A guy built a speaker into a regular tennis ball that makes distinctive moans every time it's hit with a racket. Now players don't even need to make noise during a match — the ball itself will take care of the rather unusual soundtrack.
A guy built a speaker into a regular tennis ball that makes distinctive moans every time it's hit with a racket. Now players don't even need to make noise during a match — the ball itself will take care of the rather unusual soundtrack.