Answer: People who are blind.
There are currently a number of racing video games designed specifically for blind people, but Columbia University computer science Ph.D. candidate Brian A. Smith thought they fell short of delivering a truly enjoyable experience. So he decided to build an interface that blind people could use to play any pre-existing racing game.
Many racing games for the blind deliver an overwhelming amount of information through the audio system, or just give the player instructions on what to do next, taking the fun out of it. Smith’s technology, called RAD (racing auditory display), relies on a simple set of auditory guidance systems. One uses a sliding tone to indicate the speed and trajectory of the car, while the other notifies the player of approaching turns with directional sounds.
“The RAD is the first system to make it possible for people who are blind to play a 'real' 3-D racing game — with full 3-D graphics, realistic vehicle physics, complex racetracks, and a standard PlayStation 4 controller,” Smith told New Atlas. “It's not a dumbed-down version of a racing game tailored specifically to people who are blind.”