The game took place in Las Vegas. The sounds were imported from Oakland.

No fans yelled from the seats of Allegiant Stadium Monday night as the Las Vegas Raiders triumphed in their home-team debut over the New Orleans Saints. Still, Raiders die-hards were heard. Viewers of a special broadcast of “Monday Night Football” seen on ABC and ESPN could listen to cheers, crowd excitement and more. The National Football League offered up the sounds of Raiders supporters from the players’  previous home, the Oakland Coliseum.

Plenty of sports leagues and TV networks have been happy to pipe in some sort of crowd sound to fill the low-fi ambience of games played during the coronavirus pandemic. The NFL, however, isn’t just looking for noise. The league also wants a signal. So it has created sound modules based on the endemic noises at each of the stadiums that host its football teams, and hired operators to dial up the appropriate aural fan demonstration for all of its TV partners.

“This is more authentic,” says Vince Caputo. As the supervising sound mixer at NFL Films, he knows the real timbre of a football fan.  Other leagues may allow “canned stuff or stuff from video games,” he says, but the NFL believes in the power of “really very, very natural sound.”

That’s probably because the NFL has been collecting crowd sounds from Foxborough’s Gillette Field, Green Bay’s Lambeau Field and New Orleans’ Mercedes-Benz Superdome, among other venues, for the past seven years. In 2019, Caputo’s team went back out to stadiums to fill up on sounds not previously collected, including crowds in facilities that may not have been extant when the project first started. Collecting stadium noises was originally conceived as a way for the league’s NFL Films division to “build up our library of crowd sounds for production, so whenever the NFL had this need, we had a ready resource we could tap into.”

The league really had a need this year.

So has anyone hoping to present a big-audience game in recent months. The spread of the coronavirus pandemic scuttled live sports for weeks, and the nation’s big leagues have had to scramble to keep on playing. Some of their efforts have been spent on ways to re-create big-field atmosphere when few if any fans can gather at most stadiums, fields and rinks. The National Basketball Association placed microphones strategically around the courts of ESPN’s Wide World of Sports near Disney World, where all its matches are taking place. Those devices are meant to enhance the sounds of sneaker soles on the court and the bounce of a basketball. Meanwhile, Major League Baseball offered up a collection of 75 different sound effects and fan reactions from audio files contained on Sony’s “MLB: The Show” videogame.

The league has good reason to give its pandemic games a few familiar touches. At a time when TV networks have been left unable to produce many of their scripted dramas and comedies in timely fashion, football games are shouldering a heavy load. Media companies like Comcast, Walt Disney, ViacomCBS and Fox are counting on NFL broadcasts to bring in the big audiences advertisers say they need and for which they pay some of the medium’s highest prices.

NFL executives felt they had something that could at least give home viewers some of the actual stadium sounds to which they were long accustomed. Doing so hasn’t been easy, Caputo notes.

For the sounds to work, they must be stripped of any audio elements that might take people out of the game they are currently watching. That means staffers have to remove any voices over a public address system talking about old scores or music indicating a specific kind of play. If a team scores, says Caputo, the NFL wants to play the sound of fans in that stadium swelling. But it doesn’t want any of the music or sounds of announcers talking.

“Sometimes you would hear a fan yelling out a player’s name who is no longer on the roster. You have to edit that out,” says Caputo. “It was actually a very tedious process.”

The NFL also had to train individual operators on “tool kits” that allow them to manipulate the stadium noises. “There’s a little bit of a learning curve – how to get up to speed firing the reaction in time, and how to work the controls to make things sound as natural as possible,” Caputo says. “We had a few ups and downs in the first week.”

But league executives think the “real” commotion of  fans lends TV broadcasts something distinctive. And besides, the hubbub was easy to find. “I guess we did it because we could,” says Caputo.