Articulation and acoustics of Kannada affricates: A case of geminate /ʧ/

Affricates have been observed to be problematic in phonological acquisition and disordered speech across languages, due to their relatively complex spatial and temporal articulatory patterns. Remediation of difficulties in the production of affricates requires understanding of how these sounds are typically produced. This study presents the first systematic articulatory and acoustic investigation of voiceless geminate affricate /ʧ/ in Kannada (a Dravidian language), compared to the palatal glide and the voiceless dental stop. Ultrasound data from 10 normal speakers from Mysore, India revealed that /ʧ/ is produced with the tongue shape intermediate between the palatal glide and the dental stop, and with the laminal constriction at the alveolar ridge. The observed articulatory differences are reflected in acoustic formant patterns of vowel transitions and stop/affricate bursts. Altogether, the results show that the Kannada consonant in question is an alveolopalatal affricate, supporting some of the previous descriptive phonetic accounts of the language and raising questions for further research on normal and disordered speech. The results and our survey of literature also suggest that affricates in South Asian languages tend to be phonetically variable and historically unstable compared to other consonant articulations.