The next sound in the soundtrack is sound effects, sound effects caneither be synchronous or asynchronous. For sound effects to be synchronous, thesound must be synchronised or matched with the action it is representing onscreen.
If a man was playing a piano in the film and the sound of the keysbeing played were in time with the man playing, then the sound effect would besynchronous. Synchronous sounds enhance the realism of the film and also aid increating the desired atmosphere and tone of the film. As an example, the noiseof a door is used as a familiar noise that the audience will recognise thesound of so can just be used as an element to show the realistic noise of adoor. But if you were too add some ominous background music and build up acreepy atmosphere before the door opening sound, then the door opening soundsmore suspenseful and engages the audience into being curious about who or whatis opening the door.
To enhance this further the editor may increase the soundeffect to add to the tension. The opposite is asynchronous sound effects. These are the sound effectsthat do not match the action that is on screen, these could be sounds thatcreate a subtle difference in tone or again to add to the authenticity of theworld created in the film.
This technique is often used in disaster films suchas “Shaun of the Dead’ to fill parts of a scene where no one is talking to fill thesilence. There is a scene in the film where the two main protagonists aresneaking round their back garden, instead of them walking around in silence youcan hear car alarms going off in the background to connote the chaos going onaround them. As well as the connotations the alarms bring, it also what wewould imagine the end of the world would sound like so as the audience we are throwninto the world seeing it as realistic despite the zombies. Finally, the last and one of the most important pieces of the soundtrack,the background music. By adding in background music you can again control thetone of the scene but you can also control the pacing of the film itself orcharacter movement; Edgar Wright does this in most of his films. Particularly inhis most recent, ‘Baby Driver.
‘ In this instance, Wright wrote the music soundtrack along at thesame time with the rest of the script which is the exact opposite of what mostother writers do. The opening for this film is shot in time with the song ‘Bell Bottoms’, which is a song that hasa distinctive tone change halfway through the song. So Wright decided to usethe first two minutes of the song as a timer for the heist crew to rob the bankand when they return to the car, the music kicks in and a car chase begins witheach tyre screech and police siren set to the beat.
Sometimes, film makersdecide to fade music in slowly to foreshadow something that is about to happen,for instance in HBO’s Game of Thrones TVseries, a song called ‘Reigns of Castamere’ plays before something tragic happens to the Stark family caused bythe Lannister family.