Abstract: A system, more particularly a hearing aid, consisting of a microphone and a preamplifier, wherein the microphone comprises a housing having therein an opening to the surroundings, a diaphragm and a backplate, while the amplifier is coupled to the system consisting of the diaphragm and the backplate and has a field effect transistor as input element. In the housing, in a space which is bounded by, on the one hand, the diaphragm and, on the other, the housing wall, and which does not comprise the opening to the surroundings, a pressure equalization opening is present, which has a diameter such that in the audible audiospectrum it does not make an essential contribution to the suppression of low frequencies. In the input stage of the amplifier, at the output of the field effect transistor, a low-pass filter or a high-pass filter or a combination thereof is arranged. Through this measure, the frequency characteristic can be optimally influenced to suppress noise.

Abstract: The present invention relates to an electro-acoustic transducer suitable for applications within mobile communication equipment and hearing aids. The transducer comprises two diaphragms positioned on opposite sides of a magnetic circuit having two magnetic gaps. When used as a microphone the transducer is substantially insensitive to vibrations, and when used as a speaker the transducer generates only very low vibration levels. The magnetic circuit has a number of advantages compared to conventional transducers with circular magnetic. The transducer can be made lightweight and with very compact dimensions compared to conventional designs. In a preferred embodiment the diaphragms are rectangular. The transducer may additionally be used as a vibration generator for silent alarm signals.

Abstract: The present invention relates to a receiver module being adapted to be positioned in an ear canal, the receiver module comprising a receiver having a receiver housing, said receiver being adapted to receive a time dependent electrical signal, said receiver further being adapted to generate outgoing acoustic waves via an output port in the receiver housing in response to the received time dependent electrical signal, and expansible means surrounding at least part of the receiver housing, said expansible means having an opening aligned with the output port of the receiver housing so as to allow the generated outgoing acoustic waves to penetrate away from the receiver module and into the ear canal.

Abstract: An acoustic receiver comprises means for converting an input audio signal into an acoustic signal. The receiver has a housing having a plurality of sides that surround the converting means. One of the sides include an output port for broadcasting the acoustic signal. A jacket fits around the housing and has sections for engaging the sides. The sections are generally flat. The jacket may also form a gap with a corresponding side surface of the housing. A printed circuit board can be located within the gap. The printed circuit board including electronics for processing said input audio signal.

Abstract: A microphone assembly for mounting in an electronic communication device, and wherein the microphone assembly comprises one or more sound inlet port(s) with channels (7), and one or more microphone(s) inside a housing (1). One or more controlling means (5) are an integrated part of the microphone assembly, said controlling means comprising a sound inlet part (6) composing a button and being surrounded by a second casing part (8), the button being loaded by a spring (9). The housing (1) comprises a terminal (2) for grounding the microphone, a terminal (3) connected to e.g. a battery, and a terminal (4) for signalling out.

Abstract: The invention relates to an integrated microphone/amplifier unit, in particular for a hearing aid, which is largely insensitive to interference signals such as, for instance, could be caused by GSM telephone apparatuses because capacitive couplings are arranged between the amplifier output and ground, and between the feed and ground. These capacitive couplings are made by the thick-film technique and can be provided with a separate ground connection. In one embodiment the capacitive couplings comprise capacitors, of which the output and feed connections themselves form part. In another embodiment the capacitive couplings comprise capacitors that are formed on the back of a carrier.

Abstract: A transducer which is particularly suitable for hearing aids is set forth which has improved resistance to mechanical shock. The transducer includes a coil having a tunnel, a magnetic member with a pair of magnets defining an air gap and an armature extending through the tunnel and into the air gap. The coil is rotated with respect to the magnetic member in a manner such that the coil forms a stop for the armature, thus preventing excessive deflection of the armature leg in the occurrence of a shock. The armature may also be provided with expanded edge portions which assist in limiting its deflection.

Abstract: A transducer, in particular suitable for hearing aids, comprising a coil, two spaced magnet elements, a membrane, and a U-shaped armature, a first leg of the U-shaped armature extending through the coil and the two magnet elements and being coupled with the membrane by means of a connecting element, limiting means being provided for limiting the maximum deflection of the first leg of the armature, which limiting means are disposed on the connecting element.