Current Wimbledon champion Maria Sharapova has broken her own record with the loudest 'grunt' on court.
An unofficial 'gruntometer', belonging to a newspaper, recorded her noise at 101.2 decibels - that's almost as loud as a police siren!
Other players have complained about Sharapova's grunting in the past, saying it puts them off their game.
But the star said: "I don't pay any attention to that and I never have and I probably never will."
Serena Williams, who's also known for her loud grunting, also stuck up for the tennis trend.
"I am going to carry on grunting. It's not my business to control what people think," she said.
But the loud noises on court have led to complaints from high up in the tennis world too.
Wimbledon referee Alan Mills said he wants to crack down on grunting and has asked coaches to speak to their players.
"I think the message is getting through," Mills added. "But the grunting has got progressively worse over the years. I would really like it curbed."