Foley describes the practice of creating audio effects for a film by using physical props. That means to achieve the sound of a bone breaking you might break celery in half (yes the food) and with some clever post processing create the illusion of a breaking bone.
Foley mostly sound ‘more realistic’ than the real thing to our ears, and not just because the props on a film set often do not react the same way acoustically as their real life counterparts. Whenever you hear a fire burning, its more likely than not, a bunch of tape that’s being smushed by a foley artist. Yes, there’s an actual job for this – according to the Motion Picture Editors Guild, you can expect to earn roughly $2,000 per week or $42 per hour do this fun and creative sound design.