Audio system allows visually impaired gamers to compete

Dubbed racing auditory display (RAD), the system enables them to play with the same speed and control that sighted players experience.

The audio-based interface, which works on a standard pair of headphones, can be integrated by developers into almost any racing video game, making a popular genre of games equally accessible to those who are blind.

“The RAD is the first system to make it possible for people who are blind to play a ‘real’ 3D racing game – with full 3D graphics, realistic vehicle physics, complex racetracks, and a standard PlayStation 4 controller,” said Brian Smith, who led the project.

“It’s not a dumbed-down version of a racing game tailored specifically to people who are blind.”

While there are a number of games on the market suitable for the blind, many are loaded with competing sources of information that players must sift through, slowing down the fun of playing the game. Others are versions of popular games so simplified that a blind gamer does nothing more than follow orders.

There has been a fundamental trade-off between preserving a game’s full complexity and its pace when making it blind-accessible.

“Our challenge,” said Smith, “was to give visually impaired players enough information about the game so that they could have the same sense of control and thrill that sighted players have, but not so much information that they would get overwhelmed by audio overload or bogged down in just figuring out how to interpret the sounds.”

Smith’s work builds on two distinct areas of research: building audio navigation systems and developing blind-accessible racing games and driver assistance systems.

The RAD comprises two novel sonification techniques: a sound slider for understanding a car’s speed and trajectory on a racetrack, and a turn indicator system for alerting players about upcoming turns well in advance of the actual turns.

Together, these approaches enable players to understand aspects about the race and perform a wide variety of actions in a way that is not possible in current blind-accessible racing games. Smith’s aim was to design an interface that would give players enough relevant information to form a plan of action.

“The RAD’s sound slider and turn indicator system work together to help players know the car’s current speed, align the car with the track’s heading, learn the track’s layout, profile the direction, sharpness, timing, and length of upcoming turns, cut corners, choose an early or late apex, position the car for optimal turning paths, and know when to brake to complete a turn,” said Smith.

Smith designed the RAD and then built a prototype car racing game in popular game engine Unity, and integrated the RAD into that prototype.