A method for generation of finite amplitude pulse of sinusoidal sound in free space

Abstract

Nonlinear response of acoustic materials to a large amplitude sound depends upon the incident waveform itself. For this reason, we intend to control the radiated waveform of finite amplitude in free space. In order to control the radiated waveform, the waveform control in a pipe was performed by the use of the loudspeaker driven by the computed waveform, and generated wave was radiated from an exponential horn connected to the end of the pipe. However, the observed waveform in free space was different slightly from expected one. As the result of the simulation for the sound transmission through the exponential horn, it became clear that the reflection of the mouth of the horn affected the radiated waveform in free space. Therefore, the waveform control in the pipe was performed by taking account of the effect of the horn and then the result obtained agreed approximately with the waveform expected.