The strange new soundtrack now playing inside designated NFL defensive players' heads dazed Dansby when defensive coordinator Clancy Pendergast's voice boomed from his helmet early in training camp.

''The first time I tried the radio helmet, it was so loud everybody could hear the call in our defensive huddle but me,'' Dansby says with a laugh. ''They had it turned up so loud because we play in noisy stadiums.

''I told the guys on the sideline, 'You've got to turn it down!' ''

This summer, ''Can you hear me now?'' isn't just a cell phone commercial slogan.

It's the recurring question defensive coordinators and players have been asking during their adjustment to the league's biggest offseason rules change - the coach-to-defense radio communication system.

''I say to Karlos after signaling in each play, 'Raise your hand if you can hear me,' '' Pendergast says.

Select defensive players, usually a linebacker or safety chosen by the coaching staff, can thank Spygate for their new headgear.

Those defenders join quarterbacks as the league seeks to counterbalance the New England Patriots' illegally videotaping of the New York Jets' defensive hand signals in last year's season opener.

The NFL fined coach Bill Belichick $500,000 and the Patriots $250,000, stripping the club of a first-round draft choice for violating its rules on videotaping opposing teams from the sideline, a practice Belichick admitted dated to the 2000 season.

''It's going to speed up the whole process,'' San Diego Chargers coach Norv Turner says. ''And it takes away that threat of someone stealing your signals, which is big now.''

The new communication system passed by a 25-7 margin at the April owners meetings after failing by two votes in 2007.

''The feedback is almost universally positive,'' league executive vice president of football operations Ray Anderson says. ''Defensive coaches are saying, 'We've leveled the playing field. It will give us the ability to do some coaching on the field.'

''The offensive geniuses are going to have to put their thinking caps back on.''

How will offenses adjust?

Indianapolis Colts coach Tony Dungy foresees offenses changing personnel groupings after the offensive and defensive headsets shut off with 15 seconds left on the play clock. There might be more audibles and up-tempo play-calling.

''On the flip side, are we hurting ourselves by not getting lined up, not getting motion, not getting exactly what you want in watching the play clock?'' Panthers quarterback Jake Delhomme says.

Offensive coordinators have been able to talk to quarterbacks since 1994. Yet after years of relying on hand signals and color-coded wristbands, defenses are adapting to a device that seems to be spun off of George Orwell's ''1984.''

Big Brother is talking to you.

''It's like being inside the coach's brain,'' Dansby says. ''It's cool. The coach can give you what he's thinking in your headset and you can play even faster.''

Head of security

The preseason has been a four-game laboratory for breaking in the Motorola's transmission hardware. The primary defender will have one ''live'' helmet on the field and a second wired helmet secured in a trunk in case of malfunction.

A designated backup player also will have a ''live'' helmet stored in the container in case of injury to the primary player, along with two spare battery packs. The system costs $28,000 per team.

There are 268 million different military-grade encryption codes protecting the frequencies.

''You never say never,'' Anderson says. ''But we think it's virtually impossible to tamper with.''

A league-appointed monitor will stand sentinel on each sideline over the dual backup helmets stored in a secure, 3-by-4-foot trunk that is off-limits to players, coaches and club personnel.

''We want to make sure there's no inadvertent mistakes with using the helmets,'' Anderson says.

Ninety minutes before each game, the defense must designate one primary and a backup player authorized for receivers in their helmets. Only one ''live'' helmet can be on the field at a time.

Failure to notify the umpire of any change because of injury or strategy will result in a 5-yard penalty for illegal substitution.

The primary defender with the live radio is designated by the same small green dot on the back of his helmet as quarterbacks wear.

Coaches have 25 seconds to make a call and pass on any alerts when the play clock begins to tick down from 40 seconds to when microphones for all the radio transmitters shut off automatically at the 15-second mark. The Dallas Cowboys had a strategy in mind when designating linebacker Bradie James as their primary radio head rather than safety Ken Hamlin.

''Say the offense has three wides and the safety gets run off way down the field on a deep route,'' defensive coordinator Brian Stewart says. ''Now he has to sprint back to the huddle and tell everybody what the call is. The linebacker is more often around the middle of the field.''

Still some glitches

Despite the devices' popularity, there have been glitches.

Defensive coordinator Ted Cottrell of the Chargers and Mike Zimmer of the Cincinnati Bengals conceded they wound up talking to themselves when they thought they had called in the signal.

''The one thing I have to get used to is pushing the button,'' Cottrell says of the trigger on the radio attached to his belt. ''The preseason is a time to get the bugs out.

''But the defensive headset is something we needed a long time ago to even things out.

''One of the big things is the players get the signal maybe two or three seconds earlier.''

Miami Dolphins linebacker Channing Crowder would appreciate calmer and clearer communication from excitable defensive coordinator Paul Pasqualoni.

''It scares the hell out of you sometimes because Pasqualoni is not the calmest guy in the world,'' Crowder says. ''He gets to yelling in there every play. He'll say, 'Watch the run! Watch the pass! Watch it!'

''What else can I do? It's run or pass.''

Tennessee Titans linebacker Keith Bulluck has run into a slightly different problem.

''One play I was still on the ground after making a tackle and (Titans defensive coordinator Jim Schwartz) was already talking to me,'' Bulluck says.

Whatever the difficulties, the in-game advantages are obvious. Carolina Panthers linebacker Jon Beason says the system will prove to be most helpful during two-minute, hurry-up situations.

Pendergast has taken a more conservative approach.

''I've been coaching all offseason as if we weren't going to have it,'' Pendergast says. ''That way, the players aren't depending on it in case it goes out in the second quarter. We'll have contingency hand signals.''

Some others have more pressing concerns.

''Giving it to the linebackers, is it going to stand up?'' Jacksonville Jaguars linebacker Mike Peterson says. ''I'm banging my head constantly. The quarterback is rarely hit.''

Bengals middle linebacker Dhani Jones had a different take on the NFL's newest innovation.

''I hear voices in my head all the time,'' Jones says. ''I'm used to it.''