It becomes noisy when the engine revs or when the wheels are rolling?
One qucik check you could do for the wheel bearings is this -
Back - it may be practical to disassemble the spindle, clean the bearings and races and inspect.
Front - normally these bearings are sealed and will probably not be re-useable once removed. with the front wheels off the ground [don't forget to use jackstands and not just some crappy jack itself, and the parking brake set. safety...] but try to wiggle the wheel side to side and see if it moves excessively. It should be tight and move only with minimally. With the car in neutral, spin the front wheels and if you can hear any akward noises...
If you find it is the front wheel bearings, remember that they are not easy to replace and once the old ones are out, they are finished.
Another possibility is there is something in the transmission making these noises. That should be left to a shop for repair.
1999 LeSabre, 3800 series II engine.