Abstract
The purposes of this study are: (i) to investigate whether nine linguistic measures in the domains of phonology, fluency, lexis, and grammar are differentially correlated with comprehensibility (ease of understanding) when evaluated by four American, nine Chinese, and seven Japanese listeners of English using a 9-point scale; and (ii) to examine which of the nine linguistic measures best predict comprehensibility for each listener group. Forty-five speech samples were obtained from Japanese speakers of English. Each listener assigned a comprehensibility score on each speech token. Four experienced American teachers then assessed the nine linguistic measures observed in the collected samples by listening to the sound stimuli or reading their transcriptions. Partial correlation analysis demonstrated that phonology and fluency qualities alone are significantly correlated with comprehensibility provided by both American and Chinese listeners. However, for Japanese listeners, not only phonology and fluency aspects but also lexical and grammatical features showed significant correlations with comprehensibility. In addition, three separate stepwise multiple regression analyses revealed that intonation alone accounted for 66% of the comprehensibility by American listeners and 72% by Chinese listeners. Regarding Japanese listeners, rhythm (62%) and lexical richness (16%) were the best predictors of comprehensibility.
