ABS noise

[Mejium]

So it snowed tonight, and I was driving home testing the brakes, and the ABS kicks in and other than the pumping sound it makes, their is a noise coming from the right front corner that sounds like a guitar string being plucked or like a tensioned spring being flicked, Boing, Boing. Anybody have any ideas? I own a 2001 subaru legacy L.

[SilentRacer]

sounds like a heat shield rattle on the exhaust

Is this the noise? at 13-15 sec in this video
http://www.youtube.com/watch?v=hbEeYw9v4Mk

[Mejium]

My heat shield does rattle like that at certain rpm, but the ABS noise is so much louder than that. It sounds like a plucked rubber band, but it resonates for 8 seconds after I hit the breaks, unlike my the heat shield which stops when I let off the gas.