Audio sound reproduction based on nonlinear interaction of acoustic waves

Audio sound reproduction based on nonlinear interaction of acoustic waves i n a duct is investigated. Special emphasis is given to the sum and differen ce frequencies generated by the nonlinear effects. It is found that the dif ference frequency component changes with the changes of two primary waves. When the frequencies of the two primary waves are shifted to ultrasonics, t he only audible sound is the difference wave. This finding opens the possib ility to reproduce the audio sound by nonlinear interaction of two ultrason ic waves.