Transcription-based and acoustic analyses of rhotic vowels produced by children with and without speech sound disorders: Further analyses from the Memphis Vowel Project

Abstract

The acquisition of rhotic monophthongs (/ɝ/ and /ɚ/) and diphthongs (/ɪ͡ɚ, ɛ͡ɚ, ɔ͡ɚ and ɑ͡ɚ/) was examined in 3- and 4-year-old children with and without speech sound disorders (SSDs), using both transcription-based and acoustic analyses. African–American (AA) and European–American (EA) participants (n = 40) with and without SSD were selected from archival data collected as part of the Memphis Vowel Project. Dialect variation influenced rhotic vowels differently for EA and AA children, thus their data were reported separately. Transcription-based analyses showed wide variation in the accuracy of different rhotic vowels. The most frequent error pattern for children with SSD was Derhoticization to a Back Rounded Vowel (e.g. /ɝ/ → [ʊ]; /ɪ͡ɚ/ → [ɪ͡о]). Rhotic diphthong reduction errors were less frequent; however, Coalesence (/ɑ͡ɚ/ → [ɔ]) was often observed for /ɑ͡ɚ/. F2, F3 and F3-F2 spectral movement patterns revealed differences between productions transcribed as correct and incorrect.

• Children
• phonological acquisition
• phonological disorder
• rhotic vowels

Acknowledgements

Special thanks to Mary Berni Hendry and Kristi Estes for data collection, transcription and project management, and to the numerous other research associates and graduate students who contributed to the Memphis Vowel Project. Thanks also to Janice Bedard who contributed to data coding for acoustic analysis.