Those are blind people. The ball has little holes for a beeper (used to be a bell) inside the ball. There are other sound signals around the court to locate the goal posts and boundary lines, keep the players oriented. They have to roll the ball, not throw.
So, while it looks dumb, for the blind it probably sounds awesome.
LOL. Thanks for explaining. Makes a little more sense now.
Maybe they can start a Dodgeball League for them next. Or Bowling. 😬