BANGOR — Punctuated by the pounding of a jackhammer, a half-hour visit Wednesday to the old part of the Freese’s building revealed little more than busy workers threading their way through dimly lit piles of lumber.

But something amazing is taking shape in the minds of Jeanne Finan and Reb Haizlip.

The Eastern Maine Children’s Museum is set to open in December 2000 on three floors of the Main Street landmark.

The exhibit designers can already hear the laughter of children exploring Maine nature trails, manipulating robot arms on Mars, and checking out that really big brain in “The Body Journey.”

Finan, an exhibit developer from Valle Cruces, N.C., and Haizlip, a designer from Memphis, Tenn., were in Bangor to check out the future museum space and meet organizers of the capital campaign that already are working on raising $3.75 million for the project.

The two have been involved with children’s museums all over the country, beginning with the Children’s Museum of Memphis in 1989. They bring a variety of experiences to their work.

A former director of children’s museums and well-known speaker on museums and children, Finan is also a musician who was once the opening act for singer James Taylor. Haizlip has done design work in London.

Finan will “refine and pare” ideas for the exhibits, a job that involves a lot of research, Haizlip said. He, on the other hand, will tackle the physical, technical aspects such as deciding how big the components will be, where they will fit, and how they will operate.

“I’m the hands, and Jeanne is the brains,” Haizlip said, a description Finan said she would be glad to pass on to her children.

Locally, the Bucksport architectural firm Lewis & Malm will work with the designers to make sure there is a good fit between the available space and the end result.

The company has done three child care centers, more than 35 schools, and other public spaces such as Ellsworth City Hall, said Rick Malm.

It’s not enough to simply juxtapose one exhibit with another, Malm pointed out. “There needs to be a certain flow through the building.”

“We’ve already done several schematic concepts,” he said. The final design of the exhibits should be ready later this year, with fabrication beginning in early 2000. The exhibits would be installed over the summer in order to be ready for the December opening.

Approximately a third of the museum’s 24,000 square feet will be devoted to exhibits. Other space will house a small theater, museum offices, a lobby and gift shop.

In addition to several permanent exhibits, there will be a revolving exhibit space to host traveling exhibits from other museums, as well as displays created by Maine high schools and colleges.

Fund raising is continuing, said campaign committee chairman Susan Carlisle, a member of the Bangor school committee.

Carlisle wasn’t ready to talk about the amount raised so far, but said the committee was working with a variety of people and businesses, not to mention applying to foundations for grants. “We’re well on our way,” she said.

“We’re very grateful to the city of Bangor,” said Sean Faircloth, director of Partnerships for Healthly Communities, which led the grass-roots effort to get the museum on its way.

The city, in fact, is borrowing $1.9 million to help renovate the building — $1.25 million of that amount for the children’s museum space. Remaining space on the first three floors may house an arts center, and the city has been in discussions with two applicants — the University of Maine and Portland’s Maine College of Art.

On the top three floors, Realty Resources Chartered of Rockport will develop assisted living apartments for the elderly, a companion project to the senior citizen housing operating in the rear part of the building. Pen Bay Builders of Rockport is doing the construction for the building.

For information on the capital campaign for the Eastern Maine Children’s Museum, contact Martha Dudman, campaign manager, at 941-0942.