Herm Edwards breaks down how the Rams' defense can control Aaron Rodgers and get a win against the Packers. (1:43)

EARTH CITY, Mo. -- St. Louis Rams defensive end William Hayes was sitting in a team meeting room early Wednesday morning, watching film and minding his business, when suddenly he jumped out of his compression boots at a loud and annoying sound going off behind him.

When Hayes turned to see who or what had intruded in such a rude way, he saw coach Jeff Fisher standing there with an air horn in hand and a smile on his face.

"We were in there looking at film and he brings the air horn in there," Hayes said. "I was in the boots, getting my legs right, and he comes in there and the first thing I did was I jumped offside then. That might not be a good sign for me. I guess that was a sign telling me I need to be a little more disciplined."

In other words, Fisher's message was received -- very loud and very clear.

As though the undefeated Green Bay Packers and all-everything quarterback Aaron Rodgers didn't present enough of a challenge for the Rams this week, Rodgers' knack for drawing defenses offside and then stealing big chunks of yards on free plays is a dangerous proposition for a Rams defense that has jumped offside an NFL-high 36 times (with 20 accepted) since Fisher arrived in 2012.

Which is why Fisher this week is making sure his defense, particularly the line, is focused at all times. The air horn was the most noticeable new tactic Wednesday; Fisher also used it in practice, walking up behind each lineman during a rep and blowing the horn in their ear.

"That's just a message to the D-line on the hard count," Fisher said. "No one uses the hard count better than Aaron. ... He pulls them offside two or three times a game. So I woke them up in their meeting room this morning with the horn, just to send a message."

For the record, that message wasn't all that welcome.

"No, some were pissed," Fisher said, laughing. "It scared them."

The Rams don't just have to worry about Aaron Rodgers' arm, legs and brain. His voice will be an issue, too. Jamie Squire/Getty Images

A startling noise pales in comparison to what Rodgers can do if he can coerce a defender into jumping across the line. Rodgers has drawn a league-high eight offside flags through the first four weeks. The 5-yard penalty is one thing, but what Rodgers does when it happens is the bigger concern. On those eight plays, Rodgers is 5-for-5 for 164 yards and two touchdowns, good for a perfect 158.3 passer rating and 100.0 QBR.

As ESPN Packers reporter Rob Demovsky explained last week, the second Rodgers notices a player jumping early, it turns into sandlot football and he looks to find a big play, knowing there are no repercussions if he makes a mistake. Which is why six of the eight offside penalties Rodgers has drawn this year have been declined -- sometimes because Rodgers has completed a pass, sometimes because it led to another penalty worth more than 5 yards.

Every team that plays Green Bay says similar things to what is coming out of Rams Park this week, yet Rodgers still has success with the cadence. Rams linebacker James Laurinaitis says one way to combat Rodgers' plan is to just keep going if you do jump offside, knowing that the officials will blow the play dead so the quarterback doesn't take an unnecessary hit.

"I think the natural reaction is, 'I don't want to get caught,'" Laurinaitis said. "But just go touch him, get around the corner and make them blow it dead."

Short of that, the Rams are trying all they can to prepare for Rodgers' varied cadence. Fisher hasn't piped in crowd noise for practices since arriving in St. Louis, but he has been blaring music at practice all week. At Wednesday's workout, the eclectic playlist ranged from James Brown to Coolio to Van Halen to Blackstreet. Players took the field to the "Macarena."

"We're just kind of substituting crowd noise for a little bit of music and get them to focus a little bit," Fisher said. "So it's been good, and rather than turn it off when the defense goes on the field, we just left it on. The defense can communicate through it too. So it worked for us last week.

"When the guys were walking out and the 'Macarena' was playing, none of them had heard it before. They weren't born."

Jeff Fisher is using some unorthodox methods to get his team ready for Aaron Rodgers. Scott Rovak/USA TODAY Sports

Backup quarterback Case Keenum, who takes the bulk of the reps with the Rams' scout team, is the man charged with playing the role of Rodgers. He spent some time watching Rodgers on television and tried to pick up any tics or cadence variations that might give the defense a sense of what to expect on Sunday.

"It's hard to replicate anything Aaron Rodgers does," Keenum said. "That's why he's Aaron Rodgers and I'm not.

"He's literally stealing yards. As a quarterback, you have to admire what he can do and his mannerisms and how he controls the offense. It’s impossible to replicate exactly how, but we do it as best we can."

When the Rams and Packers last met in the regular season in 2012 -- a 30-20 Green Bay victory -- Rodgers drew the Rams offside twice. The results were predictable: He completed both passes for 91 yards and a touchdown.

Hayes was reminded of that on Wednesday, shaking his head and marveling at how long Rodgers has been able to work his magic.

"It's all about trying to be disciplined and stay onside," Hayes said. "As simple as that sounds, we're just trying to stay onside. He has a hard count that will draw you off; it's pretty easy for him to draw you off. You are thinking he just went through a cadence and then he has to go on this one, and then he goes 'Hut' and you go. So you've got be disciplined."

Easier said than done.