This is my first professional (as opposed to personal) youtube video, on my work channel for Maps of Speech. Today I’m making my debut with a scientific report on colorized schlieren images of speech air flow with and without masks. Please share widely, and encourage others to share widely. This is intended to be a worldwide release, and has been approved by the New Zealand Ministry of Business, Innovation, and Employment’s communications team, as well as our COVID-research team. In general, videos on this channel are more formal than my HoT videos, and will often be made in collaboration with whatever research team is working on the related projects. The details below this video link to three other unlisted videos that show the entirety of the schlieren videos referenced – without any audio commentary.
Frame of Colorized Schlieren data from a speaker saying “The beige hues on the waters of the loch impressed all”, no face mask.
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).
Fig. 11. Temporal dynamics of tongue curvature in the coronal plane over the entire V-/l/ interval. The brackets indicate onset (red) and coda (blue) /l/ intervals. Each bracket extends from the /l/ onset to its peak. For onset /l/s, the peak occurs earlier (at about 200 ms) than coda /l/s (at about 450 ms). A time of zero indicates the vowel onset. The 800-interval window captures the entire V-/l/ articulation in every token.
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.
