Beginning Sunday, Catholics with hearing disabilities may take part in a new experimental program designed to determine if installation of a special acoustic device around church pews can help hearing-impaired persons participate more fully in services.

The two-month-long trial program will be conducted at St. Jane de Chantel Church in Bethesda under the auspices of the Washington Archdiocese, which hopes to attract persons who have stopped attending mass because they can't hear.

The device, called an audio loop, consists of a coil of wire taped to the floor around seven pews and connected to a speaker and amplifier. According to Desmond Carron, designer of the system, a magnetic field created by the loop will enable persons with hearing aids who sit in the pews to hear "just like they were sitting in front of the speaker."

Carron, a parishioner of the church, at 9701 Old Georgetown Rd., said several area schools and organizations for the deaf have been using loops successfully for years.

Carron, a quality controller with a Rockville technology firm, became involved in audio loop design after he constructed one for his daughter, who suffers from a severe loss of hearing, to use while watching television. Commercial loops are available, he said, but are usually not satisfactry.

Pamphlets describing the loop at St. Jane's will be available at the back of the church, Carron said. In addition, he said, a person familiar with the system will be available at Sunday services to explain aspects of hearing disability and other possible audio loop uses. "People can walk in and sit down in one of those pews without feeling any embarrassment," Carron said.

Carron said that the future of the loop at St. Jane's and other area churches depends on how many people take advantage of it during the experiment. He said he expects only two or three people to try it at each mass during the first two weeks, adding that he doesn't know how many users the archdiocese considers enough to judge the experiment a success.

During the experiment, the church will have several extra hearing aids on hand which it will leand to those persons who do not own one.

Carron said he has already received calls from three other churches requesting audio loops, which cost between $200 and $300. "But I'm not installing them until after I see the results of the experiment at my church."