Why is sound so important in a film?

What is sound? Vibrations that travel through the air or another medium and can be heard when they reach a persons ear.
What is a soundscape? A piece of music considered in terms of its sound components.
What is sound design? The process of specifying acquiring manipulating or generating audio elements.
What is 'suspending disbelief'? Willingness to suspend one's critical faculties and believe the unbelievable.
Sound is so important in a film because it adds to the effect that the film is trying to get across to the audience, for example in a horror movie normally when something is going to jump out and scare us it goes completely quite so we can get the full effect or a jingle is played. This adds to the scariness to the film. However, in a action film, when drums and base music is played this is normally when a fighting scene is going to kick off this is also done to add to the ruff violence effect the film wants. Furthermore, sound makes a tittle sequence much more fun to watch.
Lastly, sound is a way the film can communicate with the audience as they know when certain things are coming and also in some way what genre it is because when you here up beat, happy music you instantly would know this isn't a horror and is most likely a comedy or animation.