I want to design an experiment to demonstrate Raman - Nath effect. Due to limited resources at my hand (my school doesn't have too much resources), my condition is somewhat like Raman, and hence I want to do the original experiment that Raman and Nath conducted in IISc Bangalore back in the late 1900s. The diagram of the experiment is this: As you can see, laser from the left will go through the liquid kept in the cylinder. There will be a sound source below the cylinder, which will create sound of same frequency but different amplitudes, so as to create fluctuations in the density of the liquid, which will affect the optical density, and thereby diffract the incoming beam, which will create a diffraction pattern on the screen. I have all the things mentioned above except the sound source. I had first decided to use a resonance box, so that I can make a resonance by vibrating a tuning fork of the same frequency, and holding it near the box. With this system, I could even vary the amplitude of the wave as I want by hitting the fork hard or soft. But i found that my school doesn't have the resonance box. I searched on the net to see if I could buy one, but the only one on Amazon is a bit expensive (about $80, which amounts to 5120 INR). Does anyone have an idea that could help me out of this situation? This is the only problem that I am facing.