Effects of rhythm and phrase-final lengthening on word-spotting in Korean

A word-spotting experiment was conducted to investigate whether rhythmic consistency and phrase-final lengthening facilitate performance in Korean. Listeners had to spot disyllabic and trisyllabic words in nonsense strings organized in phrases with either the same or variable syllable count; phrase-final lengthening was absent, or occurring either in all phrases or only in the phrase immediately preceding the target. The results show that, for disyllabic targets, inconsistent syllable count and lengthening before the target led to fewer errors. For trisyllabic targets, accuracy was at ceiling, but final lengthening in all phrases reduced reaction times. The results imply that both rhythmic consistency (i.e., regular syllable count) and phrase-final lengthening play a role in word-spotting and, by extension, in speech processing in Korean, as in other languages. However, the results also reflect the language specific role of prosodic cues. First, the cues here were used primarily with disyllabic targets, which were cognitively more demanding to process partly due to their high phonological neighborhood density. Second, the facilitating effect of rhythmic consistency was weak, possibly because strict consistency is not present in spoken Korean. Overall, rhythmic consistency facilitated spotting when targets mapped onto phrases, confirming the importance of phrasal organization in Korean speech processing.