A thesis submitted in partial fulfillmentUniversity of Washingtonof the requirements for the degree of
Master of Science in Engineering
University of Washington
1994
Approved by
(Chairperson of Supervisory Committee)
Program Authorized
to Offer Degree
Date
In presenting this thesis in partial fulfillment of the requirements for a Master's degree at the University of Washington, I agree that the Library shall make its copies freely avail-able for inspection. I further agree that extensive copying of this thesis is allowable only for scholarly purposes, consistent with "fair use" as prescribed in the U.S. Copyright Law. Any other reproduction for any purposes or by any means shall not be allowed without my written permission.
Signature
Date
Exploratory Studies on the Sense of Presence as a Function of Visual and Auditory Display Parameters in Virtual Environments
y Claudia Mary Hendrix
Chairperson of the Supervisory Committee: Professor Woodrow Barfield
Department of Industrial Engineering
The focus of this research was to develop subjective measures of presence in order to relate the amount of presence experienced within a virtual environment to visual and auditory display parameters. Furthermore, the research examined the relationship between presence and performance in spatial judgments. To accomplish this goal three experiments were performed; the first two experiments investigated virtual presence as a function of auditory and visual display parameters used to design virtual environments while the third study investigated presence as a function of performance measures and visual display parameters.
The first experiment investigated the sense of presence within virtual environments as a function of visual display parameters while the second investigated the effect of auditory display parameters. The variables for the first experiment included the presence or absence of head tracking, the presence or absence of stereoscopic cues, and the geometric field of view (GFOV) used to design the visual display. The variables for the second experiment included the presence or absence of spatialized sound to a stereoscopic virtual environment display and the addition of spatialized versus non-spatialized sound to a stereoscopic virtual environment display. Subjects were required to navigate a virtual environment and to complete a questionnaire designed to ascertain the level of presence experienced by the participant within the virtual world. The results indicated that the reported level of presence was significantly higher when head tracking and stereoscopic cues were provided. Furthermore, the results showed that the GFOV used to design the visual display highly influenced the reported level of presence, with more presence associated with a 50 and 90 degree GFOV when compared to a narrower 10 degree GFOV. In the second study, the addition of spatialized sound did significantly increase ones sense of presence in the virtual environment. On the other hand, the addition of spatialized sound did not increase the apparent realism of that environment. This regardless of the fact that the addition of a spatialized sound source significantly increased the realism of the sound sources' apparent interaction with the subject and the use of spatialized sound significantly increased one's sense that sounds emanated from specific locations.
The third study investigated presence and performance in spatial judgments as a function of visual display variables. The variables for the third experiment included the presence or absence of headtracking, the presence or absence of stereoscopic cues, and the GFOV used to design the visual display. The results of the third experiment indicated that the addition of headtracking and stereopsis to the visual display did increase reported levels of presence, fidelity of the display, as well as subjective assessments of one's success in performing the spatial judgments. However, actual performance measures indicated that spatial judgments were not improved with the addition of headtracking and/or stereopsis. The 50 and 90 degree GFOVs did not effect performance or reported levels of presence. The implications of the effects of the visual and auditory display parameters on presence and performance in spatial judgments are discussed.
The research described in this thesis was supported by a contract from the Air Force Office of Scientific Research to Professor's Woodrow Barfield and Thomas A. Furness III (Contract # 92-NL-225 and INST PROP NO:78216).
I deeply thank my advisor and friend, Woodrow Barfield, for his patience and wisdom, and for teaching, guiding and supporting me throughout my graduate career.
I would also like to gratefully acknowledge the support of my committee members, Thomas A. Furness III and Blake Hannaford.
In addition, I would like to thank Paul Schwartz for developing the in-house software program "Precept", which was used to design the virtual worlds as well as Eric Danas and Robert Futamura for developing the audio interface design.
Last, but certainly not least, I would like to thank Linda Ng Boyle for her help in adhering to the many procedures and policies involved in presenting this document for acceptance.
This thesis is dedicated to my father, Donald W. Hendrix, who has taught me that anything is possible to achieve; the only limitations in our lives are those that we impose on ourselves.