96 B3000 need help!

My 96 Mazda B3000 is making a very odd noise. While I'm in motion, it makes a sound like an airplane is passing overhead. Its loudest is when I am going my fastest. When I come to a stop, the noise stops. Does anyone have any idea what's wrong with my truck?

You have to give more details where the noise is coming from and what type of noise. Grinding? Whining? Squeaking? Squealing? Front? Rear? Transmission? Manual or auto? Belt squealing?
You may get more responses. Good luck.