Jia Ying, Jason A. Shaw, Christopher Carignan, Michael Proctor, myself, and Catherine T. Best just published Evidence for active control of tongue lateralization in Australian English /l/. Most research on /l/ articulation has looked at motion timing along the midline, or midsagittal plane. This study compares that information to motion on the sides of the tongue. It focuses on Australian English (AusE), using three-dimensional electromagnetic articulography (3D EMA).
The articulatory analyses show: 1) consistent with past work, the timing lag between mid-sagittal tongue tip and tongue body gestures differs for syllable onsets and codas, and for different vowels.
2) The lateral channel is formed by tilting the tongue to the left/right side of the oral cavity as opposed to curving the tongue within the coronal plane
3) the timing of lateral channel formation relative to the tongue body gesture is consistent across syllable positions and vowel contexts – even though temporal lag between tongue tip and tongue body gestures varies.
This last result suggests that lateral channel formation is actively controlled as opposed to resulting as a passive consequence of tongue stretching. These results are interpreted as evidence that the formation of the lateral channel is a primary articulatory goal of /l/ production in AusE.