It's another real-time audio experiment, this one even less serious. Click the 'play' button and drag the dot across the screen to make "laser sounds".

Try it! (in a recent version of Chrome or Firefox).

An example - but there are other sounds to be made that I haven't discovered yet.

Moving left to right will increase frequency, moving downwards will increase harmonic content. Moving slowly to the left with a square wave can make 90s arcade-game like noises. Increase the 'sparkle' to create even older-sounding arcade game noises.

What's going on? I am playing one tone and quickly changing the frequency. When the frequency is changed slowly, one hears a typical siren like one would expect. If the frequency is changed more quickly, the result is a "tshu" pulse sound. Finally, if the frequency is changed very quickly, the entire quality of the sound can change. This is called FM synthesis, where FM stands for frequency modulation. Radio transmitters use Frequency Modulation, changing the pitch of a single note very quickly, to 'move' a signal in frequency to a very high frequency. Video games in the 90s also used FM synthesis; when putting this program in square wave mode and moving to the left, the sound resembles that of a DOS game or GameBoy handheld. Maybe I'll follow the work of some musicians (Bibio, Crystal Castles) in incorporating arcade-like noises into music.