Probably not the belt itself... Well, maybe you could check timing belt tension? Your description didn't really sound like a loose belt slapping around.

You had the external belts off... How were your alternator bearings? Is it possible that's what the noise was?

Inside the timing cover, about mid-height, is the tensioner pulley & the water pump. Either one can be making noise if its bearings are going bad. How many miles on that stuff? If you get in there at all, you'd be silly NOT to replace the timing belt.