Foleying is a means of supplying the subtle sounds that production
mikes often miss. The rustling of clothing and the squeak of a saddle when a rider
mounts his horse give a scene a touch of realism that is difficult to provide
during the original recording. The kissing you hear during a steamy sex scene was probably created by a
Foley
artist making dispassionate love to his or her own wrist.
Foley is not about sound effects but about the atmospheric sounds that go
almost unnoticed.
The good Foley artist must "become" the actor with whom they are synching
their sound-effects otherwise they will lack the necessary realism and not be convincing.
Our sense of hearing is very subtle.
The foley crew will include the artist or 'walker' who makes the sound and
a technician to record and mix the result.
A foley stage looks like an areas of junk with walking surfaces for
the production of all types of footsteps. The artist develops an instinct that
will enable them to produce the sounds with a few simple pieces of equipment
plus lots of experience and experimenting.
Sounds are not a substitute for words in an audio story but subtle sounds can
be employed effectively to help create the mood or sustain the story if silence
is essential to the plot.
http://www.filmsound.org/foley/