For example, a film maker might opt to include the background sound of an ambulance's siren while the foreground sound and image portrays an arguing couple. Music Background music is used to add emotion and rhythm to a film. In addition, background music often foreshadows a change in mood. Background music may aid viewer understanding by linking scenes. For example, a particular musical theme associated with an individual character or situation may be repeated at various points in a film in order to remind the audience of salient motifs or ideas.
Film sound is comprised of conventions and innovations.
We have come to expect an acceleration of music during car chases and creaky doors in horror films. Yet, it is important to note as well that sound is often brilliantly conceived. The effects of sound are often largely subtle and often are noted by only our subconscious minds. Yet, it behooves us to foster an awareness of film sound as well as film space so as to truly appreciate a twentieth century art form, the modern film. Thomas Sobochack and Vivian Sobochack, An Introduction to Film, p.177.