CHICAGO — Teens shuffle into the classroom, backpacks slung over shoulders and earbuds dangling. Jokes among friends fly as the students plop into desks arranged neatly in rows.

The instructor in the green shirt jingles a small silver bell. The room grows still. Murmurs fade.

The polished wooden floorboards creak amid the pressure of shuffling feet. A portable fan whirs. Then the room turns quiet.

For the next 20 minutes, there is no lesson, no talking, no laughing, none of the bustling sounds of a high school classroom on a weekday morning.

The boys and girls close their eyes and allow their bodies to relax. Some rest their heads on the palms of their hands. Most close their eyes.

These Gage Park High School students are participating in Quiet Time, a transcendental meditation program that aims to help them with the stress and pressures of life inside and outside the brick walls of the Southwest Side school.

This happens twice a day. Every school day.

The program is run by the David Lynch Foundation, a nonprofit organization co-founded by the movie director, and is being studied for its effectiveness by the University of Chicago Crime Lab. Researchers are examining whether the meditation program offers tangible benefits for teens at a school where 98.3 percent of students are considered low income.

“In their neighborhood, they are fighting to survive, literally,” said Jose Morales, who teaches English as a second language. “And they need an alternative to the violence.”

Quiet Time was one of three programs, out of 200 applications, selected by the Crime Lab when it asked for proposals to help address youth violence in the city. The Crime Lab awarded a $300,000 grant to the foundation to launch the program in Chicago Public Schools because of its goal to address the effects of toxic stress on young people. Quiet Time also has been implemented in San Francisco, Los Angeles and New York City. The Crime Lab believed the program showed promise because of its demonstrated success in the other cities, executive director Roseanna Ander said, and it was helpful that it was cost-effective to launch and had the ability to be rigorously evaluated.

“It helps you to slow your mind. It helps you to slow down and focus,” said James, 17, a senior at Gage Park. The school requested students' last names not be published.

Before taking part in the Quiet Time program, James said he was quick to anger and often was arguing and fighting. Now, James said, he is calmer and thinks about how to react when someone says something objectionable or he finds himself in a stressful interaction.

“I feel it can help people in school and out of school and with everything you do in life,” James said after a restful meditation session.

Initially, James said he thought the program was going to be an opportunity to nap, but after learning how it worked, he gave it a try and was surprised at what he found. James has even had friends who do not attend Gage Park ask him about meditation, and he's trumpeted its benefits.

Quiet Time also has been rolled out at Daniel Hale Williams Preparatory School and Bowen High School. In order to study its effects, students at the beginning of the school year were randomly selected for the program, while others participate in a general quiet period that serves as a control group. At Gage Park, the entire school goes quiet at the same time twice daily, even though only about half the students are meditating.

Staffers with the foundation teach the students the basics of transcendental meditation, learning how to focus on a phrase or mantra that allows them to rest their minds.

Bob Roth, chief executive officer of the foundation, said transcendental meditation is a state of “restful alertness.” It helps kids relax and aids in learning readiness, he said.