Chirping sounds too bird like and restful - the sound mine makes is more like a knackered and overloaded old spin dryer on fast cycle. Its def the belt - simply pushing the belt up and down deflecting it a few mm gives a small sample of what its like at 60 Mph !
The teeth on the rear sprocket don't look healthy either - with wear lines on all faces.
Roll on the all steel replacements , as fitted to the front sprocket, which dont wear out.
