JPH0446520B

PURPOSE:To design a strong binding by composing a face plate with such hardened synthetic resin as acrylic resin, by composing a shell with such a soft synthetic resin as vinyl chloride to fit to the external ear and the external auditory miatus, and combining stickily the face plate wit the shell as a double combination. CONSTITUTION:A shell 11 at a degree of 1-2m/m thick is formed by a mold from an impression pattern of the external ear and the external auditory miatus. The shell 11 is composed of such a soft synthetic resin as vinyl chloride, and the powder of acrylic resin and acrylic ester monomer, preferably paste like one mixed with methyl meta acrylic methyl ester are heaped up on the edge 11A in accordance with thickness of the shell 11. The edge is formed flatly to be hardened by polymerization. Thus, a sufficient and strong binding can be designed because the face plate consisting of the hardened synthetic resin as combined stickily with the shell consisting of soft synthetic resin through a polymer composed of acrylic resin and acrylic ester.