AS3 Sound Input NOT through Mic

hello Guys,

I already asked this before, but in the AS1/AS2 section, but there someone told me it was imposible to do this in AS2. So, I decided to make my game in AS3! ^^

I want to make like a line which goes up and down according to the input of sounds in the swf. But I can only find sound input ways through your mic and not like directly in the swf itself.
My question is: Is it possible to check the activityLevel of the sound file being played inside the swf withouth the use of a Mic, and if so, how?

Hope someone can help me!

Cheers,

~Sir Realism