necessary, can be some passive components - for example. resistors or capacitors - outside the microphone housing provide.

In a further embodiment a microphone according to the invention are outside the housing fixed, spring loaded terminals for solderless connection with the battery terminals provided.

According to yet another embodiment of the Invention, the main part of the hearing aid with a battery holder detachable cap and is an entry device for sound waves provided from the exterior of Main part of the interior of the battery holder and the battery holder to the interior of the microphone housing runs. Preferably, the inlet means for the battery holder in the removable Cap formed.

Embodiments of the invention and its advantages are discussed below with reference to the figures of the drawing.

<figref idrefs="S9">1</figref> is a section through a first embodiment of the invention;

<figref idrefs="S10">2</figref> is a section through a second embodiment of the invention; and

<figref idrefs="S11">3</figref> is a section through a third embodiment of the invention.

The <figref idrefs="S9">1</figref> shows a portion of a main part <figref>1</figref> a hearing device with a battery holder <figref>2</figref> With removable cap <figref>2a</figref> For a battery <figref>3</figref>, A receiving space for the housing of a microphone <figref>4</figref> and a inlet duct <figref>5</figref>In which sound waves from the exterior ago to the inlet port <figref>6</figref> in a wall of the microphone housing be able to walk.

The microphone is a conventional Elektroet microphone of the type, as for example, in US-A-5,255,246 is described; Details of the microphone are not executed here because it for the present invention are not really relevant. A hybrid circuit<figref>7</figref> is provided on which an integrated circuit (IC) <figref>8</figref> and if necessary passive components <figref>9</figref>. <figref>10</figref> by means of a flip-chip technology, or wire bonding are arranged. The connection of the microphone to the substrate of the hybrid circuit is done by a flexible connection disclosed in US-A-5 255 246 type disclosed. At the present on the housing exterior side the hybrid substrate, are soldering surfaces <figref>12</figref>. <figref>12a</figref> to the Connect the microphone to the battery terminals via lines <figref>13</figref>. <figref>14</figref> and to extract the output of an amplifier in the receiver IC provided. For clarity, only the solder surfaces<figref>12</figref>. <figref>12a</figref> shown, However, not provided for connecting the receiver and the Recipient selbstö their structure is for those skilled in the art.

Instead of soldering surfaces can also be other Connecting devices - eg. a film strip with printed lines ( "Flex Print") - use, instead of a hybrid circuit and a printed circuit or Flexprint.

by In the structure of a microphone <figref idrefs="S9">1</figref>&lt;?page 3?&gt;all sensitive electronic parts from the outside world by the metal housing of the shielded microphone and by the side of the hybrid circuit, on the ground plane is. External components such as. the components <figref>9</figref>. <figref>10</figref>Which, for example, to decouple the Power supply are needed do not need to be shielded because it either on a relatively high Signal level and therefore work against RF interference signals far less or are not sensitive.

In the embodiment of <figref idrefs="S9">1</figref> the microphone can be round, rectangular or other desired have shape.

The <figref idrefs="S10">2</figref> shows another embodiment of the invention, in which the number of connecting wires further is reduced. The same components as those of the<figref idrefs="S9">1</figref> are the same in each case, but to 100 increased Reference numerals. The hybrid circuit is now in the body of so arranged that it lies facing a side of the battery. Spring preloaded fasteners <figref>114</figref>. <figref>115</figref> are provided, to the a battery terminal - in Generally the Minuspol- with the microphone housing and the other battery terminal - in general the Plus pole to be connected to the hybrid circuit. The connecting wires<figref>116</figref>. <figref>117</figref> for transferring the amplifier output signal to the receiver remain the same, but now come from the other side of the case as in <figref idrefs="S9">1</figref>, These wires are by means of the soldering surfaces <figref>112</figref>. <figref>112a</figref> With the hybrid circuit <figref>107</figref> connected. In this embodiment, the microphone is preferably round. In consequence of the spring-biased Fasteners this hearing under construction very simple and inexpensive, while the short connections to the battery, the risk of RF interference radiation reduced.

In the embodiment of <figref idrefs="S11">3</figref> are the connections to the battery and the receiver the same as in <figref idrefs="S9">1</figref>; for her are the same, but increased by 200 reference numerals as in <figref idrefs="S9">1</figref> used. In this embodiment, is provided in the body of sound inlet opening for the microphone to an advantageous Arrangement changed. In this embodiment can the sound into the microphone through openings <figref>215</figref> in the Wall of the battery holder <figref>202</figref> - Preferably in its cover <figref>202a</figref> - and through an opening <figref>216</figref> in of the microphone housing facing wall of the battery holder to enter. In this way are sound waves, and in the battery housing via the battery holder the sound inlet of the microphone occur well against sweat, dust so protected, in conventional embodiments often the reliability affect. With this structure also increases the bandwidth of the microphone, as the acoustic mass of the conventional Plastic tube as sound inlet - see Fig. <figref idrefs="S9">1</figref> and <figref idrefs="S10">2</figref> - the Frequency response of the microphone adversely affected.

The microphone according to the above-described third embodiment requires in a hearing aid less Volume than the conventional Microphones. Therefore, one achieves a greater flexibility in the design the hearing aid because u. a. the sound inlet no additional Space on the front panel of the hearing aid requires, which is already occupied by switches, potentiometers, etc.. furthermore call the various manufacturers of hearing aids today microphones with different Sound inlet channels. With the microphone of the third embodiment also, this is now a problem of the past.