Flash :: Create A Parametric Equalizer In Flash?

I'm trying to create a parametric equalizer in Flash. I've been looking for a way to read audio data and mess around with the samples before Flash plays them on the fly. Loading a sound in one Sound object and using Sound.extract() to read the data, processing it, then play a second second empty Sound object and writing the data to its sampleData event seems to be the way to do it (please correct me if I am wrong or there is a better way).

Is there a way to use Sound.extract() while the Sound object is still loading a sound file? I don't want to have to wait for the entire sound file to load before it plays. Unfortunately, whenever I use Sound.extract() while the Sound object is still loading, it returns a zero-length byte array.

Is there a way to wait for enough samples to load first before playing? I imagine I'd have the same problem again when the Flash movie eats through all the loaded samples while the sound file is still loading.

Here's a simplified version of my code. It's working so far, but only when I wait for the Sound object to fire an Event.COMPLETE event.

var inputSound:Sound = new Sound();
inputSound.load("somefile.mp3");
inputSound.addEventListener(Event.COMPLETE, loadComplete);

[Code].....

EDIT: If I try using the PROGRESS event, I'm going to need to do a lot more low level stuff to implement buffering and whatnot (anything else I need to account for?). Could someone help me out with that? Also, is there a way to tell the position of a sample in milliseconds? Do I have to assume that all sound files are 44.1 kHz stereo (they may not be), or is there a better way?