This research proposal aims to investigate the effect of using English documentary videos with English subtitles on students' listening comprehension abilities. The researcher plans to conduct an experiment comparing students' listening test scores after watching documentaries with and without subtitles. Previous studies have found that subtitles can help learners understand content while also improving listening and reading skills simultaneously. However, subtitles in students' native language may distract from developing English listening skills. The researcher intends to determine if English subtitles specifically can boost listening comprehension for diploma students in Malaysia compared to no subtitles. The proposal outlines the research questions, objectives, methodology, and significance of addressing this gap in knowledge about optimal listening instruction tools.