Getty Images

Seahawks fans will try to set a Guinness world record for the loudest crowd at a sporting event when the team hosts the 49ers on September 15, but their bid may not wind up being the only one at an NFL stadium this year.

A group of Chiefs fans started a Facebook group called “Terrorhead Returns” to rally support for Guinness to monitor the level of crowd noise at a Chiefs game during the 2013 season. The group aims “to re-affirm and establish our long known history” of loud crowds at Arrowhead Stadium.

As the Kansas City Star points out, an attempt at Arrowhead would come with more than 12,000 additional voices in the mix than the Seahawks can muster at CenturyLink Field if the stadium is full. There’s no date set at this point for an attempt, although the Chiefs fan group reports that Guinness has received their application and notified the group that it passes muster for the first phase of the acceptance process. It will be a few weeks before they learn whether there will be an official attempt at the record.

The current record belongs to a crowd at a Turkish soccer game, which reached 131.76 decibels during a game. That stadium is considerably smaller than CenturyLink Field, which would seem to offer the NFL fanbases a good shot at the record if they can rally every available voice to their cause.