For travelers who need one more 90-decibel TSA reminder that unattended bags may be confiscated and destroyed, Denver International Airport won’t disappoint.
But DIA officials just implemented a mandatory Quiet Airport Policy targeting the noises they can control — a push to contain the often-overwhelming cacophony of modern air travel and give people peace and tranquility.
They have reprogrammed 200 microphone stations in concourses, installed noise sensors in loudspeakers, and instructed airlines to find alternatives to concourse-wide broadcasts, such as smartphone text messages and digital signs. Public address announcements that must be made “should be kept as brief and clear as possible.” Airlines are encouraged to text or call passengers privately when left-behind items are located, and a “final boarding call” at DIA is taken to be final.
Noise reduction is part of creating “a calmer and more peaceful” airport, not quite a library but a place where brain-addling aspects are replaced with “ambiance,” DIA chief executive Phil Washington said. “We are creating a destination for people.”
A growing body of medical evidence establishes the role of loud noise in triggering physical and psychological distress, similar to light pollution, which can intensify travel anxiety. DIA officials say they see overwhelmed travelers break down or become irritable due to stress. There are no legally enforceable decibel limits for noise inside airports, despite the 52-year-old Noise Control Act that identified rising noise as a major public health hazard.
Denver launched its quiet airport campaign in July, building on efforts in San Francisco and airports abroad in Amsterdam and Singapore, following years of high-decibel construction for a $2.1 billion expansion of DIA to be able to handle 120 million travelers a year. DIA has emerged as one of the world’s biggest and busiest air travel hubs with nonstop flights reaching as far as Istanbul, Rome, and Tokyo.
The effort to reduce airport noise “is very commendable,” said health scientist Jamie Banks, president of Quiet Communities, a national nonprofit that fights harmful noise and promotes quietness as a valuable natural resource.
“When you move from a noisy to a quiet environment,” Banks said, “you can almost feel the stress melting away.”
Ambiance overhaul
First, airport maintenance crews reset the 200 microphone stations in DIA’s three concourses. Airline agents wielding microphones previously could make announcements reaching up to 70 gates at once. The modified mics reach just one gate and the immediately adjacent area.
Then, the crews installed sensors on loudspeakers to measure overall ambient noise. DIA hired an audio control contractor to record announcements. A mapping system allows analysis of frequency and duration gate by gate.
Over the next two years, DIA customer experience and operations crews plan to hunt for problematic noises — roaring heating, ventilation and air-conditioning systems (HVAC), beeping carts carrying travelers who can’t walk, rattling escalators, squeaky moving sidewalks, shops and restaurants that project “yacht music” into concourses, and bathroom hand dryers that exceed the decibel levels of a gas-powered leaf blower.
“We want to address, as best as we can, all of the little noises,” said Kyle Lester, DIA’s senior vice president for maintenance.
But eliminating any source is a challenge, Lester said. For example, sustainability advocates favor those hand dryers to reduce the use of paper towels.
Once they’ve delivered tranquility, DIA officials plan to carefully incorporate music. Washington suggested jazz. Experimental concerts last summer on DIA’s 82,000 square-foot open-air south plaza, looking out toward Pikes Peak, proved popular. DIA officials also plan to address light pollution, though ground crews have raised concerns. Ultimately, travelers may be able to glimpse stars the way they do in Wyoming at the Jackson Hole Airport.
“With our space out here, 53 square miles,” Washington said, “we can probably see more stars than at any other airport in the world.”
Some noise must stay
However, some of the loudest noises must stay, such as the pre-recorded Transportation Security Administration warnings about unattended bags. TSA requires that DIA operators play these at least once every 30 minutes. Denver’s fire code requires broadcasting all emergency, safety, and security announcements at volumes at least 15 decibels louder than the ambient sound. That means noise approaching 100 decibels, loud enough to cause ear damage.
The noise order issued Aug. 1 said public address systems may be used “only when absolutely necessary.” In the future, airlines should rely on “signage” or digital displays, instead of public address systems, for routine reminders. Background music, permissible in DIA’s terminal, shops, eating areas, and certain “quiet zones,” must be contained within those areas.
Compliance with the policy is mandatory, DIA’s policy document says, warning that airlines and others producing noise “will be monitored” by DIA “life safety” officials. Maximum penalties for violators have not been set.
United Airlines accepts the new rules, company spokesman Russell Carlton said. United has found that reducing its announcements brought “no real impacts,” Carlton said, noting 20 million United customers have downloaded the company app and that 84% use it when they fly.
“We’re still permitted to make boarding area announcements for our customers. We’ve already thoughtfully reduced the amount of gate area announcements we make, and coupled with real-time updates in the United app, we’re able to keep our customers informed,” he said.
In cases where travelers leave a laptop on a plane, Carlton said, “instead of making an airport-wide announcement for that passenger, we’ll call them on their phone instead.”
Southwest Airlines gate agents, slated to abandon their announcement-heavy open seating boarding process in January, have also signed off. “Southwest is supportive of the program and is participating in the rollout at Concourse C,” company spokeswoman Laura Swift said.
At DIA, “all airlines are on board,” DIA spokeswoman Keylen Villagrana said.
Air travel became ‘an extra stressful event’
Noise levels have become a concern at airports nationwide over the past decade, in part due to the development of airports as “destinations” for shopping, dining, and hanging out in addition to the primary purpose of air transportation. As noise levels increased, airport officials received complaints and increasingly observed instances of travel anxiety and stress overwhelming travelers, including adults and children who struggle when stuck in busy areas buffeted by too much information, bright light, and loud noise.
“We see it all the time. They come into the airport, and it is an extra stressful event for them. They hear announcements, and it just makes them confused. They stop. They say: ‘I don’t know where to go,’ ” said David Matos, DIA’s director of maintenance administration and an architect of the noise reduction campaign. “Between all the signage and the way-finding and the noise, a lot of folks get stressed out. They act out at the ticket counters. They push on the trains.”
San Francisco International Airport officials pioneered noise reduction, taking advantage of a pandemic lull. Airport director Mike Nakornkhet, who has worked at DIA, helped lead efforts that officials say has reduced unnecessary noise by 40% and eliminated 90 minutes of announcements per day. The changes in San Francisco included the prohibition of boarding announcements in the pre-security parts of the airport.
“We hope that travelers will find something that was previously harder to come by in our terminals: a little peace and quiet,” Nakornkhet said in a public letter.
Chasing calmness
At DIA, reducing noise is part of a broader transformation. Travelers increasingly want to be able to work, and DIA officials say they’re prioritizing the installation of more work tables and charging ports — creating spaces that can be calm and peaceful.
“It is hard to engage in a work call or a work meeting when you have high background noise,” Lester said. “We want to create that environment of calmness. High noise induces stress and fatigue. We want to create a customer experience of peace, especially during long waits and layovers. Flying is stressful enough. For our customers, more noise just adds to that stressful environment, especially for our neurodivergent customers.”
Last week, travelers reeling from uncertainty as the federal government shutdown ended acknowledged multiple stressors complicating their trips.
Standing by an elevator with his phone to his ear, trying to hear where to meet his ride, Bill Richey, who had just flown from Ohio, plugged a finger into his other ear as an overhead public address announcement boomed down. Overlapping announcements around airport gates are the worst, Richey said. “It stresses you out. It makes you think you’re going to miss something.”
Metro Denver resident Bob Brewster said he would avoid air travel if possible. “I’d rather take the train.” But the cost of Amtrak options from Colorado typically is too high compared with flying.
DIA announcements at concourses are loud, but the airport has the advantage of carpeting that absorbs noise — superior to other airports such as the one near Philadelphia, Brewster said.
Part of the appeal of travel is hearing a symphony of sounds, some of them pleasant, said Missy Gotelli, who arrived from Sacramento this week and had no complaints as she sat in a baggage claim area where a National Institute for Occupational Safety and Health phone app noise meter measured 89 decibels, the equivalent of power tools. “It’s an airport. Suck it up,” Gotelli said.
Yet she saw room for improvement. “What I do enjoy is live music,” she said.
“Jazz would be nice.”
The design of DIA’s signature tented terminal “is an acoustic nightmare,” and DIA officials will have to overcome that to reduce ambient noise to a comfortable level, said Colleen Cussick, looking up at the roof. She used to work in the recording industry. Any noise in the terminal “is going to reverberate,” Cussick said.
“But compared with other airports, this is incredibly quiet,” she said by the Caribou Coffee cafe on the sixth level.
The overall soundscape at DIA is improving, she said, and the airport is appealing enough that she recently came here simply to meet with a friend during a layover for a meal, assuming they could find decent food, she said.
“It seems to be a little more chill.”
Get more Colorado news by signing up for our Mile High Roundup email newsletter.