Abstract: A hearing aid has a sound-conducting tube, the distal end of which extends into the auditory meatus. The tube is mounted to an earpiece which closes off the ear canal. A protrusion surrounds the distal end and extends from the earpiece. A cap is detachably secured to the protrusion and is perforated to permit sound to travel into the ear, and the cap and the earpiece form a cerumen-trapping gap. The earpiece of the hearing aid has a substantially flat end plate adjacent the protrusion and the end plate bears a groove which surrounds the protrusion.

Abstract: A rotary shaft is provided with at least two pins at its one end, these two pins fitting into two holes of the cover. The other end of the rotary shaft carries a polygonal screw pin for screwing on the adaptor.

Abstract: On the basis of a hollow die including over-shell and a cap drawn onto a proximal connector of the die, an ear impression is produced directly in the auditory canal that is filled with ear impression material. Displaced ear impression material thereby flows through a channel in the cap into the hollow interior of the die. A negative is produced from the ear impression together with a screwed-on fixing star, this negative containing impressions of the points of the fixing star. After injection of otoplastic material and repositioning of a fixing star with a die, over-shell and cap into the fixing depressions, a finished otoplastic shell can then be produced from the negative.

Abstract: A single opto-plastic 7 is provided which can be inserted into the auditory passage of an ear which is to be serviced and has an outside contour which matches the auditory passage and includes a hollow interior 6 which communicates with the outside through a sound passage 9. The hollow interior 6 is shaped so that it can receive an in the ear hearing aid 3 or a coupling (4, 5) for a behind the ear hearing aid, thus allowing either of the units to be quickly connected to the opto-plastic ear piece 7 so that comparative measurements can be made by the patient.

Abstract: A sound transducer, particularly an earphone, is buttoned into a sound opening of an in-the-ear hearing aid housing by means of an elastic hose part seated on a sound connector of the sound transducer. The elastic hose part is slightly pre-stressed in longitudinal direction and the sound transducer is provided with an elastic abutment that elastically compensates the prestress.

Abstract: A hearing aid has a housing which includes electronic components such as a microphone, amplifier, power source and receiver, as well as suitable structure for mounting and retaining those components. The housing is inserted in a cavity in a shell. The exterior of the shell is matched to the shape of the auditory canal of the user. The cavity of the shell in which the housing is received tapers to a smallest diameter at a sound discharge end of the shell. The housing also has a smallest diameter at this location. A releasable latch is disposed in the region of the smallest diameter for holding said housing in place within the shell during use, but permitting removal of the housing for repair or replacement without damaging the shell.