  Many researchers have developed VR systems for people with visual impairments
by using various audio feedback techniques. However, there has been much less
study of collaborative VR systems in which people with visual impairments and
people with able-body can participate together. Therefore, we developed a VR
showdown game which is similar to a real Showdown game in which two players can
play together in the same virtual environment. We incorporate auditory distance
perception using the HRTF (Head Related Transform Function) based on a spatial
position in VR. We developed two modes in the showdown game. One is the PVA
(Player vs. Agent) mode in which people with visual impairments can play alone
and the PVP (Player vs. Player) mode in which people with visual impairments
can play with another player in the network environment. We conducted our user
studies by comparing the performances of people with visual impairments and
people with able-body. The user study results show that people with visual
impairments won 67.6% of the games when competing against people with
able-body. This paper reports an example of a collaborative VR system for
people with visual impairments and also design guideline for developing VR
systems for people with visual impairments.
