Why tennis players make such a racket on court
Loads of tennis stars make their name at the Wimbledon tournament, but for some of them it's not always because they've played well.
In recent years, some players have been hitting the headlines for making too much noise on courting... by grunting!
Lots of players let out a moan as their racquet hits the ball, but now loads of people think it's gone too far.
Critics say it's really distracting for the other player and think there should be a rule banning grunts during games.
Last month, 16-year-old Portugese player Michelle Larcher de Brito was booed off court by the crowd at the French Open, but she's not the loudest player around.
That honour goes to Maria Sharapova, whose gigantic grunts measure a whopping 101 decibels - that's as loud as a lion's roar!
So what makes players grunt? And how come some are so much louder than others?
James Lowther is a sport psychologist, which is a doctor who helps explain how sports people's minds work.
He said there's a controlled release of pressure when any player breathes out as they hit the ball, which makes a slight noise.
"What's happening is that some people have exaggerated the noise as they breathe out and therefore you get this grunting process that goes on.
"They do need to breathe out as they strike the ball, that's good basics in tennis, but we've got a situation of whether or not it's becoming very unsportsmanlike or it's going to distract your opponent, so that's where the issue is."