Wolf Trap's founder and donor, Catherine Filene Shouse, predicted yesterday that revenues this season at the performing arts park will be substantially lower than officials had calculated.

"We're losing money because that center is not holding the same number of people as last summer," said Shouse, referring to Wolf Trap's Meadow Center, a temporary replacement for the Filene Center, which burned down in April. "It holds 2,000 as opposed to 3,500." The Meadow Center, however, accommodates more people on the lawn.

Shouse, who spoke about the financial outlook before testifying at a congressional hearing on Wolf Trap, listed several other reasons why fewer people are turning out for the performances: "We have people who don't come because they like numbered seats--and ours came too late to number. We have people who don't come because they don't have enough room for picnics. It's not the same as last year. You're looking at snow fences. You're much more aware of the tent being readied for the performance. You don't feel as isolated and out of the world as you did when you parked your car and walked up the hill last year."

Shouse said she could not say exactly by how much revenues would fall short. "I can tell you in two to three weeks," she said. "We have a week of 'The Sound of Music' coming up. 'Napoleon' is coming up. Those could affect us."

Carol Harford, president of the Wolf Trap Foundation, said that currently Wolf Trap "is off about 22 percent from projected ticket revenues" of $2.2 million. "But it might even off," she added.

Harford attributed some of the drop in attendance to a change in traditional Wolf Trap fare. "The only opera we can do this year is 'Regina,' " Harford said. In the Filene Center, "we could have done two full weeks of opera." She said discussions on booking dance companies also had foundered because, at the time, Wolf Trap could not guarantee the condition of the new facility's floor.

The major hurdle for Wolf Trap now is obtaining congressional authorization for a $9 million loan needed to begin rebuilding. Wolf Trap officials say if they get the funds by October, they can have the new Filene Center completed by the middle of next August.

At yesterday's hearing, held by Rep. John Seiberling (D-Ohio), who chairs the House Interior subcommittee on public lands and national parks, the testimony centered on acoustics. Fears have grown that if the Filene Center is rebuilt on its original site, it might be subject to more noise interference from a planned Virginia state toll road parallel to the current Dulles Access Road.

Members of the Cinnamon Creek Homes Association, near Wolf Trap, stressed that they supported the rebuilding of Wolf Trap but said the noise on the new road will "significantly deteriorate the performing environment" at Wolf Trap. Armed with maps and graphs, Cinnamon Creek homeowners said the Federal Aviation Administration's planned barriers against the noise were inadequate and asked that the Federal Aviation Administration--which owns and controls the Dulles Access Road--carry out a more detailed environmental study of the noise impact.

The Wolf Trap Foundation, the FAA and the National Park Service all testified that Wolf Trap can be rebuilt on the original site if an appropriate sound barrier is constructed.

However, acoustics experts from Wyle Laboratories who conducted studies on several possible Wolf Trap rebuilding sites for the Park Service found the original site the worst in terms of noise. "All other things being equal, it will be best to put it as far away as possible," said Ben Sharp, manager of Wyle. "But all other things aren't equal."

Acoustics experts from Bolt, Beranek and Newman Inc., who were hired by Wolf Trap and performed tests on Monday, testified that the original site "offers as good a location as the others." They added, however, that the planned sound barrier "is not sufficient to cope with" the noise from eastbound traffic.

Further acoustics studies have been requested, and Seiberling said he hopes to take action on the authorization legislation when Congress returns from recess Sept. 9.