Abstract: A method for forming a part inserted in the auditory canal of a hearing impaired person, said part being either an otoplastic or a carrier part of the hearing aid insertable into the auditory canal or an ear adaptor member for a hearing aid to be worn behind-the-ear, characterized by providing an expandable elastic member, coating said elastic member with a hardenable material, inserting the coated member into an ear of the person who is hearing impaired, allowing the hardenable material to harden to retain the outside contour of the part. The elastic expandable member may be either a porous member which is partially saturated on the outer surfaces or may be a smooth member which is coated with the hardenable material. If desired, a physiologically compatible coating may be applied onto the hardened surface layer subsequent to the hardening process.

Abstract: A hearing aid has a housing insertable into the auditory canal, wherein the housing contains at least a microphone, an amplifier, an earpiece and a power source. In instruments of this kind it has turned out to be desirable to have, in addition to the usual volume control, an additional control for varying the way the incoming sound signals are influenced by the amplifier (i.e. its characteristic) to adapt to individual hearing impairments. For this purpose the hearing aid provides in the housing space for the battery a pitch control in such a manner that its actuating member can be operated at least when the power source is removed from the instrument. This makes it possible to reduce the space requirement for the pitch control so that even hearing aids insertable into the auditory canal can contain such an additional control.

Abstract: A miniature hearing aid (1) includes a microphone (12), a receiver (14) an amplifier (15), and a battery connectable via a contact (18), all of which are contained in a housing (2,3). The amplifier is constructed of a printed circuit board (20) and a plurality of components (21). In order to save space, the components (21) are countersunk in openings (24) in the circuit board (20) to reduce the vertical dimension of the amplifier. The openings (24) are used as temporary supports and for exact positioning for the components (21) by making them rectangular with cut off edges.