I’m not sure if I’ve seen this before, if it’s on one of the already released DVDs or Blu-rays or if it will even be on the forthcoming The Exorcist (Extended Director’s Cut) Blu-ray hitting shelves on October 5. The features are multiple, but there’s no specific mention of this cool little video.
Just below is a look at scenes from The Exorcist featuring Linda Blair‘s original audio followed by the same scenes with the voice of the demon as provided by Mercedes McCambridge.
From a 2004 article at the New York Times:
Watch the video below, it’s almost just as creepy before the voice effects were applied as it is after.