PALM BEACH, Fla. — Taking another technological step forward, NFL owners approved a communication device for defenses today.

One defensive player will wear a helmet similar to what the quarterback is allowed on offense. Should that player leave the game, a teammate can be designated to also have the device. But only one defender with the device can be on the field at a time.

"We want to safeguard against a situation with two players on the field at the same time with the helmet communication," said Atlanta Falcons president and competition committee co-chairman Rich McKay.

"We are talking about a three-down player, perhaps a linebacker who doesn't come off the field," added Tennessee Titans coach Jeff Fisher, the other co-chairman of the committee that recommended instituting the device. Fisher has just such a player in Keith Bullock.

"In the event he goes down because of an injury, we'd identify our backup player as another three-down player."

Fisher noted this change won't eliminate entirely the need for signals from the sideline, something that pretty much has disappeared for offenses.

"The defense will still have need to signal in a hurry-up situation, where the ball is snapped very early," he said.

The vote was 25-7 in favor — 24 yes votes were required — and all seven negatives came from head coaches with offensive backgrounds.

Voting against the measure were Seattle (Mike Holmgren), Tampa Bay (Jon Gruden), Oakland (Lane Kiffin), Philadelphia (Andy Reid), St. Louis (Scott Linehan), Washington (Jim Zorn) and Green Bay (Mike McCarthy).

New England coach Bill Belichick, whose involvement in the Spygate scandal that included taping opposing coaches' defensive signals made the communication device a hotter topic, voted for the proposal.

"I've been for that ever since the thing with the quarterbacks came out," Belichick said. "The problem is just how to do it. The concept of it is fine, but the logistics of it are a little bit of a different story. You don't always have a quarterback in the game on defense, like you do on offense. It's a little bit of a different setup.

"There is a substitution issue. Even the way it's proposed now if you have a middle linebacker like Brian Urlacher or Ray Lewis, or somebody like that who played on every single play on defense as kind of the equivalent of the offensive quarterback, then that's one thing. A lot of teams don't have that, and I'd say we would fall into that category."

The owners also tabled discussion of a rule banning a player's hair from flowing over the nameplate and number on the back of the uniform.

Mike Pereira, NFL VP of officiating, said there were 92 reversals on instant replay challenges last year, representing 38 percent of the total coaches' and booth challenges. That was up from 34 percent in 2006 and 31 percent in 2005.

"My concerns are when the number of reversals goes up," Pereira admitted. "We take a look at that, where the number is going up."

Pereira also wondered if the "level of respect has gone down" between players, coaches and game officials. He cited several instances where players either got into shouting matches with officials or, in Baltimore, when Ravens linebacker Bart Scott picked up a penalty flag and tossed it through the end zone after disagreeing with a critical late call in a loss to New England.

"We have to work not to get in those situations," Pereira said. "I agree both sides are at fault.

"We'll spend more time in training camps and before games talking to players, get involved before it gets out of hand."