Comprehensibility-based Evaluation of Real-time News Subtitling

Abstract

The possibility of real-time subtitling of news programs-using an uncondensed transcription of the words spoken by the newsreader-was considered for people with impaired hearing. Before the system can be created, the effectiveness and preferred format of subtitling need to be investigated. In order to evaluate the comprehensibility of real-time subtitling, subjects with impaired hearing were shown a short news program with subtitles and without sound, and their comprehension of its contents was subsequently tested. Results indicated that the subjects performed about as well after viewing a program with subtitles at the full rate of 280-350 Japanese characters per minute as people with normal hearing did after viewing a program with sound only, and better than after viewing a program with neither subtitles nor sound. Furthermore, they showed no less comprehension than when the subtitles are condensed to 50-70%, as is common broadcasting practice, suggesting that real-time subtitling at full rate is effective for people with impaired hearing.