this is an experiment to try and generate acoustic feedback using a candle flame. a small candle is placed on top of a loudspeaker which is connected to the output of an amplifier. a solar panel is connected to the amplifier's input and placed next to the candle.

the flickering of the flame is picked up by the solar panel and converted into an electrical signal, which causes the speaker to vibrate. this vibration resonates the candle, causing its flame to flicker more and the whole process feeds back on itself creating sound.