Manufacture of hearing aid for deaf person involves production of curved housing with molded half-shells containing actuator knob, microphone, loudspeaker and sound conducting tube

摘要

An electrical lead (9) is connected to the loudspeaker amplifier unit (14) and passes into a cable sheath inside a plastics cover (10). The cable includes four guide wires (8). Typically there are one central wire and three equispaced side wires. The cable may have a miniature loudspeaker at the distal end, and the proximal end fits in a cable guide (12) with a large diameter entrance bore (20a) and a small diameter exit bore (20b). The sheath has a male thread (13) on its inner end engaging in a female thread (17) in the housing.