Sorry for the delay.
If this is noisy then its usually either the drum wheels or the jockey wheels the belt runs round.
To check you need to remove the top and then the back panel.
Then you need to remove the metal drum support on the back.
From there you need to reach in on the left and remove the belt from the wheels and then you can remove the drum.
With these out you will see the drum wheels and the jockey wheels and see if any are worn. Try turning them by hand and check them. If any are worn then they need to be replaced.
If they are fine then check the motor and see if this is causing the noise as if the bearing is worn it can cause a noise.
Check them out and see what you find and let me know.
To be honest its quite rare for the motor bearing to go but it can happen.
Are all the fans on tight? If theres any play in there then that could cause the noise.
But usually on a dryer when they make a noise its either the motor, fan or jockey wheels at fault here.
what you say it sounds like a worn fan. What you need to do is replace the fan and see how it goes from there.
Fingers crossed that will cure it. Let me know how it goes.