Yao, He, Chen, Zhu (2024) A Meta-Analysis of Second Language Phonetic Training

Phonetic training

This meta-analysis seeks to answer these questions:

1. What is the effect of L2 phonetic training?

2. What factors moderate the effectiveness of L2 phonetic training? (education, proficiency, training approach, training stimuli, mode of delivery, phonetic subcompetence).

The meta-analysis looked at studies that met the following criteria. The study had to:

1. be an empirical phonetic training study;

2. look at L2 segments, not suprasegmentals;

3. report on accuracy and/or response time of participants' perception and/or production;

4. look at second or foreign language phonetic training;

5. have participants without speech, language, or hearing impairments.

Based on these criteria, the meta-analysis included 65 studies.

Data analyses were performed using Comprehensive Meta-analysis Version 3.0 (Biostat Inc.) Cohen's d was used to compare effect sizes treatment groups with control groups. To assess publication bias, Fail-Safe N and Trim and Fill analyses were conducted.

Results

The effect sizes between groups with phonetic training versus groups without was large (Cohen's d = 0.762), indicating that there is a larger difference between the groups relative to the variability in the data.

Moderator analyses were conducted to explore potential factors influencing the effects of L2 phonetic training. Results found highly significant differences (p < .001) in educational levels (university, language institute, high school, pre-middle school, unspecified), training approach (perceptual, production, combined), mode of delivery (auditory, visual, audiovisual), outcome measure ( identification, discrimination, both identification and discrimination, subjective perception judgement, objective acoustic measurement), and phonetic subcompetence (perception, production). Significant differences (p < .05) were found for training stimuli (natural, synthetic, combined). Language proficiency (advanced, intermediate, novice, unspecified) was not significant.

Educational levels: The largest effects were observed at the high school level.

Training approach: Perceptual training yielded the largest effect size.

Mode of delivery: The audiovisual mode yielded the largest effect size.

Outcome measure: Identification teasks generated the largest effect size.

Phonetic subcompetence: Perception yielded the largest effect size.

Training stimuli: Synthetic stimuli yielded the largest effect size.