SOUND DETECTOR AND SOUND DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To simplify a sound detection system and to stably detect sound signals. SOLUTION: A frequency converter 10 is provided with a linear amplifier 11 that amplifies a sound multiplex carrier signal while keeping linearity, an oscillator 12 that outputs a signal to generate an intermediate frequency signal (IF signal), and a multiplier 13 that mixes an output signal from the oscillator 12 with a signal outputted from the linear amplifier 11 to generate the IF signal and has a dynamic range by which the IF signal keeps the linearity to the sound multiplex carrier signal received by the linear amplifier 11.