| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that two parties have to communicate in a loud voice over the telephone or by gesture when they ride in tandem on a two-wheeled vehicle, such as a motorcycle, or at a place where it is too noisy to talk over the telephone. <P>SOLUTION: An earphone as a combination of two or more stethoscope-like objects makes it possible to communicate by applying the principle of speaking tube. <P>COPYRIGHT: (C)2012,JPO&INPIT |
