| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the recording of sounds and voices other than the voice of an instructor into a microphone used to collect the voice of the instructor in remote lesson. <P>SOLUTION: A close-talking microphone always collects the pronunciation of the instructor and supplies the voice signals to a delay circuit. The delay circuit delays the voice signals by a predetermined time period, and supplies the signals to a control circuit. During the time period when the vibration detected with a bone conduction microphone has a magnitude greater than a threshold value, a transmission control section turns on a switching element. During the time period when the switching element is on, the voice signals to be supplied from the delay circuit are taken into the transmission circuit via the switching element, and transmitted to a sound emitting apparatus. <P>COPYRIGHT: (C)2008,JPO&INPIT |
