摘要 |
The earplug inserted in the auditory canal is so designed that its inside end facing the tympanic membrane makes close contact with the surrounding hard bone structure, and its external end at the aperture of the auditory canal makes close contact with the surrounding tissue. The earplug has a head for connection with a communication system. A central channel conveys sound to the tympanic membrane. The mid-section of the earplug is furnished with a circumferential recess for receiving sound waves from the user's own voice through the surrounding soft tissue: and channels convey these sound waves to a microphone built into the earplug head. |