US Patent 7602931 Gasket for reducing electromagnetic interference in a boundary microphone

A boundary microphone including a microphone case is provided whereby sufficient shielding performance can be achieved against strong electromagnetic waves of cellular phones. In the boundary microphone, a microphone case 1 includes a flat metallic base 10 opened on its top surface and a metallic microphone cover 20 mounted on the base 10 so as to cover the top surface of the base 10, the microphone cover 20 having a number of openings (sound wave introduction holes) thereon, the microphone case 1 housing a microphone unit 31, wherein a gasket 40 having elasticity and conductivity is disposed between the base 10 and an edge face 20a of the microphone cover 20.