What is the difference between noise and sound?

I suppose it depends who you ask. Luigi Russolo seems to think sound is made from natural entities and noise comes from man-made machines. Sound is any vibration that a living species can hear, whereas noise is usually a loud and disturbing sound. I think Russolo's comparison of the two does not really make sense considering noise is a sound also, and nature creates many odd noises, but I understand what he was trying to say. It doesn't quite matter how you define these terms as long as you utilize what the ear hears in a compelling manner.

Noise as art is completely reasonable. An artist is supposed to use their creativity and apply it to a medium. By changing the volume of one noise and increasing delay on another, someone is making an executive decision to alter a medium and create a new piece. Sound goes the same way. If sound is comprised of vibrations, by altering the vibrations to an aesthetically pleasing new sound (or unpleasing depending on the artist's goal), one is starting a new work of art. It doesn't matter what you call sounds and what you call noise, but if you combine and change them in the right way the result can offer a different emotional response to the viewer than a traditional medium. Sometimes if it is combined with a visual aspect as well, the message could be stronger, but I think there is something to be said for closing your eyes and imagining a picture or place based on sound alone.