Tonight the Kennedy Center will begin offering theatergoers a new service: a sound amplification system for the hearing-impaired.

Thirty wireless headsets and hearingaid attachments will be available in the center's Eisenhower Theater for the performance of "Whose Life Is It, Anyway?" The sets will pick up and amplify an infrared light signal from four emitters -- approximately 6-by-7 inches square -- attached to poles onstage.

The system, paid for with a $20,000 grant from Public Welfare Foundation, a washington-based private charity, will permit hearing-impaired members of the audience to hear from any seat in the house. Other systems, in which amplified sound is carried through wires, oblige the hearing-impaired to use only specific seats equipped with headsets.

The equipment will be available in the lobby of the theater on a first-come, first-served basis. There will be no advance reservations.

According to Richard Owens, associate manager of the Kennedy Center theaters, the center has been experimenting with various sound amplification systems since it opened in 1971. But after tests with members of the Washington Area Group for the Hard of Hearing, center officials felt the new system was the first one technologically advanced enough to be worth permanent installation.

"I would hope this will open up the avenue of theater to people who may not now be able to come," said Owens. He added that the center will soon order another 30 listening devices, and may also install the system in the Kennedy Center's other theaters.