these fans cost a few cents/pennies and all usually end up noisy,

a fix? it will certainly help is to oil the bearing.

there is usually a sticky label in the centre of the fan, lift this and you should be able to see the bearing, a tiny drop of thin oil can then be added, wipe off any excess and replace the label, sometimes the glue on the label is not good enough to stick, if this is the case a small square of insulating tape will do.

this method works on most computer fans and can quite even the noisiest machine