ELK GROVE, California — High above the city of Elk Grove, a helicopter made four different passes in a matter of minutes around 1 p.m this afternoon.
It was all part of a noise test to see just how loud a helicopter would be for emergency medical flights over the surrounding neighborhood.
To capture and record the sound, ten sensors were placed around town, including at the Stone Lakes National Wildlife Refuge, where a microphone was placed about 15 feet high in a tree.
"It's not required that they test for the helicopter. But, we wanted to know how loud it was going to be as it approaches and lands on the future 12th story of the hospital," said Brian Holloway, spokesman for California Northstate University, which is not affiliated with the UC or CSU school system.
Peter Mbonu, who has a home close to where the proposed 12-story teaching hospital and trauma center would be built, came out to watch the chopper test, and has no problem with the university expansion.
"Yeah, they need a trauma hospital around. People don't have to drive to what do you call it? South Sac," said Mbonu.
The $900 million project is still going through the approval process with an environmental impact report.
About two-thirds of the nearby Stone Lake Shopping Center would be leveled to make way for the hospital addition.
Neighbors like Uva Wallin are concerned about increased traffic.
"I mean the facility would be great for people, but I think it's going to be just a traffic hazard up there," said Wallin.
The proposal for the 25-acre project was submitted to the City of Elk Grove nearly a year ago.
If approved, it could be completed between 2022 and 2025.
FREE ABC10 APP:
►Stay In the Know! Sign up now for ABC10's Daily Blend Newsletter
WATCH ALSO: