Update: As James Hamilton points out, it's actually Alan Shearer making the noise with his mouth. Call off the flatulence police.
During Match of the Day's analysis of Norwich's victory over Man City on Sunday night it sounded very much like one of Alan Hansen, Alan Shearer or Gary Lineker let one rip, quite loudly.
The chief suspect would appear to be Alan Hansen who seems to make an attempted cover up by laughing. Either that or he was expressing amusement at one of the other's flatulence problem.
H/T Will Hamilton