In films, this sound called acousmatic sound is used as the most effective medium to convey meanings that the visual medium tries to convey and more effectively. The audio-visual films are greatly enhanced by the use of acousmatic sound which creates an aura like effect with the additional information or meaning conveyed. There are layers of meaning that can be conveyed through the use of sound effects that do not reveal their originating source. In one of the papers by Bannerman in the Proceedings of Sound Moves: An International Conference on Music and Dance, he talks about "the shape of sound or simply its morphology that can be used to create different landscapes in the studio and hence work with sound at an elaborate morphological level" (2005). It is further observed that the acousmatic sound used in films is interpreted by the audience by relating it to known sources which is called 'source-bonding' by theorist Denis Smalley or infer some kind of abstract source that is left to the audience's imagination. This leaves space in the mind of the filmgoer to interpret a particular sound according to his imagination and have an individual experience of the film.
In films, there is a greater influence on the perception when acousmatic sound is employed. First, it helps the psycho-analysis process of understanding the message being conveyed by the visual effects, and also creates the desired effect for a longer time as the perception lingers for some time. It creates a lasting impression or perception of the sound sometimes, and is often associated with a particular event or vision. The audio-visual effect is enhanced by the creation of an acousmatic sound that most closely resembles the message or effect the film maker wants to convey than the visual impact of the scene. Film makers like Robert Bresson and Andrei Tarkovsky have used this theory of abstraction and ambiguity to their advantage and Bridgett rightly observes that "they have used this ambiguity theory in film making using acousmatic sound with an abstract origin and added more dimensions to the film. Hence, the aural image leads to a number of interpretations and add to the impact on the individual viewer's perception" (2004).
As ours is a visually dominant culture according to Forrester, the vision is effused with sound, particularly acousmatic sound to more effectively communicate the meaning of the situation in films. Further, Forrester cites Lipscomb and Kendall that any musical and visual relationship can be represented in two dimensional spaces and their observation that film composers have mastered the art of manipulating the perception of the audience by emphasizing particular events in the film without any attention shift to the main visual theme of the film (2007, pp42). It is observed that the visual impact does succeed to a certain extent in making an impact on the film goer but an additional impact with the use of music, prominently sound and particularly acousmatic sound has a greater impact on the perception of the scene in the film. It can associate itself with the sounds of the dynamics of the visual picture thus creating an aura around the visual. An example is that of a whistle of a train which is created by an acousmatic sound in the visual of a film to create an impression of the whistle though it is not the actual source of sound. This abstraction of the sound source leaves more space for the viewer to imagine the scene and create an impact much to his experience of the film.
According to Chion, "audio-visual scenes engage our mind in a pan-sensory experience speaking at different levels of