Sound vs No Sound

It's clear to anyone who has seen their fair share of horror movies that sound is what creates the tension. Music creates an ambient tone that gets people ready for something exciting to happen. In this scene with no sound, it looks like a very inconspicuous girl deciding to take a shower. When the person with the knife appears, since the audience wasn't anxious in anticipation, there was almost no psychological reaction. With sound, however, the scene is far more effective. The music sets a tone for the audience to expect something to happen. When the person with the knife enters the bathroom, it's psychological effect is far more prominent. My primary point is that in a good portion of movies, music has a far greater effect than we give it credit for.