VietTESOL International Convention 2026

This study investigates the effectiveness of Electronic Visual Feedback (EVF) using Praat software in improving English intonation among English-major students at a public university in central Viet Nam. Ten English-major students participated voluntarily in a three-week pre-experimental intervention involving a pre-test and a post-test. During the intervention, participants compared and adjusted their pitch contours against native-speaker models. Common intonation deviations were first identified from the pre-test recordings. Subsequently, four independent raters, including two native speakers and two university lecturers, evaluated these deviations using an assessment rubric to categorize them according to their impact on semantic meaning. Finally, post-test recordings were compared with pre-test data using a Paired-Samples T-Test to evaluate the effectiveness of the Praat-assisted intonation training. Analysis of the pre-test recordings revealed five primary intonation deviations: overcomplicated pitch movements, simplified intonation contours, reversed pitch directions, monotonous delivery, and falling pitch regardless of the communicative context. Statistical analysis demonstrated a significant improvement with mean scores increasing from 15.80 to 20.90 out of 40.00 (p = .010). However, discrepancies between native speakers' and lecturers’ ratings suggested that intelligibility and naturalness may need to be considered separately in intonation instruction.