Abstract: With a hearing aid device, filter parameters of filters are to be adjusted for feedback suppression. It is hereby proposed that test signals are emitted via an earpiece in order to estimate the transmission behavior of the feedback path, and response signals to these test signals are recorded by a microphone and analyzed in the hearing aid device. In this way, information signals which are already occasionally emitted by the hearing aid device and can be perceived by the user are used as test signals. Information signals of this type are particularly well suited as test signals and are perceived by the user as non-interfering.

Abstract: The aim is to be able to determine the spatial structure of an ear canal in a simple and reliable fashion. To this end, it is proposed to produce a hologram of the ear canal, by inserting a holography unit at least partially into the ear canal. The data for the shape of a housing shell or an otoplastic can then be obtained from the resulting hologram for automatic manufacturing methods.

Abstract: In order to improve the electromagnetic compatibility strength in a hearing aid and for particularly protecting the active components of the amplification and transmission circuit of the hearing aid, the integrated for the amplification and transmission circuit is provided with a shielding that forms a line trap against radio-frequency signals.