Go to some mechanic or call him home, take off your engine belt. See if you still get the sound or not. Drive for 200-300meters only otherwise your car will heat up as water pump won't be working.
If you don't get any sound with above experiment, then go to some good mechanic and ask him to diagnose that which pulley is making sound or not.
Worked for me, and my car is sound free now Alhamdullilah.