80 Jane Stuart-Smith, Eleanor Lawson and James M. Scobbie
UTI makes use of ultrasound technology designed for usual medical research,
capturing analogue video showing visual dynamic representations of tongue con-
figuration and tongue movement, usually, but not exclusively, in sagittal orienta-
tion (see Figure 8).Figure 8. Midsagittal image of the tongue surface produced using a Concept M6
medical ultrasound machine. The tongue root is to the left of the image and the tip
is to the right of the image.In our setup the ultrasound probe is held under the chin by a stabilising head-
set, and the screen displays a 2D fan-shaped image, showing the water-air inter-
face, i.e. the tongue surface, as a bright white line, thanks to the great intensity of
reflections of ultrasound pulses back to the probe. To some extent the internal
muscle structure of the tongue can also be seen. It is possible to visualize almost
the whole of the mid-sagittal shape and location of the tongue, root, dorsum,
front, and sometimes the tongue tip – though the tongue tip is often not visible
when it is raised, due to the presence of a sublingual airspace. We use specialist
software, Articulate Assistant Advanced™
, to capture, process and analyze the
data (Articulate Instruments Ltd. 2011).
Whilst UTI gives instant dynamic and static impressions of tongue movement
which are immediately informative, quantifying UTI data is challenging and tech-
niques are still under development. Data are also less direct than it might appear,
both because of the basic video frame rate (only 30 frames/sec), and the way in
which images are constructed by video-output ultrasound machines. This means
that ultrasound data are somewhat removed from actual articulation, being both
partial and processed. Nevertheless, UTI offers sociophoneticians an excellent