Spatial perception and immersion - Audiovisual perception and virtual reality

The dossier on spatial perception, immersion and virtual reality includes three articles dealing successively with :

• image-induced perception of space or visual perception of space [TE 5 182] ;

• sound-induced perception of space or auditory perception of space [TE 5 183]  ;

• perception of space, immersion and virtual reality, the subject of this article, which deals with the simultaneous perception of visual and auditory data relating to space. Contrary to what one might think, this dual perception rarely gives rise to a juxtaposition of information.

The different ways of integrating images associated with sounds can range from fusion (convergence) to occlusion (a single perceived signal), passing through several intermediate stages, including dissociation (two distinct signals) and summation (virtual objects, delayed fusion, pseudo-convergence...).

Fusion processes play an essential role in the perception of space. They involve respecting the temporal and spatial coherence of signals, as well as the convergence of movements and displacements. They depend on the quality and respective dimensions of the image and sound.

The immersion resulting from the convergence of visual and auditory information is a sensation that integrates two components: a sensory component (psychophysical) and a mental component (psychological).

Cinematic immersion is a very good model of these perceptual modalities. It depends largely on the nature of the sound elements. Each component of the "soundtrack" - voice, sound effects and music - induces its own modes of integration.

The examples given in this article highlight several forms of immersion. In addition to its sensory or mental, frontal or spatial components, we are led to extend its definition to the integration of "frequency space" and the perception of time.

The combined action of the three forms of immersion - spatial, spectral and temporal - provides a clearer picture of the impact of the expected developments in virtual...