During the last week of January 2022, I read several articles about a system that produced 3D sound tracking the movements of a tennis ball in motion. Action Audio transforms spatial data from the Australian Open’s real time ball monitoring technology into 3D sound.

This FAQ explains how the system works. The first item on the page is a documentary. Below that is a series of short video clips that demonstrate the individual sounds assigned to the ball as it moves across the court.

The sounds are:

• Blips increase in frequency as the ball approaches the court perimeter.
• A metallic bell/rattle sound indicates that the ball has been hit.
• High pitches identify forehand serves, and lower pitches correspond to a backhand serve.

The last clip includes the 3D sound and video from a previous tennis match. It is an “18 shot rally between Marin Čilić and Roger Federer in the fourth set of the Australian Open 2018 singles men’s final”.

The clip begins with the players hitting the ball back and forth. Then one player misses a shot. The crowd noise confirms my observation.

During the 2022 Australian Open, viewers could watch a livestream that included Action Audio overlaid onto the broadcast commentary.

Action Audio is a collaboration between Tennis Australia, Monash University and AKQA. The collaborators “thank the International Blind Tennis Association, Blind Sports & Recreation Victoria and the many sports fans who contributed to the co-design of Action Audio.”