ELLSWORTH, Maine — Staffers within the Maine Department of Environmental Protection are recommending that a regulatory board take additional time to finish crafting new rules aimed at addressing noise from commercial wind turbines.

The Board of Environmental Protection, which is the rule-making arm of the department, could vote this Thursday on a proposal to reduce — but only slightly — the decibel level that would trigger a noise violation.

But department staff are recommending that the board delay a vote and instead hold another public hearing on the controversial issue on Oct. 20, with a board vote coming in late November or early December. In their recommendation, department staff said the delay would provide additional time to clarify some key, contentious issues.

“This still allows the rule to be submitted to the Legislature for review before the January 2012 deadline,” reads the staff recommendation.

The draft rule pending with the BEP would lower from 45 decibels to 42 decibels the maximum allowable noise from wind farms between 7 p.m. and 7 a.m. as measured from nearby “protected locations,” such as homes or businesses. The rule also lays out a detailed process for collecting sound readings and compiling noise complaints.

Yet neither critics of Maine’s wind power facilities nor supporters of the wind energy industry appear satisfied with the proposed rules.

Mike Mullen, acting director of the DEP’s Bureau of Land and Water Quality, said Tuesday there is significant disagreement over the 42-decibel recommendation and other standards in the proposal.

More than 50 people requested an additional public hearing on the revised rules.

“We had many people request one, so we felt it was best to advise the board” to open the issue back up to public comment, Mullen said.

Noise from commercial wind turbines has emerged as one of the biggest public relations issues for Maine’s rapidly growing wind energy industry.

Maine’s noise law applies a decades-old standard that critics contend did not anticipate the unique noise and vibrations generated by 400-foot-tall wind turbines. Industry representatives argue that the existing standards and practices observed by companies are sufficiently protective of the public health.

Critics of Maine’s wind power industry who gathered enough petition signatures to force the board to begin the rule-making process to address wind turbine noise wanted a 35-decibel limit at night. They have accused the department of ignoring scientific evidence presented during hearings supporting a lower level.

Industry representatives maintain, however, that sites are carefully chosen and designed to minimize impacts on neighbors and that the vast majority of Mainers strongly support expansion of wind energy in the state.

Lynne Williams, a Bar Harbor lawyer heavily involved in the fight for stronger regulation of noise and scenic impacts from wind turbines, said Tuesday evening that department staff and board members have not changed their recommendations in response to feedback at past public hearings. So Williams said she personally doubted a much different outcome even after another public hearing.

The Board of Environmental Protection is slated to discuss the issue during its regular meeting, scheduled for 9 a.m. Thursday at the Augusta Civic Center. Any rules given provisional approval by the board would have to be reviewed by lawmakers.