It's hard to hear anything in your wav file, but if you're talking about the high pitched sound, then I agree with EODguy... it sounds as if you might have a stuck caliper piston.

Jack up that corner of the car and see if the wheel is hard to turn due to a brake pad dragging.

AM.

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E70 2010 3.0 M57 AT Titanium Silver with Black Leather
E53 2004 3.0 M54 AT Toledo Blue with Gray Leather
E83 2008 3.0 N52 AT Silver Gray Metallic with Black Vinyl
E46 1999 2.8 M52TU 5MT Black with Tan Leather 250K+ miles (Sold, but not forgotten)