The actress, who's deaf, is part of a 3-person jury this year that'll vote in the U.S. Dramatic Competition that's underway at the film fest in Park City, UT. However, because she couldn't make out what was happening onscreen for Majors' flick, 'Magazine Dreams,' she and the other 2 jury members walked out of the screening Friday night ... this according to Variety.

The outlet reports that a captioning device had been given to Matlin before the movie started, but it seems it was malfunctioning ... so rather than delay the screening further -- it had already been pushed back 45 minutes -- the jurors collectively walked out in protest.

Apparently, this is part of a larger issue at Sundance ... which came to a head during Majors' movie. Variety says, citing sources, that a letter had been sent to the participating filmmakers this year pertaining to closed captioning -- imploring them to submit cuts of their films that included it so hearing-impaired viewers could enjoy without hiccups like this one.

It read in part, "As a jury our ability to celebrate the work that all of you have put into making these films has been disrupted by the fact that they are not accessible to all three of us."

Variety reports some Sundance filmmakers have been hesitant to include CC -- as they supposedly feel it could make their movies harder to shop, not to mention the added costs and time that would come in including a completely different copy just for the festival.