Reconsidering lateral vocalisation: Evidence from perception and production of Australian English /l/.

Lateral vocalisation is assumed to arise from changes in coronal articulation but is typically characterised perceptually without linking the vocalised percept to a coronal articulation. Therefore, we examined how listeners' perception of coda /l/ as vocalised relates to coronal closure. Perceptual stimuli were acquired by recording laterals produced by six speakers of Australian English using electromagnetic articulography (EMA). Tongue tip closure was monitored for each lateral in the EMA data. Increased incidence of incomplete coronal closure was found in coda /l/ relative to onset /l/. Having verified that the dataset included /l/ tokens produced with incomplete coronal closure-a primary articulatory cue of vocalised /l/-we conducted a perception study in which four highly experienced auditors rated each coda /l/ token from vocalised (3) to non-vocalised (0). An ordinal mixed model showed that increased tongue tip (TT) aperture and delay correlated with vocalised percept, but auditors ratings were characterised by a lack of inter-rater reliability. While the correlation between increased TT aperture, delay, and vocalised percept shows that there is some reliability in auditory classification, variation between auditors suggests that listeners may be sensitive to different sets of cues associated with lateral vocalisation that are not yet entirely understood.

Spectral contrast reduction in Australian English /l/-final rimes.

Vowel contrasts may be reduced or neutralized before coda laterals in English [Bernard (1985). The Cultivated Australian: Festschrift in Honour of Arthur Delbridge, pp. 319-332; Labov, Ash, and Boberg (2008). The Atlas of North American English, Phonetics and Sound Change (Gruyter Mouton, Berlin); Palethorpe and Cox (2003). International Seminar on Speech Production (Macquaire University, Sydney, Australia)], but the acoustic characteristics of vowel-lateral interaction in Australian English (AusE) rimes have not been systematically examined. Spectral and temporal properties of 16 pre-lateral and 16 pre-obstruent vowels produced by 29 speakers of AusE were compared. Acoustic vowel similarity in both environments was captured using random forest classification and hierarchical cluster analysis of the first three DCT coefficients of F1, F2, and F3, and duration values. Vowels preceding /l/ codas showed overall increased confusability compared to vowels preceding /d/ codas. In particular, reduced spectral contrast was found for the rime pairs /iːl-ɪl/ (feel-fill), /ʉːl-ʊl/ (fool-full), /əʉl-ɔl/ (dole-doll), and /æɔl-æl/ (howl-Hal). Potential articulatory explanations and implications for sound change are discussed.

Characterizing spoken responses in masked-onset priming of reading aloud using articulography.

A key method for studying articulatory planning at different levels of phonological organization is masked-onset priming. In previous work using that paradigm the dependent variable has been acoustic response time (RT). We used electromagnetic articulography to measure articulatory RTs and the articulatory properties of speech gestures in non-word production in a masked-onset priming experiment. Initiation of articulation preceded acoustic response onset by 199 ms, but the acoustic lag varied by up to 63 ms, depending on the phonological structure of the target. Onset priming affected articulatory response latency, but had no effect on gestural duration, inter-gestural coordination, or articulatory velocity. This is consistent with an account of the masked-onset priming effect in which the computation from orthography of an abstract phonological representation of the target is initiated earlier in the primed than in the unprimed condition. We discuss the implications of these findings for models of speech production and the scope of articulatory planning and execution.