Since the killer is featured with a gas mask as part of his appearance, we considered using sound effects that can be implemented into the trailer during editing. Members of our group suggested that we included a ragged breathing sound to play whenever the killer's scenes appeared or perhaps when the killer strikes. We also came up with the idea of using the Wilhelm scream to play when Wilson is dragged away over the floor. Charles conducted some research to discover that it was a "cinematic sound cliche, and by 2011 had been used in many instances, including over 225 movies." He also mentioned that it would be easily identifiable within the horror genre, thus targeting the right audience.
Source - http://en.wikipedia.org/wiki/Wilhelm_scream
