"But the club would intervene if it was felt the noise was liable to give the player an advantage over their opponent, or to the extent that it was distracting other players."
Sharapova is hardly alone in grunting. Our survey of Wimbledon players found she was run a close second by Serena Williams, the defending champion, who hits 77.6 decibels.
Unexpectedly, a relatively unknown British player, 20-year-old Anne Keothavong, was next with a loudest grunt of 72.
And Croatian Karolina Sprem, 19, managed 68.3. Tim Henman managed a paltry 61.6 decibels - which may explain in part why he crashed out of Wimbledon yesterday in a straight-sets defeat to Mario Ancic of Croatia.
The grunting debate divides the tennis world. Jeremy Cross, tennis coach at Loughborough University in Leicestershire, said: "Grunting is a useful way of exhaling and when we exhale we relax our muscles."
But sports psychologist Dr Matthew Pain said it did not help the players perform any better. "There is no physiological basis for it. In many cases it could be that the player is using it to gain advantage."
And even at 86.3 decibels, Sharapova has some way to go to beat the all-time record holder: former Wimbledon champion Monica Seles is grunter extraordinaire, hitting 93.2 decibels 11 years ago.
