Foley is the reproduction of everyday sound effects that are added to films, videos, and other media in post-production to enhance audio quality.

Common examples include footsteps, chewing, drinking, cloth movement, keys jingling, doorknobs twisting, etc. Foley is often much more time efficient than manually editing sounds in, and it provides a richer character and performance (and thus, realism) to certain sounds in the film.

-wikipedia

-soundsnap