The parameter given to the output(...) method can be any valid Javascript expression that returns some numeric value.

This application is mostly untested due to my laziness. Most likely trouble occurs when trying to generate very long audio files. The best performance was with Opera.

Why?

I hacked this together one evening after I read this article at work. A few days later I discovered that someone had already built such an application:

  <The original bemmu version>
  <And another one>

But anyway, what's done is done and I had fun.