20 Things You Didn't Know About The Exorcist
2. The Head-Twisting Sound Is That Of An Old Leather Wallet
The Exorcist used a number of innovative and unsettling tricks to help make it one of the most frightening films to ever feature in cinemas, and a truly bizarre invention was used in one of the films most famous scenes.
It should be no surprise that a doll was used to create the unearthly effect of Regan turning her head 360 degrees behind her body. The sound Regan's head makes was created with something much more mundane.
Sound wizard Gonzalo Gavira commandeered a crew member's old leather wallet, twisting it repeatedly up against a microphone to produce the sound of the head twisting unnaturally. The tortured sound that was produced seems like the perfect accompaniment to the unsettling motion seen on screen, and it was achieved using the simplest of objects.