Subtle audio feedback creates a sophisticated interface for blind video game players
The cars in 2017 racing-simulator Gran Turismo Sport are rendered in exquisite detail, right down to 3D heater vents inside the player’s vehicle. Lighting and reflections on the cars and environment simulate the specular properties of each material on screen. Headlights recreate the exact output of their real world counterparts, coming together for one of the most realistic looking racing games ever made.
And it’s all a waste for gamers like Edis Adilovic.
It’s not that Adilovic is a die-hard Forza fan, or only likes the silliness of Mario Kart, but that he’s blind. That doesn’t mean he doesn’t enjoy car racing games though. There are a handful of racing games that have been developed to include audio-based feedback for vision-impaired players, such as Mach 1 and Top Speed. However, the experience was slightly lacking compared to what sighted players can enjoy, which is where Brian Smith’s racing auditory display (RAD) comes in.
RAD is a system that gives players positional feedback through sound cues alone. The player is best off wearing headphones so that the audio has good stereo separation, as judging how far a sound seems to be coming from the left or right is key to the experience. When a car is getting closer to the left edge of the road, the engine noise will slide to the left, and vice versa. As the player approaches a curve, a turn number is announced, followed by a series of tones heard from the left or right to give players a sense of how far they are through a turn. It may sound simplistic, but these systems communicate a lot of nuanced information to the player, giving them more autonomy over how they play.
Instructions versus information
Previous driver assistance systems in games essentially turned driving games into reflex tests. They would often dictate explicit instructions to the player, such as “turn left now,” which meant that players could only try to hold steady until it was time to react to the next command. Players then had very wobbly-looking routes through a track, and reported that it wasn’t a whole lot of fun. Since developing a sense of mastery is a big part of why video games can be satisfying, there was a lot of room for improvement in previous audio interfaces.
By those metrics, RAD seems to be a considerable improvement, as blind players end up driving their cars on nearly the same routes as sighted players, as they’re able to use their location feedback to make choices about where they want to align their cars, rather than just react. Announcing turn numbers lets players learn a course over time, eventually figuring out which corners can be cut to improve lap times. Once acclimated to the system, blind players using RAD were able to achieve times comparable to casual sighted players. Even more importantly, testers like Adilovic reported having more fun playing with RAD, finally getting the sense of empowerment video games offer most people all the time.
Add-on interface
RAD is still in development at Columbia Engineering, and currently only runs on a custom 3D game used for testing purposes. However, it’s being built as a modular player interface that can be added to other games. Ideally, developers of major titles will be able to simply add it as an accessibility option for blind players, greatly expanding the number of titles those gamers can play. Once the racing interface is figured out, Smith plans to take the same audio concepts to other genres of games, since they should be enjoyable even if people can’t see every detail rendered on the screen.
Source: For blind gamers, equal access to racing video games by Columbia University School of Engineering and Applied Science, Tech Xplore
