if it was wheekl bearings then i think the noise would go by road speed not enginge rpm .could be tyres could ,be g box best get it checked .bearings cost about 30 quid from factors but are a press fit. you can do it yourself but need a fare amount of faith and a big vice
WOOSH . sorry mate that is the sound of an auto box box flying over my head.
im sure someone will help though
AGAIN GOOD LUCK although auto boxes are a bit of a speciality
ps have you checked the road wheel / stub axil for play " 12/6 oclock and 3/9oclock>
Nah, tried that does not work. The bearings are in pressed in sealed units sor they have to be replaced. ~Did you see the how to in the Clio Articles, I got a swivel hub from a breakers and swapped it over, it's always a risk on how good the bearing is but the car is in constant use plus cost £15 with drive shaft and shock absorber. That way I have gained a spare hub which I could get a new bearing pressed into in my own time.
Have you had the levels checked in the gearbox - the fact you say the noise is worse when free-wheeling downhill could be the diff is low on lubrication. If level is low it could lead to expensive gearbox repairs. I have heard wheel bearings whine when there is little or no play or movement in them. Check the gearbox levels first as this would be comparatively cheap to do and may save in the long run.