Research into similar products (sound in horror films)

sound in horror films makes the scene either look happy, eerie or extremely scary. the effective use of sound can also help promote the emotions of the characters to the audience. the diegetic sound of the door squeaking as it opens at 0:12 makes the scene as it adds to the effect of the scary location as they are in a creaky old abandoned house which is the typical scene in horror films.
the voices that are used (predominantly by the possessed female) throughout the trailer reflect the fear of the characters the best example would be at 0:11 to 0:55, the tone of the voice shows that she is clearly scared and frightened. compare this to the tone of the same female character at 1:34 where when she talks it is a very deep and strong which is well suited to the part as the character needs to create fear. in the trailer they have to use sound to create fear because the possessed female wouldn't create the same level of fear if her voice was high pitched.