A new 7000-series train arrives to pick up riders at the King Street-Old Town Metro station in Alexandria, Va. (Matt McClain/The Washington Post)

Metro’s sleek new stainless steel rail cars are noticeably different from their clanking aluminum predecessors: They’re shiny, brightly lighted, far more modern.

And for some people, the trains are earthshaking. Literally.

“I can sit at the kitchen table and feel every time a train goes through,” said David Solimini, who lives in the District’s Petworth neighborhood. “It’s obvious. It’s pronounced. It rattles the glass in the cabinet and the pots and pans under the kitchen island.”

Residents say the rumble reverberating through their neighborhood along the Green and Yellow lines began with the introduction of the new 7000-series Kawasaki trains last summer. As more of the trains began to appear, the trembling increased. Proof, residents say, that the new rail cars are the source of the increase in sound and vibration. And some fear it could be inflicting structural damage on ­century-old homes.

The issue was the topic of a December meeting organized by Timothy Jones of the Advisory Neighborhood Commission, where residents complained to Metro officials.

While there has been nothing to officially link the reports of rumbling to the new rail cars, Metro sent its engineers to the neighborhood to conduct “initial field tests” and said preliminary results show “negligible vibration levels.” They have hired outside experts to perform additional tests.

“Because we take this matter very seriously,” Metro spokesman Richard L. Jordan said, “Metro is in the process of bringing in third-party engineers to conduct additional tests before we make a final determination.”

Two days after the neighborhood meeting, D.C. Council member Brandon T. Todd (D-Ward 4) sent a letter to Metro General Manager Paul J. Wiedefeld demanding that the agency get to the bottom of the issue.

“In addition to being a nuisance — waking residents up at 5 a.m. and keeping them awake until midnight or later — this issue endangers residents by threatening the structural integrity of their homes,” Todd wrote.

The new trains are heavier than older models. Their stainless steel frame was designed to be structurally safer and more crashworthy than older aluminum trains, partially as a result of the devastating Fort Totten train crash in 2009. Metro did not respond to requests for data on the exact weight of the new trains.

On a recent Thursday morning, a Washington Post reporter spent two hours in the Georgia Avenue-Petworth station, noting each time that a 7000-series train entered the station. At the same time, Solimini wrote down every time that he heard the loud rumble on the first floor of his house, five blocks away.

The numbers matched perfectly: Every time he noted a significant rumble, a 7000-series train had passed through the station moments before or after.

The test neither definitively proves nor disproves residents’ belief about the new trains. But inside Solimini’s home, this reporter found that the feel of the rumble, rather than the sound, was most pronounced — kind of low thunder in the chest cavity.

Solimini said he used to hear the older trains passing, but only if he was standing on the concrete floor in his basement, and it was more of a buzzing sound. Now, he said, the sound is much more resonant, and he can hear it throughout his house.

At first, Solimini wondered whether he was imagining that the rumblings were growing louder. He checked with his wife; she heard it, too. Then, he came home one day and saw the flier left on his door announcing the neighborhood meeting for residents to air their complaints.

“It was like, ‘I’m not the only one! I’m not crazy!’ ” Solimini recalled.

Solimini, who attended that meeting, said that his concerns don’t quite rise to the level of those of his neighbors. He doubts that the vibrations would have a significant structural effect on his house, and he finds the frequent rumbling “less disruptive and more just distracting,” he said.

Still, he wants definitive answers from Metro.

“I’m not convinced that my house is going to fall into a sinkhole any day,” Solimini said. “But I think people here want an acknowledgment from Metro that, yes, something has definitely changed, and an honest evaluation on the question of whether that change is likely to cause problems for people’s homes.”

Todd said he has not yet received an update from Metro on how quickly they intend to deliver answers about the cause of the rumble. And he pointed out that there are other factors that could potentially be the culprit of the vibrations — particularly the ­extensive track maintenance work that Metro started performing last June.

“Anytime something like vibrations begin when they did not occur before — especially so recently, with the work that Metro is doing with SafeTrack — it’s something that I take seriously,” Todd said. “I just want to get to the bottom of it.”

If officials determine that the rumbles are caused by the new trains, it will be the latest in side effects with the 7000-series trains.

The heavier trains, which run only in eight-car configurations, put more wear-and-tear on the track system — one reason that the Federal Transit Administration has warned that the new trains will necessitate a more frequent track maintenance schedule in the future. The trains also draw more electricity from Metro’s power system, requiring long-term infrastructure upgrades.

And even for Metro passengers who don’t hear the train traffic in their homes, the new trains have created a noticeable change in their daily auditory experience.

Henriette Rahusen, 62, rides the Red Line daily from her home in Bethesda to the Judiciary Square station. About half a year ago, she noticed that she began hearing a new kind of sound while waiting on the station platform for trains to arrive. A train would approach from a distance — its headlights just barely visible at the end of the tunnel — and she would begin hearing a deep, intense reverberation.

“I thought, ‘Ooh, that sounds pretty heavy,’ ” Rahusen said. The sound always preceded the arrival of a 7000-series train. “A train comes into the station, and the rumble of the new trains is just lower. It makes the environment vibrate a little.”

The new noise doesn’t bother her, Rahusen said. But it always makes her look up.

“It’s like the difference between a bass singer and a baritone,” she added. “Both sing low, but one sings lower than the other.”