CLINTONVILLE, Wis. — An eastern Wisconsin town where unexplained booms have kept some residents up at night will hire an engineering firm to explore the cause of the racket, the city’s administrator said Thursday.

The Waukesha engineering firm Ruekert & Mielke will install ground seismology monitors in four places around the town late today or early Friday, Clintonville administrator Lisa Kuss said.

“The purpose is trying to determine some sort of epicenter to the event,” Kuss said. “If you can do that, then you can focus on how deep it is.”

The engineers will set three monitors up in a triangle, with the fourth in the middle, and they will stay in place until they produce a clear reading of seismological activity, Kuss said. She didn’t know how long the tests would take.

The city has authorized $1,000 to rent the machines and up to $6,000 for analysis.

Dozens of residents began reporting the loud booms on Sunday night. Some said it sounded like an explosion, others that is was more like a door being slammed. Some cited fireworks, others wondered if they had experienced an earthquake.

The complaints continued on Monday night and more came just before dawn on Wednesday. Police received a handful of calls early today reporting minor booms, but nothing on the scale of the previous nights.

No injuries have been reported although some residents said they could feel the ground roll beneath their feet.

City officials say they have investigated every possible human cause. They checked water, sewer and gas lines, contacted the military about any exercises in the area, reviewed permits for mining explosives and inspected a dam next to City Hall. They even tested methane levels at the landfill in case the gas was spontaneously exploding.

Some folks said they were considering leaving town until investigators can determine the source.

“My husband thought it was cool, but I don’t think so. This is not a joke,” said Jolene Van Beek, who awoke early Sunday to a loud boom that shook her house. “I don’t know what it is, but I just want it to stop.”

Van Beek took her three sons to her father’s home, 10 minutes away, so they could get some uninterrupted sleep.

About 300 people attended a public meeting Wednesday night in a local high school auditorium to get an update on the situation. Kuss assured residents that officials are doing everything they can to determine the source of the booming.