Caption Occlusion

The phenomenon where captions or subtitles visually block or cover other important information displayed on a video screen. Caption occlusion is a significant accessibility concern for Deaf and Hard of Hearing viewers, who depend on captions for dialogue access but may simultaneously need to see onscreen visual elements such as speakers' faces, news tickers, graphics, and text overlays. Research has shown that caption occlusion leads to viewer dissatisfaction and reduced comprehension, and that the severity depends on which information region is blocked and when during the video the occlusion occurs.