A Model of Prosodic Alignment for Second Language Fluency Development

Thesis Abstract

This study investigates how prosodic alignment between learners and native speakers can serve as a mechanism for enhancing second language fluency, addressing persistent gaps in the acquisition of rhythm, intonation, and speech timing that contribute to perceived non-nativeness and reduced communicative efficiency. The problem centers on limited integrative models that connect real-time prosodic alignment processes with measurable fluency outcomes across pragmatic and interactional contexts. The aim is to develop and validate a formal model of prosodic alignment that predicts fluency gains in second language (L2) speakers and to identify the conditions under which alignment exerts the strongest effect. Specific objectives are (1) to operationalize prosodic alignment in terms of timing, pitch contour synchrony, and rhythm compatibility; (2) to examine the relationship between alignment and fluency indicators (speech rate, mean length of utterance, and disfluency rate) in task-based conversations; (3) to test the mediating role of perceived communicative ease and listening comprehension on fluency outcomes; (4) to compare alignment effects across learner proficiency levels and L1 backgrounds; and (5) to integrate findings within a theoretical framework that combines Dynamic Systems Theory and Prosodic Transfer Theory to propose a robust, testable model. A mixed-methods design is employed. The quantitative strand uses a quasi-experimental setup with 120 intermediate-to-advanced L2 English speakers, stratified by L1 typology (e.g., Romance, Slavic, and East Asian) and proficiency (CEFR B2–C1). Participants are randomly assigned to an alignment-enhanced training condition or a control condition receiving conventional pronunciation and fluency-focused instruction for eight weeks (16 sessions). Data collection includes pre- and post-tests comprising a 10-minute spontaneous dialogue, a structured reading passage, and a picture description task, recorded in high-fidelity studio conditions. Prosodic alignment is operationalized through automated acoustic analyses, extracting timing alignment (onset-to-onset synchrony, speech tempo convergence), pitch alignment (F0 contour correlation, mean F0 convergence), and rhythmic compatibility (stress-tower alignment, syllable-turation). Fluency measures include speaking rate (syllables per minute), articulation rate, mean length of utterance, and disfluency distribution. Additionally, a standardized perceived communicative ease scale is administered after each interaction. Analyses will employ hierarchical linear modeling to assess the impact of alignment on fluency outcomes while controlling for proficiency and L1 background; mediation analyses will test whether perceived ease and listening comprehension explain the alignment-fluency link. The qualitative strand comprises semi-structured interviews with 30 participants from the training condition to elicit learners’ subjective experiences of alignment cues and strategies, analyzed via thematic analysis to triangulate quantitative findings and identify contextual factors. The study anticipates that higher degrees of prosodic alignment will significantly predict improvements in fluency indicators, with stronger effects for learners at the upper end of the proficiency range and for L1 groups with prosodic similarities to English. It is expected that perceived communicative ease will partially mediate this relationship, highlighting alignment’s role in reducing processing load and facilitating smoother turn-taking. The research contributes to knowledge by operationalizing a dynamic, interaction-driven model of prosodic alignment within L2 development, integrating Dynamic Systems Theory with Prosodic Transfer Theory to account for variability, feedback, and stability in fluency growth. It advances methodological approaches by combining automated acoustic metrics with robust statistical modeling and learner perspectives, offering a replicable protocol for future cross-linguistic investigations. Practical implications include informing pedagogical design for alignment-focused curricula, real-time feedback tools, and conversational practice activities that foreground prosodic synchrony as a channel for fluency enhancement. The study concludes that structured alignment training yields durable fluency gains beyond surface-level pronunciation, with maximal benefits achieved when instruction leverages authentic interactive contexts and tailors feedback to learners’ L1 prosodic repertoires. Recommendations are provided for curriculum developers to incorporate prosodic alignment modules, for language assessment to include prosody-based fluency metrics, and for further research to explore alignment dynamics across additional languages and communicative domains such as business, medical, and academic discourse.