PURPOSE: To secure a single structure for an expansion microphone and to avoid the lowering of the reliability which is due to a defective contact, by modulating the aural input of the microphone and then supplying the aural input to a sound recorder of a sound camera through a wave guide support.

CONSTITUTION: A microphone rod antenna type supporter 203 which is expandable is provided to a sound cinecamera 201. The voice supplied to a microphone element 204 in a wind noise preventing wind breaker 205 of a microphone is converted into the electric signals. These electric signals are converted into the modulated signals by a modulator 211 after modulating the carrier wave sent from a carrier wave generator 210. The modulated signal is received at a carrier wave tuning circuit 212 through an antenna 203 to be turned into the aural signal after the amplification and wave detection. The aural signals are superposed through a bias transmitter and a mixer 210 and then recorded by a sound recording head 220. The inconvenience caused by a defective connection between the antennas can be further improved if the modulation frequency is increased.