Effect of Pitch Range Expansion Training on Perception of American English Question Intonation by Iranian EFL Learners

Perceptual development of English intonation remains challenging for Iranian EFL learners due to systematic L1–L2 prosodic differences. Adopting a quasi-experimental pretest-posttest control-group design with a sequential mixed-methods component (quantitative measures followed by qualitative interviews to interpret the findings), this study investigates the effects of pitch-range expansion training on Iranian EFL learners’ perception of English question intonation, along with their metalinguistic awareness and experiential reflections. Sixty intermediate learners, homogenized via the Oxford Quick Placement Test, were randomly assigned to experimental and control groups. In addition to the regular communicative curriculum, the experimental group underwent a seven-week training intervention (delivered in biweekly 20 min sessions) using Praat (Version 6.3.090) to develop pitch-range perception. Data collection utilized an intonation perception test (pre/post), an Intonation Awareness Questionnaire (IAQ), and semi-structured interviews. Quantitative analyses (ANCOVA and three-factor mixed ANOVA) revealed that the experimental group significantly outperformed the control group in overall perception accuracy, with a notably larger improvement for yes/no questions than for wh-questions. Furthermore, the experimental group demonstrated a significant increase in self-reported metalinguistic awareness from pre-test to post-test. Qualitative thematic analysis corroborated these findings, with participants reporting that visual feedback made intonation tangible and helped ease their listening anxiety. These findings highlight the efficacy of visually supported prosodic training in recalibrating L2 perceptual patterns and enhancing metacognitive awareness in EFL contexts.