The BBC Research & Development team have created a wonderful experiment recreating the sounds of the BBC Radiophonic Workshop. You can generate radio sound effects from the 1960s with four Web Audio API powered creations. Each demo comes complete with a little bit of history behind the original equipment and annotated source code.
There are Gunfire Effects, the Wobbulator, Tape Loops, and the Ring Modulator for you to play with. You could spend hours creating sounds and exploring the source! (You’ll need a browser that supports the Web Audio API for all that, of course.)