An introduction to some particles in After effects: http://ae.tutsplus.com/tutorials/motion-graphics/create-a-sound-reacting-3d-waveform-animation-without-3rd-party-plugins/
This was the tutorial I used to find out how to extract key frames from audio with a visual spectrum in order to produce the candle experiments.
Here are some screen shots of what I produced after deviating a little from the tutorial:
