Five different auditory displays were designed to aid blind users in finding objects in a virtual haptic 3d environment. Each auditory display was based on a different principle and incorporated different methods for representing spatial information. Results from an evaluation with seven visually impaired persons reveal to what extent these methods facilitate object localization in a virtual haptic 3d environment.

The needs of blind and visually impaired users are seriously under-investigated in CSCW. We review work on assistive interfaces especially concerning how collaboration between sighted and blind users across different modalities might be supported. To examine commonly expressed design principles, we present a study where blind and sighted persons play a game to which the former has an auditory interface, the latter a visual one. Interaction analyses are presented highlighting features of interface design, talk and gesture which are important to the participants' abilities to collaborate. Informed by these analyses, we reconsider design principles for cooperative interfaces for the blind.