The promoter of an outdoor concert in Westbrook on Sunday night voluntarily lowered the volume after about 130 complaint calls were logged.

The promoter has fielded hundreds of complaints about the noise from musical performances at the Rock Row development site since the first concert at the new outdoor amphitheater on May 26. Sunday’s concert by guitarist Joe Bonamassa drew about 130 calls, said Lynda Adams, a consultant to the developer of the site, which will eventually include restaurants and shops, offices and apartments.

Some concerts in May and June drew more than 200 complaints, but Sunday was the first time the volume was adjusted during a  concert.

Adams said a compliance officer hired by the promoter, Waterfront Concerts, made the decision to cut back on the volume of some speakers mounted over the stage sometime before 9 p.m. Sunday. Adams did not say how much the volume was reduced. At least one Portland resident who complained about the sound said she didn’t notice any change in volume.

Under the rules agreed to by Waterfront Concerts and Westbrook, sound levels at meters located around the city have to be below 55 decibels – about as noisy as an office conversation – or 5 decibels above background noise, averaged over an hour, whichever is higher. The noise hasn’t exceeded those levels at earlier concerts, Waterfront Concerts said, and Adams said the noise from the concert Sunday stayed below those levels, as well. But, she said, the volume on speakers above the stage was reduced because of where the complaint calls were coming from.

Many of the complaints Sunday night came from the Nason’s Corner area in Portland, she said, where previous concerts also have drawn complaints. The neighborhood off Brighton Avenue in Portland is about two miles from the concert site.

Maya Lena, president of the Nason’s Corner Neighborhood Association, said she was one of the callers Sunday to the complaint line set up by Waterfront Concerts.

“It’s kind of ridiculous how loud it’s been,” Lena said. A representative of Waterfront Concerts met with the neighborhood association last fall and assured residents noise would not be a problem, she said. Instead, “it’s been an issue throughout the summer,” she said.

“It’s definitely affecting Portland communities,” Lena said, but members of her association are worried that people will get frustrated and stop calling the complaint line if there are no changes and that officials will incorrectly assume the problems have been addressed.

“There’s a little bit of fear among the neighbors that people will stop complaining and just accept this as the new normal,” she said.

Barbara Behn, who lives off outer Forest Avenue in Portland, said she also called to complain Sunday night. She also didn’t notice any difference in the noise level from the beginning of the concert at about 7:30 p.m. until it ended at 9:45 p.m., after Adams said the volume had been cut.

Her windows were open and the noise made it difficult for her to watch a movie on TV, Behn said. “Why should a business in Westbrook hold people in Portland hostage?” she said.

There was a monthlong lapse in concerts before Sunday’s performance by Bonamassa, a blues rock guitarist. The upcoming  schedule for August is the heaviest of the season. There are two concerts this weekend, another two on Aug. 10-11, and then two on the last weekend of the month before the final concert of the season in September.

“Alice Cooper is coming up and I’m not looking forward to it,” Behn said, referring to the Aug. 10 concert by the hard rock act.

Adams said Waterfront Concerts has been tweaking the volume settings and speaker locations in an effort to reduce the complaints. However, concert officials have said their efforts are sometimes stymied if performers bring their own sound equipment.

City officials have said the evidence they’ve seen suggests Waterfront Concerts has been abiding by limits the city imposed. If officials determine that the noise is an ongoing problem, they could cut the number of concerts approved for next year.

Setting up the complaint line and having a compliance officer at the concerts are among the conditions city officials established. Waterfront Concerts provides a report after each concert, detailing noise readings, concert starting and stopping times and other data.

At one point in June, Westbrook police asked residents to stop calling them with complaints, because they have no control over the noise and the calls threatened to tie up emergency response services.