Audiovisual Input and L2 Pronunciation Development: A Review of Caption Design, Attention, and Exposure Conditions

Abstract

This review analyzes research on how audiovisual input supports second language pronunciation development by examining perceptual mechanisms, caption design, and exposure conditions. Studies on multi-modal alignment show that captions can guide attention to phonetic cues when they are selectively displayed or temporally synchronized with the speech signal. However, in the condition of full captions and form-focused tasks often cause excessive cognitive load. Research on caption types demonstrates that partial captions, keyword captions, and audio-synchronized highlighting promote more efficient decoding than dense or static text. Although proficiency consistently predicts learning outcomes more strongly than caption mode, long-term evidence indicates that extensive viewing still has benefit on lexical consolidation, listening confidence, and gradual reduction of caption dependence. Overall, audiovisual input is most effective when textual support is minimal, well-timed, and embedded within sustained and increasingly authentic listening. The review identifies the need for longitudinal and dose–response designs to clarify how input amount shapes measurable phonetic gains.