Examining the extent of anticipatory coronal coarticulation: A long-term average spectrum analysis

Abstract

Phonetic studies of English liquids /r/ and /l/ have shown these consonants can exert strong coarticulatory effects on both adjacent and non-adjacent vowels. The current study investigated local and long-range effects of coronals /l/, /r/, and /d/ in Canadian English. Fourteen speakers were recorded reading the sentences 'We thought it might be a ram/lamb/dam/ham'. Formants F1-F3 and long-term average spectra (LTAS) of 5 vowels preceding the target consonants were calculated and compared to baseline values. The results revealed significant differences between the coronal consonants and the control (/h/) in up to 4 preceding syllables. Formant differences in non-adjacent syllables were limited to F3 (lower for /r/ than the other consonants) and were attenuated in stressed syllables. Non-adjacent LTAS differences were overall more robust, but primarily differentiated between coronals and the non-coronal /h/. Overall, /r/ showed the greatest effect on non-adjacent preceding vowels, followed by /l/, and then by /d/. The formant and LTAS methods appear to capture somewhat different, yet equally important aspects of local and long-range coarticulation. The LTAS findings suggest that higher-frequency information, while generally disregarded for speech, may contain significant coarticulatory information.