Effects of Korean learners' consonant cluster reduction strategies on English speech recognition performance

This paper examines how the strategies for L2 production utilized by foreign language learners affect the performance of non-native speech recognition. Producing English consonant clusters are the most problematic for Korean learners of English because of difference between Korean and English phonotactics. The strategies of Korean learners in producing English consonant clusters entail a large amount of speech recognition errors. We have analyzed these problems based on phonetic and phonological knowledge of both languages and proposed two models focusing on vowel epenthesis and consonant deletion, respectively. These models reflect Korean learners’ cluster reduction strategies. Experimental results show that the vowel epenthesis model improves the speech recognition performance compared to the baseline; however, the consonant deletion model deteriorates the speech recognition performance. It is noteworthy that these experimental results are consistent with previous linguistic studies, which have claimed that L2 learners are more likely to avoid producing clusters by vowel epenthesis rather than by consonant deletion.