Sotto Voce: Exploring the Interplay of Conversation and Mobile Audio   Spaces
  In addition to providing information to individual visitors, electronic guidebooks have the potential to facilitate social interaction between visitors and their companions. However, many systems impede visitor interaction. By contrast, our electronic guidebook, Sotto Voce, has social interaction as a primary design goal. The system enables visitors to share audio information - specifically, they can hear each other's guidebook activity using a technologically mediated audio eavesdropping mechanism. We conducted a study of visitors using Sotto Voce while touring a historic house. The results indicate that visitors are able to use the system effectively, both as a conversational resource and as an information appliance. More surprisingly, our results suggest that the technologically mediated audio often cohered the visitors' conversation and activity to a far greater degree than audio delivered through the open air. 
Paul M. Aoki, Rebecca E. Grinter, Amy Hurst, Margaret H. Szymanski,   James D. Thornton, and Allison Woodruff