METHOD FOR GENERATING AND LISTENING TO VOICE AND SOUND SIGNALS USING METHODS FOR MODULATING AND DEMODULATING ULTRASONIC WAVE, AND SYSTEM CONFIGURATION THEREOF

摘要

PURPOSE: A method for generating and listening to voice and sound signals using methods for modulating and demodulating ultrasonic wave, and a system configuration thereof are provided to selectively transmit speech and sound only to people who want to listen to the speech and sound in a place where many and unspecified people exist. CONSTITUTION: A video signal storing unit(11) stores video and sound information. A divider(13) divides complex video signals into picture signals and speech signals. A monitor(14) displays the picture signals. An ultrasonic transmitter(15) generates the speech signals by using ultrasonic wave. A speech/ultrasonic wave modulator(16) modulates speech and sound signals into ultrasonic wave. An ultrasonic generator(17) emits ultrasonic wave signals to the atmosphere. An ultrasonic receiver receives the ultrasonic wave signals. A demodulator demodulates the ultrasonic wave signals to be restored to the speech and sound signals.