NFL umps had worn live microphones mainly to let viewers listen to snap counts. But with umps farther from quarterbacks, the NFL lets centers be miked live — with the NFL turning mikes on after huddles and off after snaps.

Although players have long been miked for taped programming, this marks the first time they're being miked live on a regular basis.

Fox had its announcers briefly stay quiet during Sunday's Green Bay Packers-Philadelphia Eagles game — it also had the mikes at the Carolina Panthers-New York Giants game — to let viewers listen in. Said Fox Sports President Eric Shanks: "The calls at the line are unbelievably crisp."

CBS had mikes at the Cincinnati Bengals-New England Patriots game — only the Bengals center agreed to wear them — and eventually, said CBS production vice president Harold Bryant, CBS "might try to roll them out" to more than one game a week. And, suggested Fox's Shanks, the surveillance could expand: "The NFL will work with us to see if other players might be miked."