Durlach et al. (2000) outlined a research program for the use of virtual environments (VEs) to train spatial abilities, and have invited comments. Our perspective is that some of the problems facing researchers in VE navigation, and also perceptual-motor skills, stem from the possibility that psychological processes that underlie navigation and motor skills in real and in virtual environments may be somewhat different. VE users may then have to make use of different strategies and abilities to those that they would normally use to manually manipulate and to navigate around the world. We suggest that such differences may arise because, when performing VE motor skills and navigation, the subject is effectively disembodied.

Gilkey and Weisenberger (1995) discussed the experience of sound and its importance for a sense of presence within an encompassing virtual environment. In this paper, we develop Gilkey and Weisenberger's work in three ways. Firstly, we review theoretical work regarding the role of auditory information in perceptual experience. Secondly, we report on previous empirical studies of induced hearing loss that have implicitly addressed issues pertinent to an understanding of presence in virtual environments. We draw on this work to further inform the theoretical contribution made to the study of presence with regards to auditory experience. Thirdly, we report our empirical work on induced hearing loss, addressing issues associated with presence using both qualitative and quantitative methodologies. We report our findings and discuss methodological issues surrounding the investigation of presence. This work found that participants have difficulty in expressing their experience within the constraints of more-traditional research methods. Evidence emerged of different forms of presence experience, including, in our terminology, social, environmentally anchored , and self-presence. Finally, we discuss the implications of this work for the development of immersive virtual environments.