Pros vs. Joes is a relatively common sporting device–retired professional athletes square off against capable amateurs in a test of athletic skills. But what happens when the Joes in such a pairing also happen to be visually impaired? Swedish agency Åkestam Holst leveled that seemingly uneven playing field with the Pepsi-funded project, The Sound of Football.

The Sound of Football paired one team of former football pros with another team made up of visually impaired players, and fitted them both with equipment that allowed them to hear, rather than see, what was happening on the playing field around them. The agency hopes that the technology developed for the project will help the visually impaired off the pitch too.

The Sound of Football is part of the Pepsi Refresh project, a 2010 campaign created out of TBWA/Chiat/Day Los Angeles that encourages and funds innovative ideas. The campaign rolled out to more than 25 countries this year.

Via the Sound of Football project, Akestam Holst fitted each player with a blackout visor and a mounted iPhone that fed them audio cues as to where other players, the ball, and the goals were. Created along with creative technology company Society 46 and using 3-D camera technology from Tracab, the project aims to give visually impaired football players a more intense sporting experience using tracking technology and sound, says Åkestam Holst creative director Martin Cedergren. “We want to show that everyone can realize his or her dreams, even if you happen to be young with a disability.”

To make this ambitious idea work, Society 46 used the same tracking technology that was used during the 2010 FIFA World Cup to position each player in real time on the football pitch. Sixteen cameras were placed across the pitch at Stockholm’s Söderstadion and captured data on the location of everyone on the field. Exact positions and geometrics were extracted and fed into an iPhone application that converted the data into binaural 3-D sound, which gives players a sense of distance. Through headphones each player can hear what’s happening around them: A bell rings as a player approaches the ball, a cymbal means they’re close to the net, and a thumping drone signals an incoming player. To position sounds within the 3-D environment, developers used FMOD–a programming library for the creation of interactive audio, used in games such as Guitar Hero and World of Warcraft. And player rotation detection was powered by the iPhone’s gyroscope and internal compass, making the entire sound landscape change.