This example shows a wide variety of Web Audio API functions being used. You can see this code in action on the Voice-change-o-matic demo (also check out the full source code at Github) — this is an experimental voice changer toy demo; keep your speakers turned down low when you use it, at least to start!
The Web Audio API lines are highlighted; if you want to find more out about what the different methods, etc. do, have a search around the reference pages.