oh forgot to mention. could be the idelor pulley. they are known to chirp a bit too. PS beer fixes belt squeak. i figured it out on day on my old escort.. was leaning over under the hood with the engine running and split my brew on the belt system.
like the other guy said check your idler pulley,i change a good amount of those when iwas working.also check your belt tensioner make your is not to stiff.when they go like that they are not able to keep proper tension on the belt. they are spring loaded.good luck