Audio Signal Directional Communication Technologies

Directional propagation of audio signal is a new technology to control the propagation of sound. Ultrasonic wave which is amplitude modulated by an audio signal is radiated from a transducer into the air. Because of nonlinearity of the air, AM sound wave is self-demodulated and an audio signal is produced in the air. The sound beam id produced.Firstly, the property of propagation of sound wave and ultrasonic wave is introduced. The sound pressure and directional plot and nonlinearity effect while sound wave propagates are discussed. Secondly, the system of directional propagation of audio signal is designed, including its structure and function and property. At last, a lot of experiments are completed, and the experimental results are analyzed; the directivity and distortion are studied especially.The experimental results show this system achieves the purpose which controls the directional propagation of audio signal.