have to think of the realisation part. Just using the Arduino with no additional software may be difficult. ‘Processing” has a few quite simple examples referring to sound when you download the programme.
However with its very straightforward interface we still decided to use MaxMSP.
Our light source will be different colored LED (We already tested the experiment with small ordinary LEDs). So far, we used the microphone of our computer, but that one will be exchanged to a small one.
Since the arrangement as shown in the sketch above does not really look nice, I was trying to find ways how to position things better. So, the idea of a cone like a loudspeaker came into my mind. You could hide the Arduino, all the ugly wires and the LEDs in there. Then it would not only be a light show, but a light speaker. By speaking into it, it does not raise the volume of your voice, but it creates light effects.