I have a 05 ram 1500 and it makes a loud noise while going 30 to40 mph. It will stop if I take my foot off the gas or hit the gas hard. The truck is lifted so I know there is going to be some noise but it's has seemed to get loader

 

Uhhhh.....going to need a little more description than that. What type of noise? A whine? A banging sound? Scraping metal? Where is it coming from on the truck? Shot in the dark it could be a broken exhaust manifold bolt, that would create a whining sounds that vaguely resembles your description. You need to be more specific though.