Everything in the NFL feels different from field level, especially the noise. The contact is more violent, the timing of pass patterns crisper and the speed of the game practically a blur. However, the amount of volume that 78,106 people can summon in a steep-sided bowl such as FedEx Field radically changes a game. Especially a playoff game, such as the one the Redskins face next Saturday against a Detroit Lions team that thrashed them last month in the thunderous Silverdome.

The first words out of Coach Norv Turner's mouth yesterday, after a lopsided 21-10 victory over the Miami Dolphins, were: "Our fans were fabulous. . . . Maybe the 4 o'clock start helped." Then he grinned mischievously. The Redskins' first home postseason game in eight seasons also will start at 4:05, on Saturday. So whatever extra time Redskins fans need to "prepare" will be provided once again.

"Once the game started, I began to think about what this stadium is going to be like next Saturday," Turner said. "A month ago we went into Detroit and struggled with the crowd noise. We had a bunch of penalties because of the crowd noise. Now, the crowd is going to be on our side."

At the Silverdome, the Redskins had more than penalties--14 of them for 122 yards. In fact, the Washington offense was totally discombobulated by the dome din. Brad Johnson was sacked five times, fumbled three times and threw two interceptions, and his line was comically overwhelmed by Detroit's speed rushers. The Redskins also fumbled six times and generally played as though they were in shock. And maybe they were.

Casual fans might think home-field advantage in the NFL is some vague, psychological--and perhaps imaginary--advantage. Something that coaches babble about but that, in truth, has no tangible basis in football reality. If you ever sat as close as you legally can to the Redskins bench in their enormous new cavern of a stadium, you would never think so again.

Sitting in the third row of the stands behind the Redskins' bench yesterday was, at times, like being in an auditory maelstrom. Washington players on the sideline orchestrated the throng, waving their arms to turn up the crowd and quieting them with a simple tamping-down gesture with their hands.

The Dolphins' Dan Marino and Damon Huard couldn't hear themselves think at times. Their wide receivers couldn't hear audibles no matter how they cupped their hands to their ears. At peak crescendo on crucial third-down plays, even Miami's tackles--just a few feet from their quarterback--couldn't be sure they would hear the snap count. So they had to sneak a peek inward toward the ball, to see when it moved. In that slight twist of the neck, that inability to explode together on the snap, any offense's split-second advantage over the defense is lost.

That's just the way life along the line of scrimmage is in the NFL--if the home crowd really does its job. Sometimes, it seems turnover differential, the most crucial of all NFL stats, is directly related to decibel level. The more rattled team relinquishes the ball. In Detroit, the Redskins were on the short end. Yesterday, the Dolphins were in the turnover hole. As for penalties, Miami had six for 88 yards; the Redskins, just three for 25 yards.

The Redskins might need more than a crowd to handle the Lions. Washington didn't just get beaten, 33-17, on Dec. 5. "They wiped up the field with us in Detroit. . . . They kicked our butts. They wore us out," said veteran Irving Fryar, who gave the Redskins a 14-3 lead yesterday with a 30-yard touchdown pass from Rodney Peete on the second snap of the second half.

If Lions defensive end Robert Porcher torches 300-pound rookie tackle Jon Jansen like he did last month, all the crowd noise in the world might not help. Other Redskins linemen, including Pro Bowler Tre Johnson, also had their worst game of the season.

"Porcher is an unbelievable player. Their whole defensive line is quick and wants to get upfield as fast as possible and disrupt everything," Redskins tight end Stephen Alexander said. "But we got too keyed up for that game. We practiced all week in a gym with the noise blaring" to simulate the Silverdome.

Despite the licking the Lions gave them, the Redskins seemed extremely self-assured yesterday after their fifth victory in their last seven games. "You can't put a market value on the confidence it builds," Tre Johnson said of this 10-win season and a victory over a winning team, the Redskins' first of this entire season. "Now, we get to play at home. . . . It's not like RFK [Stadium yet]. We've moved to the mansion. . . . But we've got a pretty good house here. And better each week."

The FedEx Field crowd was fired up for this "meaningless" game. Still, if you turned around and looked at the individual faces in the crowd, you realized a strange thing. Even when the volume was highest, nearly half the fans were doing little or nothing to raise a ruckus.

"Next week, we want it to be the Lions who are getting off the ball late and [peeking] at the ball, not the man they're supposed to be blocking. We want it to be them, not us, who can't make their checkoffs at the line," said Fryar, the old-timer.

"Home field in the playoffs is a big advantage and we earned it. Now, it's important for the fans to know their role."

Back in RFK days, Washington crowds had the art of noise down to a science, perhaps better than any other NFL venue. Joe Gibbs and John Madden always said so. FedEx Field isn't so cozy or acoustically conducive to insanity.

However, yesterday's celebratory hubbub was a start. With 25,000 extra sets of lungs and 50,000 more hands to clap in the "mansion" than in old RFK, a reasonable facsimile of traditional Redskins madness should still be possible. All season, the Redskins have been under the gun. Next Saturday, we'll see how Redskins fans--after their long absence from the postseason--will react to playoff pressure.