Why is sound so important in film?

Sound is important in film as it does things such as revealing the Genre of the movie. For example if a sort of high pitch instrumental is used, it normally has to do with a Horror or Thriller. If a slow low tune is used that could be associated with a Romance. Sound also helps keep the audience interested and makes them feel more involved. Above I have included the trailer of a Thriller named Reasonable Doubt. Watch the clip first without sound, and then a second time but turn the sound on. You are most likely less interested when the sound is not playing as you don't feel 'on the edge of your seat' compared to when the sound was turned back on. This is just a few reasons as to why sound is so vital in production.