| 摘要 |
PURPOSE: An earphone device capable of reducing noise from outside to ears is provided to attach a mounting member to the both sides of the entrance of an external auditory canal not to be suppressed, thereby preventing the separation of the mounting member. CONSTITUTION: A sound tube has almost the same internal diameter as an external auditory canal. One end side of the sound tube is formed as an ear insertion mounting unit. A different end side of the sound tube is formed as the non-reflexive platform of voice. An external microphone unit converts a sound from outside into an electric signal outside the sound tube. The vibration plates of the units of an earphone unit and an internal microphone unit are mounted to face an intraluminal side on the peripheral surface of the sound tube. A variable mixing ratio means includes a level control means independently controlling each level of the electric signal and generates an output signal. |
