external amplifier was able to detect the sound waves from microphone on speaker and oscilloscope. The maximum amplitude of output speech signal of amplifier is 45 mV, and the maximum output of MEMS microphone is 1.125 µV.

A historical overview of some of the early theoretical and experimental work on dust acoustic waves is given. The basic physics of the dust acoustic wave and some of the theoretical refinements that have been made, including the effects of collisions, plasma absorption, dust charge fluctuations, particle drifts and strong coupling effects are discussed. Some recent experimental findings and out...

We formally derive the simplest possible periodic wave structure consistent with time-periodic sound wave propagation in the 3 × 3 nonlinear compressible Euler equations. The construction is based on identifying the simplest periodic pattern with the property that compression is counter-balanced by rarefaction along every characteristic. Our derivation leads to an explicit description of shock-...

A topologically stable quasiparticle normally associated with spin textures in magnetic materials has now been created using sound waves air.