Fourier Transform of Electric Signal using Kundt's Tube
  An experiment to demonstrate the Fourier transform of an electric signal using the Kundt's tube is described. The results of finding the component frequencies and an approximation to the amplitudes of two sinusoidal signals which compose an input electric signal is presented. Undergraduate students are expected to more easily relate to the meaning of a Fourier transform through such mechanical demonstrations. 
Srijit Paul and Mahesh Gandikota
physics.ed-ph