The 21-year-old Russian let out a volley of shrieks and yelps as she played fellow Russian Alla Kudryatseva in the second round of Wimbledon.  Using a digital sound level meter, The Telegraph recorded maximum decibels of 103.2, louder than a motorcycle or a lawnmower.  She grunted loudly as she lost the first set, but her noisiest offering came as she served for the first time in the second set. Her opponent remained silent throughout, going on to win the match.  Last year, Sharapova broke her previous record of 102.7 – equivalent to an ambulance siren – by yelling at 103.7, greater than the noise of a small aircraft landing.  "It's difficult for me because I have been doing it since the age of four," she once said. "I don't necessarily like it when I watch myself on television but it's just automatic for me."  Normal conversation is registered at between 60 and 70 decibels and research has shown 115 decibels exceeds the human pain threshold.  There is a risk of hearing loss when noise is sustained at more than 90 decibels.  Spectator Jane Harris, 37, from Banbury in Oxford, said: "She really does shriek incredibly loudly, it must be so off-putting to play against."  Sharapova is known as the noisiest player on the circuit, followed by Serena Williams, at a much lower 88 decibels, and her sister Venus, at 85 decibels, the equivalent of a Harley Davidson.  A snow mobile and motorcycle both emit 110 decibels of noise, while a jet engine is 114 decibels. The highest sound possible is 194 decibels.  A violin registers between 82 and 92 decibels, while a French horn ranges from 90 and 106 decibels.  Grunting first became a problem in 1992, when Monica Seles let out a series of yelps and cries.  Her opponents complained that her shrieking meant they could not hear the ball and she was nicknamed "Moan-ica".  After reaching 93.2 decibels – equivalent to a diesel train - in her quarter-final match, she was ordered to keep quiet during her final against Steffi Graf, a match she subsequently lost.
Maria Sharapova is back to her old tricks, grunting at levels to match a    pneumatic drill.