Abstract: A contact arrangement in a housing including a cover, the housing and cover defining a battery chamber having an opening closable by the cover, the chamber having dimensions substantially corresponding to the dimensions of a button battery to be received in the chamber through the opening thereof, and the battery having a negative pole and a positive pole, which comprises two contact elements arranged within the battery chamber to contact the battery poles. One of the contact elements is a pre-tensioned V-shaped spring having two legs arranged to be pressed apart against the tensioning bias of the spring by the battery upon insertion of the battery into the chamber through the opening thereof, and one of the spring legs is arranged opposite the opening and biases the inserted battery into a predetermined position in the chamber. The other contact element is arranged in the range of a free end of the other spring leg and insulated therefrom.

Abstract: A hearing aid adapted to be worn in the ear, comprises a housing receiving a sound transducer and a sound amplifier, the housing being shaped to fit into the ear and having an upper rim, a mounting plate defining a space for holding a battery and a sound volume adjustment control, the mounting plate having a circumferentially extending outer rim, and detachable fastening means connecting the upper housing rim and the outer mounting plate rim.

Abstract: To provide a mass-producible hearing aid adapted to be inserted into the external passage of the vast majority of human ears while leaving the concha unencumbered and without requiring individual impressions, the invention proposes a hearing aid which comprises a housing, a coupling element connected to the housing in communication with the sound emission opening of the hearing aid, and a sealing plug detachably connected to the coupling element and having an end remote from the housing, the sealing plug being comprised of cylindrical inner part mounted on the coupling element and an outer part turned back from the inner part at the remote end.