Investigating the effects of phonological neighborhood density, word frequency, and phoneme confusability on the English word recognition by native speakers of Japanese

This study aims to bridge the gap between previous research on the impact of phonological neighborhood density on word identification, which did not consider phoneme confusability, and studies on phoneme identification and discrimination, which did not account for the effects of phonological neighborhood density. Native Japanese listeners participated in this study, where they were tasked with identifying monosyllabic and disyllabic English words. The words varied in both phonological neighborhood density and word frequency and were produced by native speakers of American English and Japanese. Participants responded by typing the words they heard. The findings of this study indicated that there were no significant effects of phonological neighborhood density on word identification. However, frequent words were identified with greater accuracy compared to infrequent words. Moreover, words produced by native speakers of American English were more accurately identified than those produced by Japanese speakers. Japanese listeners' inaccurate perception of phonemes has resulted in word identification errors in both dense and sparse phonological neighborhoods. For example, they often mistakenly identify /l/ as /r/ and vice versa. Low and central vowels /æ, ɑ, ʌ/ are frequently misidentified as one another. These confusions are commonly observed among Japanese learners of English.