The "Hampden Roar" is as loud being right next to a roaring lion and almost as deafening as a jet engine taking off, according to a study at Sunday's Scottish Cup semifinal.
Sound experts recorded a peak noise of 115 decibels during Celtic's 4-0 victory over Rangers at Glasgow's Hampden Park.
The noise dwarfs levels recorded during a Press Association Sport study of Premier League grounds in 2014, which found Old Trafford topping the list at a peak of 84 decibels.
The results, recorded by Vanguardia and issued by Hampden Park, found the peak noise came after each Celtic goal. The noise made by 49,729 fans when the teams came out of the tunnel hit 109 decibels.
A media release stated: "The peak level is equivalent to the roar of a real lion from less than a metre away, as loud as the front row of a music concert and just short of a jet engine at take-off from 25 metres."
The atmosphere during the— Hampden Park (@Hampdenpark) April 17, 2018
Celtic 🆚 Rangers @ScottishCup semi-final on Sunday was absolutely fantastic!
The Hampden Roar on Sunday scored a UK high of 115 decibels!
Read more here:https://t.co/AmFyEMx88q pic.twitter.com/1tyTWHd9kl
Matt McIlroy, senior acoustic consultant at Vanguardia, said: "The noise levels from the moment the players walked out on to the pitch were incredible and really shows the passion of the fans that those levels did not significantly change throughout the match.
"It's also worth noting that these levels were registered trackside: imagine how loud it would have been in amongst the fans."
The Guinness Book of Records states that the loudest registered crowd roar at a sports stadium was 142.2 decibels by supporters of American Football side Kansas City Chiefs in 2014.