By Amy Qin

New York Times

BEIJING >> Audience members using cellphones bedevil performers and presenters around the world. But in China, theaters and other venues have adopted what they say is an effective — others might say disturbing — solution.

Zap them with a laser beam.

The approach varies, but the idea is the same. During a performance, ushers equipped with laser pointers are stationed above, or on the perimeter of, the audience. When they spot a lighted mobile phone, instead of dashing over to the offender, they pounce with a pointer (usually red or green), aiming it at the glowing screen until the user desists.

Call it laser shaming.

“It’s usually only a small fraction of the audience that we have to deal with,” said Wang Chen, an employee in the theater affairs department at the Shanghai Grand Theater. “They can’t help themselves. So we try to give them a gentle reminder, so they know what they’re doing.”

Xu Chun, 27, who was in the audience for “Carmen” at the National Center for the Performing Arts in Beijing last month, said: “Of course it’s distracting. But seeing lighted-up screens is even more distracting.”

For the uninitiated, the appearance of a blazing colored beam in a darkened theater can be jarring.

“I remember the first time I saw the lasers, it was shocking to see that little red dot in the middle of a performance,” said Joanna C. Lee, a consultant for American symphony orchestras touring China. “Like someone was pointing a gun at the audience.”

Indeed, the narrow shaft of bright light can connote danger. Laser sights are a popular feature on firearms, and there have been numerous incidents in which lasers aimed at cockpits have impaired pilots’ ability to fly safely. (There are more benign uses for a laser pointer, of course, like making presentations and playing with cats.)

But laser pointers have been used for years as disciplinary devices at many of China’s leading performance halls, including the National Center, the Shanghai Oriental Art Center and the Shanghai Grand Theater.

The key, said Yang Hongjie, deputy director of the theater affairs department at the National Center, is to make ample use of the pointers early in a performance so that offenders (as well as nearby patrons) know what to expect should they dare to sneak a photo.

It helps matters that many big-name venues employ cellphone-jamming technology, so texting and ringtones are rarely problems. (The use of such technology is illegal in the United States, except by authorized federal law enforcement.)

“In the beginning, it was really bad,” Yang said of the National Center, which opened in 2007. “People would talk on the phone and take photos all the time during performances.”

But he and his colleagues found that sending ushers individually to stop patrons was not only distracting for other spectators but also a problem if the offender was sitting in the middle of a row. So in 2008, the center began training ushers to use lasers.

“It’s gotten better and better over the years,” he said. “We have much less interaction with the audience now, compared to before.”

In the United States, the use of laser pointers is highly regulated. In China, although performing arts associations have issued guidelines, the devices are largely unregulated. It is not uncommon, while walking in Sanlitun, the popular shopping and night-life district in Beijing, to be temporarily blinded by a flash of green light from one of the laser pointers for sale by sidewalk peddlers.

“It’s really only a risk if they hit the eye,” Samuel M. Goldwasser, a laser expert and former professor of electrical engineering at the University of Pennsylvania, said in a telephone interview.

That is why, Yang said, ushers are specifically trained to aim at patrons from behind, in order to avoid the eyes.

There have also been complaints when the lasers are used too much during a performance, as at a concert in Beijing in January featuring the celebrated Chinese pianist Lang Lang. There were so many people trying to sneak a photo of him that at times it seemed as if a laser show had been organized to accompany Lang’s tender rendition of Tchaikovsky’s “The Seasons.”

As a result, some troupes, like the Royal Shakespeare Company during its China tour last month, have asked performance halls to refrain from using the devices during their appearances.

Yet theater managers here say the lasers are the best solution they have found to a nagging problem. Many say such “uncivilized behavior” will stop only when people improve their suzhi, a Chinese term meaning quality or refinement.

“Hopefully, one day we won’t even need to take the laser pointers out of our pockets,” said Wang of the Shanghai Grand Theater. “That would be a good day.”

© 2016 The New York Times Company