MINNEAPOLIS -- Military veterans reported fewer flashbacks and nightmares related to PTSD after spending a 60-minute session in a Minneapolis research lab dubbed “the quietest place on Earth.”

The results, reported recently by researchers at the Minneapolis Veterans Medical Center, suggest that doctors could offer sight and sound deprivation as supportive therapy for post-traumatic stress disorder. The small startup study was so successful in providing at least short-term relief that researchers are looking to solidify their findings by recruiting more veterans to sit in the soundless chamber.

“The feedback we’re getting from veterans, almost 100% of the time, is that it was really relaxing,” said Casey Gilmore, a study co-leader. “They really liked their time in the chamber. Most of them want to do more.”

PTSD is a condition by which people routinely relive the disruptive levels of fear and anxiety that they suffered after traumatic events. The condition is common among military members after they return from wartime deployments, but has been found in as many 1 in 20 U.S. adults as well.

VA researchers tested their theories about how to calm PTSD at the anechoic chamber operated by Minneapolis-based Orfield Laboratories — a steel-walled room suspended by vibration-damping springs and lined with fiberglass wedges that absorb 99.99% of sounds.

Twenty veterans each spent 60 minutes in the darkened chamber, which as recently as 2021 was declared by Guinness World Records as the quietest place on Earth. The veterans also spent time for comparison listening to “pink noise,” which Gilmore likened to sitting in a quiet bedroom at home with the air conditioner running.

The veterans used mobile devices to describe their emotional states four times each day, both in the two weeks before their sessions and in the two weeks afterward. Intrusive thoughts and negative moods declined significantly after their sessions in the ultra-quiet chamber, results showed.

The discovery was one of dozens highlighted this month at the annual research day at the Minneapolis VA. Other studies probed the origins of Alzheimer’s disease, the connections between toxic wartime exposures and respiratory problems back home, and the best ways to support veterans with disabled or missing limbs.

PTSD has long been a focus area for the Minneapolis VA, where surveys found symptoms in almost 1 in 5 Minnesota National Guard members after they returned in 2007 from deployment in Iraq and resumed civilian lives.

Studies since that time have examined the therapeutic benefits of everything from meditation to exposure therapies to role-playing games such as Dungeons and Dragons.

A studio used by Prince

Imaging studies by other researchers suggest that people with PTSD are overstimulated by sights, sounds and other senses in a way that overwhelms their brains. In this new study, Gilmore and his team are trying to give the nervous system a break so it tamps down the sensory signals it sends to the brain. (The study goes by the acronym RESET, short for reduced external sensory environment therapy.)

The anechoic chamber was added to the former site of Sound 80, a recording studio for musicians, including Prince and Bob Dylan, for corporate and design research. People wanting to experience sensory deprivation can rent it as well.

Owner Steve Orfield has conducted design research on the ideal conditions and facilities for people with dementia and autism. He said he encouraged the VA study and was eager to donate time in the soundless chamber to find solutions for veterans and military members struggling with PTSD who are at elevated risk for suicide after deployments.

Other studies have used flotation pools to show that sensory deprivation can yield anxiety-reducing benefits, but Gilmore said this is one of the first to use an anechoic chamber and recruit veterans. The initial study only tracked veterans for two weeks after their sessions in the chamber, so it is unclear if the benefits last longer than that. Follow-up studies will determine if even one ultra-quiet session can produce longer-lasting relief, he added.

Even if follow-up studies are favorable, Gilmore said the endgame probably won’t be the construction of more of these costly, sophisticated chambers. It’s possible that therapeutic benefits occur in dark, quiet conditions but don’t require total silence.

“It’s kind of like a drug-dose kind of study,” he said. “Maybe this is like the highest dose we can give people, but most people won’t need this high of a dose for it to work for them.”

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