Intermittent Whir, Wheel Bearing?

[davey205 7 1 Cars]

Offside front appears to be every few seconds a what can only be described as whir type sound, kind of like when you go over a bit of funny road and u get that tight little vibration, it does it randomly i've had the wheels off to look and can see no impediment of the brakes in any way. Also tried bouncing the front and it behaves as expected - no untoward noises.

Forgive my naivety I'm really not very mechanically minded!