This could be many things
I think this is more likely a bent wheel or a rear differential problem, rather than a CV joint. CV joints are more noticeable on turns. 75,000 miles is a little early for hub bearings to be wearing out, though not out of the question. If you purchased this vehicle new, the hubs and CV joints should be covered by the power train warranty, as long as proper maintenance has been performed. Check your owner's manual to be certain.
To see if you have a bent wheel, if it is on the front, you can feel it through the steering wheel when you are moving slower than five miles an hour. If it is on the rear, you can have someone watch you drive away at a very slow speed. If he/she doesn't see a wobble, you don't have a bent wheel. Alloy wheels can be bent.
If the noise is due to a bad differential, it should come predominately from the rear and should be more of a whine. Hubs usually begin to squeal, at first, then later growl.
You should, also, check your universal joints.
