A public television station has developed a service that makes TV vivid for the blind and visually impaired by having a narrator describe a program's setting and action during pauses in dialogue.

The service, developed by Boston's WGBH-TV, which also pioneered closed captions for the hearing impaired 15 years ago, broadcasts the added narration over a special channel that can be tapped by people with a stereo television or a video cassette recorder.The station tested the service last year and is seeking funding to make it available in January 1990 to the nation's estimated 12 million visually impaired people.

"I never realized when I watched television, from a listening perspective, that I was missing so much," Kim Charlson recalled Tuesday. Blind since the age of 11, the 31-year-old Watertown resident was among thousands of visually impaired people across the country who tuned to the service's trial run.

Television "is a major means of communication in society," Charlson said. "There's so much on television, you tend to feel left out when you can't access it. I really commend them that they're trying to do it, and do it right."

Descriptive Video Services allows anyone with visual impairment - or even sighted people stepping away from their TV set - to follow the show. With a stereo television set or VCR tuned to the Separate Audio Program channel, they can hear a narrator describe a program's scene and action during musical interludes or breaks in dialogue.

WGBH enlisted nine other public TV stations to test the service from January to July 1988 on the PBS "American Playhouse.'