With their houses trembling for more than a year, homeowners who live near a Metro tunnel are increasingly puzzled by Metro's latest explanation for round-the-clock rumbling.

Neighbors in the Petworth neighborhood of Northwest D.C. maintain the shaking appeared along with the rollout of Metro's new, 7000 series trains.

RELATED: Metro cars still shaking D.C. homes

"It's only a few seconds and then it's gone," neighbor Hannah Martin told WUSA9. Her home, more than a mile away from the Georgia Avenue-Petworth Metro station, shakes dozens of times a day.

After a series of reports by WUSA9, Martin's home was one of ten sites picked as part of a geological study commissioned by Metro. Engineering firm Wilson-Ihrig, a third-party contractor, ran the tests. The results were recently made public.

While the 400-page report says that 7000 Series cars are heavier, louder, and cause more vibration than their predecessors, WUSA9 found that Metro leadership denounces the theory that new cars have been causing the new tremors.

"I think that could be part of it," Metro General Manager Paul Wiedefeld told Transportation Reporter Pete Muntean.

RELATED: Feds now investigating if Metro trains shake homes

Metro stresses findings in the Wilson-Ihrig report that say vibrations are not great enough to cause structural damage to homes. "The outside vendor we had said it was below the standards," said Wiedefeld.

Homeowners like Martin are frustrated by the answer and think they have no recourse.

"It seems like there's more investigating they could do to see if it's certain cars or if there's any way to lessen it," said Martin. "It seems like they haven't gone as far as they could in trying to figure that out."

District City Councilman Brandon Todd, who represents Petworth, said he has exhausted every option with Metro. WUSA9 went to Ward 2 Councilman and Metro Board Chair Jack Evans, who promised to stay on top of the agency about the problem underground.

"I want to say to the residents please don't give up and don't feel like your voice isn't being heard because it is," said Evans.

Wmata GR Noise Vibration Final by WUSA9 TV on Scribd