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루이스 교수의 학업 웹사이트

Sound in Film

Types of Film Sound

There are three types of film sound: dialogue, sound effects, and music.


The dialogue is the verbal narrative of the script, recited by the actors. A good actor will not merely repeat the words, but will bring meaning and life to it through the way he or she performs. To do this the actor uses pauses, intonation, emotion, voice volume, pitch, accent and dialect, and so on.

Under the dialogue heading we may also include the voice-over, where "someone" is speaking to the audience. The voice-over can be used to inform the audience of background information, inner-dialogue, and so one, which is often important for the coherence or comprehension of the narrative.

Sound Effects

Sound effects are an important component of a film’s sound because it contributes lots of important details to the film, and to the audience’s understanding of the scenes. Sound effects can help the audience identify the location of the film – the sound of crickets could indicate a rural night scene, while the sound of traffic bustling by may suggest a city environment. The sound also suggests certain moods to an environment. Horror movies, for instance, may employ “scary” noises to create a feeling of suspense and fear. Sound effects can also indicate the environment’s impact on characters. A famous example is the “Crop Duster”-scene from Alfred Hitchcock’s North by Northwest (1959) where the audience can hear the plane coming closer and going further away, even though it is not always visible on the screen.

Sound effects have certain characteristics that you need to know about: acoustic qualities; volume; regularity; verisimilitude (sounding authentic).


Music has an important function in film and contributes important meaning to the narrative. The music may establish the historical context for the film. The music also contributes to shaping the space and helps the audience establishes the space of the scene. It also helps to shape the emotional tenor of the scene. A sinister melody may create a suspenseful mood, or a merry melody may create a corresponding cheerful mood. Music can also contribute to defining character – well chosen music can become associated with certain characters, and so add to the characterization of that character. The music could also “distance” the audience when the sound and the image contradict. Such well thought out juxtaposition of music and image by the filmmaker may give special meaning to the scene.

Music has five characteristics. Patterns of development (compare with motifs); lyrics; tempo & volume; instrumentation; cultural significane.

The Relationship between Sound and Image

The typical expectations are that the sound we hear should correspond with the image we see, and that the soundtrack should enhance the mood of the scene. When two actors speak to each other we expect to hear the dialogue, unless they are whispering; when a gun is fired we expect to hear the bang, unless it is fitted with a silencer, in which case we expect to hear a muffled shot. Also, when two lovers kiss we expect romantic music; conversely, in an action film sequence we expect fast paced music, or in a thriller there might be suspenseful sound effects.

However, the sound may differ from what we see and what we expect to hear. There are five ways in which the filmmaker can choose to create contrast; i.e. not conform to the audience's expectations. The five situations are contrasts in:

  • onscreen space and offscreen space

Offscreen sound is known as “acousmatic sound” – you cannot see the source of the sound. For instance, if you can hear the sound of police car sirens coming closer, but never actually see the police cars, this is an example of offscreen or “acousmatic” sound. If you can see the origin of the sound, it is known as “visualized sound”.

  • objective images and subjective sound

Sometimes the audience can hear certain sounds which the characters in the scene cannot hear. For instance if you are privy to the thoughts, the inner-dialogue of one character that other characters cannot hear, then that sound is subjective.

  • diegetic (story) details and non-diegetic (not part of the story) sound

Sounds that does not form part of the actual story is known as non-diegetic sounds. The film may include special sound effects as an example. When a character listens to a radio, the audio from the radio is diegetic. However, if there is background music (e.g. acousmatic music) that the characters cannot hear, and is therefore not part of the actual diegetic (story), then that sound is non-diegetic.

  • image time and sound time

At times the sound you hear does not match with the things you see, it is either faster or slower – sound may continue from one scene into another scene connecting different scenes together (a “sound bridge”) or there may be a voice-over informing the audience of things that happened in the past or will happen in the future. These are all examples of when the timing of the image and the timing of the sound do not match.

  • image mood and sound mood

The soundtrack is often chosen to match the mood of different scenes in the film. However, a filmmaker may decide to use sound that seems inappropriate to the mood of the scene, in so doing creating supplementary meaning. The effect could be disturbing, humorous, ironic, etc.