The Prestbury Park roar, when thousands of racing fans cheer their favourites towards the finish line, is well known, but this week it could be crowned the loudest noise in the sporting world.

The current Guinness World Record for a sporting crowd is held by Liverpool fans, measured at a staggering 130.7 decibels, recorded against Chelsea in 2005.

Betting giants William Hill are rigging up a sound level meter at the front of the grandstand at Cheltenham this week to monitor just how much noise the 55,000-strong racing crowd can make each day.

During this year's Carling Cup final between Manchester United and Spurs, the were measured at 100 decibels during the match, and now Hills are betting that racing fans can roar home their winners a lot louder.

Kate Miller, spokeswoman for Hills, explained: ''Football fans may chant and cheer, but Cheltenham's racing fans can produce a spine-tingling noise when roaring home their fancies. The 'country chorus' definitely know how to make their appreciation known and we hope that racing can give football a run for its money.''