Effects of Subsegmental Features on Vowel Perception in L2 Phonotactic Contexts

Abstract

　　The aim of this study is to examine whether the perception of an illusory vowel in illegal phonotactic contexts in listeners’ native language (L1) is caused by L1 phonotactic constraints or by subsegmental information, such as amplitude and voicing. In addition, whether the perception differs depending on the level of L2 proficiency was investigated. Experiment 1 (an ABX task) and Experiment 2 (a forced choice task) were carried out to examine participants’ perception of the phonetic information in non-words in both legal and illegal phonotactic contexts (i.e., V1C1C2V2 and V1C1UC2V2) for native Japanese speakers with different levels of English proficiency. In Experiment 3, phonetic contexts of the stimuli were manipulated with pre-obstruent voicing (POV) by eliminating it in steps and varying the amplitude without changing the phonotactics to examine how subsegmental features affect the recognition of non-words. The results showed that POV is likely to affect a listener’s perception rather than phonotactic constraints in L1. This study has provided a concrete acoustic factor which affects Japanese English learners and evidence of development of L2 perception at the syllable level, which has contributed to revealing the mechanism of L2 learners’ speech processing.