If a tree falls in the forest, and nobody is around to hear it, does it still make a noise?

no. sound is produces by the shape of your ear canals so when a human's ear is not there to make this occurance happen, no one hears it.

well, that's only half-right. it depends on your definition of "sound". if you use this definition: "Vibrations transmitted through an elastic solid or a liquid or gas, with frequencies in the ...