Deeper noise = larger amount, roughly. Larger bubble has some sort (logarithmic?) correlation to size. It's necessarily rough though.
Oh, interesting. Somewhere higher in the comments, people think the pitch is chosen at random and only the volume is controlled by the data.
Does this mean that a huge transaction for the right amount will hit the perfect low note, and cause everyone within earshot of listentobitcoin.com to simultaneously crap themselves?