Spurred on by Icelandic songstress Bjork, crowds at the London 2012 Paralympics are keeping a lid on their excitement for blind sports that need to be played in silence.
At the goalball, five-a-side football and blind jumping events, spectators have had to stay quiet to allow competitors to hear the ball or their coaches' instructions.
The 6,500-seater Copper Box venue was dubbed the "box that rocks" during the Olympic handball, with its intimate nature and pumped-up fans making for a noisy atmosphere.
But it is now a place of reverential hush, invoked by the playing of Bjork's "It's Oh So Quiet", with all its "Shhhh" sounds, to encourage the crowd to settle down for the goalball.
"We have to focus purely on sound, so that means we pick up on everything. So we have to concentrate," said Canada's Brendan Gaulin, after a 5-4 win over South Korea.
"For the first goal there was definitely a baby crying in the corner and it made it tough to stop that shot."
The three-versus-three sport, played with two giant goals at each end, sees players roll a ball with two bells in it. The defending players react to the sound and try and keep the ball out.
Belgium's Glenn van Thournout said the hush spreads quite easily.
"Humans are flock animals. If the person next to you is silent then you stay silent," he said.
Meanwhile across at the Riverbank Arena, the crowds at the blind five-a-side football are urged to let rip during breaks in play but button it during play.
Fans are told it's their "last chance to make maximum noise" before a match kicks off.
The crowd are whipped up as the players come out to the driving sound of Led Zeppelin's "Kashmir", and cheer heartily as the players are introduced, before falling silent. Buses can be heard trundling along a service road behind.
The sport is played with a rattling ball and while the four outfield players are visually impaired and wear eye shades to ensure fairness, the goalkeepers may be fully sighted.
Players shout the word "voy" to indicate where they are. At set pieces, coaches tap the posts so they know where to aim.
"We could feel the support as we walked into the arena and even all the way throughout the game," said Great Britain's Daniel English.
"We could tell they wanted to make noise but that's a natural reaction as a player is coming in to shoot. It's different coming to blind football where you cannot have chanting all the way through.
"It's a new experience and, obviously, they are learning as much as we are but we don't mind that."
Even at the normally raucous Olympic Stadium, the hush is catching on.
The 80,000-seater venue fell silent for the men's F11 long jump final, in which athletes with little or no vision take off aided only by the sound of their coaches' calls.
After lining up their athlete straight on the runway, the coach stands at the take-off board, clapping a running rhythm and calling to their athletes so they can hear the distance to the line. They then jump out of the way at the last second.
At the football, French judo player Sandrine Martinet, who won silver in Athens 2004 and Beijing 2008, said she was getting the hang of the stop-start audience participation.
"It's so frustrating to be unable to cheer during the match," she said.
"But when there's a break in play, we're hollering."