During every Green Bay training camp, an inexperienced defensive lineman rotates in for a play or two, and quarterback Aaron Rodgers stifles a laugh. He glances at the Packers’ defensive line coach, Mike Trgovac, who knows precisely what Rodgers is about to do but is powerless to stop it.

Toward the end of his cadence, just before Rodgers calls for the ball to be snapped, he articulates the word “hut” with such gusto that the poor lineman bulldozes over the line of scrimmage, goaded offside by the N.F.L.’s leading expert in pre-snap subterfuge.

Just as valuable an asset as his arm strength, mobility and microprocessor of a brain is Rodgers’s voice, loaded with bass and thump and a tinge of soul. With it, he has coaxed eight neutral-zone infractions this season — including three in the first 21 minutes against Carolina last month — by using rhythm and inflection to exploit defenders’ aggressiveness, a tactic known as a hard count.

When deployed, it puts stress on the opposition, forcing players to ponder a challenge beyond merely trying to thwart the man who has been the league’s best quarterback for the past two months. It slows the pass rush, reveals potential blitzers and helps Rodgers decipher a defense, uploading critical data about its alignment and assignments.