Lamphone Software, written in C for a device, that is able to retrieve a sound from a light source (like hanging bulb or light diode). For details, sound samples, results, and hardware required, look at the presentation: https://docs.google.com/presentation/d/1kopdMpLZ5V1QUh9cHoY5Cwp5ARLthqXu3Wm77XxfdGo/edit?usp=sharing