Cho, Hyesun. 2017. An acoustical analysis of English post-alveolar fricatives and affricates produced by Korean and English speakers. Studies in Phonetics, Phonology and Morphology 23.2. 293-324. 

This study examines acoustic properties of English post-alveolar affricates and fricatives /ʃ, ʒ, tʃ, dʒ/ produced by Korean learners of English. Five Korean learners of English and three native speakers of North American English were recorded reading materials including /ʃ, ʒ, tʃ, dʒ/. The acoustic properties examined are the ones that are known to distinguish voicing or manner contrasts: duration (closure, frication), intensity (closure, frication), frication characteristics (center of gravity (CoG), F2 and F3 at the frication release), and preceding vowel duration. The results are mostly consistent with previous studies, showing the characteristics of Korean speakers’ production of these sounds: weaker voicing in the voiced segments (indicated by lower closure intensity, higher CoG in the voiced fricatives), more palatalization (higher F2), and less lip rounding (higher F3). (Dankook University)