Deferred multimodal input enhances L2 listening and fast-speech adaptation: A predictive coding perspective

For learners who find reading easier than listening and struggle to keep up with the speed of native speakers, listening practice that emphasizes linking sounds to written words and adapting to speech rate is essential. This study investigates the effects of deferred multimodal presentation, an input method that temporally separates reading and listening. Unlike simultaneous input (e.g., reading-while-listening), this sequential approach reduces cognitive load by preventing split attention and facilitates auditory decoding by leveraging prior information from another modality. Ninety-nine Japanese EFL learners, including a control group, engaged in five days of structured practice under one of four conditions: (1) normal-rate audio only, (2) fast-rate audio only, (3) transcript reading followed by normal-rate audio, or (4) transcript reading followed by fast-rate audio. Posttest results after the five-day practice sessions showed that transcript-supported listening—particularly when followed by fast-rate audio—led to greater improvements in both listening proficiency and adaptation to fast speech compared to audio-only conditions. These findings suggest that deferred multimodal input enhances predictive coding—the brain's mechanism for inferring incoming information based on prior knowledge—and supports the consolidation of meaning retrieval. Through such practice, learners can form sound–meaning integrated representations, ultimately improving their listening proficiency.