Read the full experiment at http://www.stevespanglerscience.com/experiment/talking-cups From the soulful crooning of an R&B singer to the deep roar of thunder, sounds are created by vibrations. So, if you're looking to make a cup speak, you have to find a way to make it vibrate. Combining the plastic cups with a toothpick and a length of string is the first step... but how do we make it talk?