PARAMETRIC SPEAKER

PROBLEM TO BE SOLVED: To provide a parametric speaker constituted only of general purpose components, capable of producing an audible sound by transmitting ultrasonic waves with high efficiency at a low cost, and including a frequency modulator, a frequency divider, a preamplifier, a power amplifier, an inductive element, and an ultrasonic wave transmitter.SOLUTION: When an audio signal is input to a signal input, and a drive voltage for transmitting ultrasonic waves from an ultrasonic wave transmitter is generated, the parametric speaker performs frequency modulation based on an audio signal at a frequency equal to or higher than two times of a frequency transmitted from the ultrasonic wave transmitter, divides the frequency of a pulse voltage subjected to frequency modulation, and drives the ultrasonic wave transmitter in a state where the duty ratio of the pulse voltage is always close to 50%, thus transmitting ultrasonic waves from the ultrasonic wave transmitter efficiently when compared with conventional means.