Are you serious? I'd really like to hear it. The lousy original Bando serpentine belt is usually the cause of such suspected noises, and it inevitably ends up squealing and squeaking. Replacing with a GoodYear Gatorback belt is the usual fix.
Your 2009's serpentine belt tension must be properly set with the adjustable tensioner beside alternator. It may be noisy if too tight, which could lead to pump/alternator/tensioner pulley bearing failure... Start by checking if your belt seems too tight, and replace belt with a Goodyear Gatorback if you're still on original belt.
My original 2004 alternator is also fine at 170k miles. Corolla alternators are still as reliable in more recent models.