Front end noise

I have a 2001 Windstar SE Sport. When driving down the road we hear what appears to sound like road noise. It is worse about 60 miles an hour. There is no noise when braking or turning. The tires have been checked and rotated. When tires were rotated the noise seemed to get worse. It is on the passenger side front. Both front rotors get extremely hot with very little braking. The van does not pull when braking and there is no noticable vibration in the steering wheel. The back drums stay cool. The noise is kind of between a hum and a thump. What should I be looking out to get rid of this noise?
Starboy

I have a 2001 Windstar SE Sport. When driving down the road we hear what appears to sound like road noise. It is worse about 60 miles an hour. There is no noise when braking or turning. The tires have been checked and rotated. When tires were rotated the noise seemed to get worse. It is on the passenger side front. Both front rotors get extremely hot with very little braking. The van does not pull when braking and there is no noticable vibration in the steering wheel. The back drums stay cool. The noise is kind of between a hum and a thump. What should I be looking out to get rid of this noise?
Starboy If you are talking of a hum, I would suspect a front bearing. You could try that; lift the van on the side that you hear the noise, ( the suspect wheel has to be free of the ground) leaving the other side on the ground. Block the rear wheel for safety, start the engine and put it in drive. Smootly accelerate but you don't have to reach 60 miles but the half, because only 1 wheel si turning. Notice what you hear, you should probably hear the hum. Don't forget to apply the brake before putting the gear in park. Now do the same thing for the other side ( the one that seem OK) and check for the hum that you have heard on the other side; if this is quiet ( if I can say) you could really look at the wheel bearing on the noisy side.