Noise

I have a 1993 Pontaice Grand Am. I'm getting a loud noise from the front end that increases with speed. I have checked all wheel bearings, drive axles look ok and the boots are not torn.The car has 147,000 miles on it. I've had it since new and have maintained it myself.Also I took all four tires from my 1996 Grand Am to see if it was a tire problem, but the noise still continues.Also changed transmission fluid and screen which wasn't brown or anything. The noise starts at about 25 mph and gets louder as I increase. I'm at a loss at this point. Any help would be great.Thanks.