| 摘要 |
A hearing aid with a microphone, with at least one amplifier fed with the signals from said microphone, whereby the amplifier cooperates with a filter of a higher order for influencing the frequency response, and with a loudspeaker which transforms the amplified signals into soundwaves. This filter (3) can be arranged in the conventional manner between two amplification stages or in the feedback loop of the amplifier (6). In order to allow the optimal adjustment of the frequency response to the respective requirements it is provided in this hearing aid that the filter (3) is arranged as a multiple filter with a biquadratic structure and comprises at least two integrators and an inverting amplifier, whereby the active elements of their components are formed by transistors, preferably single transistors (T1, T2, T3). The feedback loop of the amplifier (6) is guided through an adjustable potentiometer (RA) for setting the filter emphasis or de-emphasis and in the filter circuit (3) there is arranged an adjustable potentiometer (RF) for setting the mid-frequency of the filter (3).
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