Short Papers
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`May 7-11 1995 ■ CHI' 95 MOSAIC OF CREATIVITY
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`Audio Augmented Reality:
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`A Prototype Automated Tour Guide
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`Benjamin B. Bederson
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`Bell Communications Research
`445 South Street
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`Morristown, NJ 07960
`(bederson@bellcore.com)
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`beginning to experiment with it (see [2] for a collection of
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`KEYWORDS
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`Audio augmented reality, museum tour guides, virtual
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`several research articles, or [1] for a survey).
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`reality, social interaction.
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`MUSEUM TOURS
`One place a low-tech version of augmented reality has
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`ABSTRACT
`Augmented reality (or computer augmented environ­
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`long been in the marketplace is museums. It is quite com­
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`ments as it is sometimes called) uses computers to
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`mon for museums to rent audio-tape tour guides that
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`enhance the richness of the real world. It differs from vir­
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`viewers carry around with them as they tour the exhibits.
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`tual reality in that it doesn't attempt to replace the real
`While this technology works reasonably well, many peo­
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`world. Our prototype automated tour guide superimposes
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`ple using it become frustrated because it seems to obstruct
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`audio on the world based on where a user is located. We
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`some of their social purposes in attending the museum.
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`propose this technique for use as an automated tour guide
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`As with music, part of the reason many people go to
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`in museums and expect it will enhance the social aspects
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`museums is to socialize, to be with friends and to discuss
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`of museum visits, compared to taped tour guides.
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`the exhibit as they experience it. Taped tour guides con­
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`flict with these goals because the tapes are linear, pre­
`INTRODUCTION
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`planned, and go at their own pace. This makes it hard to
`For many types of information retrieval, social interaction
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`stay with friends because if one person turns off their tape
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`is critical to the experience. For instance, why do people
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`temporarily, it is very difficult to get synchronized again.
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`go to live music concerts instead of listening to compact
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`discs at home? Partly because of the different quality of
`In addition, the taped tours typically describe only a rela­
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`sound, but it is also largely due to the social experience of
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`tively small subset of the pieces on exhibit. The pieces
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`being at the live show, being with your friends, and being
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`described on tape may not be the ones a particular viewer
`part of the audience.
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`is interested in hearing. But because the tape must be
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`accessed linearly, it is impossible to skip over or access
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`Many people believe that computation enhances our
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`descriptions out of order.
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`everyday lives. But many of the forms in which comput­
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`ers aid us also work to isolate us. Perhaps the most glar­
`AUDIO AUGMENTED REALITY PROTOTYPE
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`ing example of this is virtual reality, where the main point
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`A more technologically sophisticated tour guide, on the
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`is to take us out of the physical world by replacing our
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`other hand, can offer the benefits of automation without
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`senses with computer-generated ones.
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`the social conflicts caused by the taped tour guide.
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`Augmented reality, on the other hand, is an attempt to
`We have built a prototype audio augmented reality-based
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`combine our real world interactions with the richness of
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`tour guide. This system replaces analog audio tapes with
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`computational information without isolating people from
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`random access digital audio. In addition, it adds a micro­
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`each other. The basic idea is to superimpose computer
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`computer and an invisible spatial locating device that
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`generated data on top of the real world, as the person
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`allow much more freedom for the participant.
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`moves within it. This idea was originally described by
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`Myron Krueger [4], but now a number of groups are
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`Permission to copy without fee all or part of this material is
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`granted provided that the copies are not made or distributed for
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`direct commercial advantage, the ACM copyright notice and the
`*Current address: bederson@cs.unm.edu,
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`title of the publication and its date appear, and notice is given
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`Computer Science Department, University of New Mexico,
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`that copying is by permission of ACM. To copy otherwise, or to
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`Albuquerque, NM 87131.
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`republish, requires a fee and/or specific permission.
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`CHI' Companion 95, Denver, Colorado, USA
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`© 1995 ACM 0-89791-755-3/95/0005 ... $3.50
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`210
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`

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`CHI' 95 MOSAIC OF CREATIVITY
`■ May 7-11 1995
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`Short Papers
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`The idea is to allow visitors to hear descriptions of pieces
`is described in [3]. For example, if the
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`digital objects
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`just by walking up to them. Descriptions may be heard in
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`computer noticed that the viewer had looked at several
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`any order, and can be cut short by walking away. Friends
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`pieces by one artist, it could offer extra background infor­
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`visiting together can stay in sync very naturally just by
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`mation on that artist. Or it could relate pieces currently
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`walking up to a piece at the same time. When they walk
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`being viewed to particular pieces that this viewer recently
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`away from a piece the description will stop and they may
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`saw. There could even be a "restroom button" on the
`talk amongst themselves.
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`device which would give the viewer directions to the
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`nearest restroom.
`Because the digital storage device can hold two and a half
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`hours of audio, the tour planner can describe many more
`One group [5] has created a similar technology, but in
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`pieces in the exhibit than any viewer will likely see. This
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`reverse, to identify the locations of individuals to a cen­
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`gives much more control to the viewer since they can
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`tralized computer system. In this system, people carry
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`hear descriptions of pieces they want to hear about.
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`around small infrared transmitters, and there is a single
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`receiver in the ceiling of each room.
`This prototype consists of a few devices that the viewer
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`carries with them: a random-access digital audio source
`Some museums have begun experimenting with new
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`(modified Sony MiniDisc TM player), a microprocessor
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`guide technologies, but they still have some limitations.
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`(Motorola M68332), and a custom infrared receiver that
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`One popular approach is to have some local audio broad­
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`tells the computer where the viewer is. A very small
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`cast technology so that each piece broadcasts a descrip­
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`infrared transmitter is placed in the ceiling above each
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`tion of itself in continuous cycles. The disadvantage of
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`piece to be described. It transmits a unique identifying
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`this approach is that participants often walk up to a piece
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`number that the computer uses to identify the location of
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`mid-way through a description. In this case, they hear the
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`the viewer. As the viewer walks around, the computer
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`second half first, and then the description starts over
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`simply controls the audio source to play or stop playing
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`again. It is vital that the user carry the audio source with
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`pre-recorded descriptions. See Figure 1 for a schematic
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`them so the descriptions can be heard on the user's time
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`diagram of the system.
`schedule.
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`CONCLUSION
`Augmenting rather than replacing the external world can
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`Transmitters
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`take advantage of computation without conflicting with
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`social concerns. We introduce a prototype museum tour
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`guide based on augmented reality which shows that more
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`appropriate technology can enrich our experiences with­
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`out interfering with our social interactions as much.
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`ACKNOWLEDGEMENTS
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`I am indebted to Jim Hollan. It was with him that I con­
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`ceived of this idea on a subway ride to New York City.
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`And I am thankful to Chris Calabrese who wrote much of
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`the software for the prototype.
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`Receiver
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`Microcontroller
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`REFERENCES
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`[l]Bederson, B.B and Druin, A. Computer
`Augmented Envi­
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`to Learn, Work and Play, ed. Jakob
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`ronments: New Places
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`Nielsen, in Advances in Human Computer Interaction,
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`Vol. 5, Ablex Press, In Press.
`[2]Communications of the ACM, Special Issue on Aug­
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`mented Environments, 36 (7), July, 1993.
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`[3]Hill, W.C., Hollan, J.D., Wroblewski, D. and McCandless,
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`T., Edit Wear and Read Wear, in Proceedings of Human
`Figure 1: Schematic of automated tour guide proto­
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`Factors in Computing Systems (CHI '92), ACM Press, pp.
`3-9, 1992.
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`[4]Krueger, M.W., Artificial II, Addison-Wesley,
`Reality
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`This type of technology offers the possibility of modify­
`1991.
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`ing the descriptions of pieces based on the particular
`[5]Want, R., Hopper, A., Falcao, V. and Gibbons, J., The
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`interaction history of this viewer with the exhibit. This
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`ACM Transactions on
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`Active Badge Location System,
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`notion, more generally referred to as history-enriched
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`Information Systems. Vol. 10 (1), pp. 91-102, Jan. 1992.
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`3:
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`Digital audio
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`type.
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