Ever since the introduction of sound in film, sound effects have played a big part in the experience of the film audience. Acousmatic sound effects are diegetic sounds that lack a visual source on screen, and they are frequently used in horror films. This research explores the relationship between familiarity with sound effects and the emotional response in the audience. An experiment was conducted where two test groups watched an excerpt from a horror film where acousmatic sounds were a big part of the soundtrack. One of the test groups watched a version where there were reoccurring familiar acousmatic sounds, and the other group watched a version with random un-familiar acousmatic sounds. Data was collected through self-report and physiological measurements. The results suggest that there is a dissonance between the conscious and unconscious emotional experience of suspense and fear. The physiological measurements indicate a higher emotional arousal in the group that watched the unfamiliar version of the stimuli, while the self-report propose a stronger conscious build-up of suspense leading to a stronger experience of fear in the group watching the familiar version. Further research directions based on the result of this research are presented.