Ultrasound Tongue Imaging

How LinguaSound 3D works

Ultrasound tongue imaging (UTI) is a non-invasive technique used to view the shape, position and movements of the tongue during speech. It relies on the use of high-frequency sound waves (ultrasound) to create real-time images of the tongue's internal structures and movements. A thin layer of gel is applied to an ultrasound probe (transducer), which is placed beneath the chin. The transducer emits sound waves that travel through the tissues and are reflected back when they encounter different structures within the tongue.

By analysing the time taken for the sound waves to return and their intensity, the ultrasound scanner generates dynamic images of the tongue's shape and motion. These ultrasound images are transferred to the host computer via USB, where a contour tracking algorithm is applied. Finally, the extracted tongue contours are used to animate a 3D model of the tongue.

Hard-palate estimation

Due to the air above the tongue surface reflecting sound waves back to the transducer, conventional ultrasound tongue imaging does not easily capture the hard-palate. LinguaSound 3D can be configured to record the extent of the tongue when it touches the hard-palate, allowing its position and size to be estimated. This procedure is illustrated in the following video:

Comparing conventional ultrasound tongue imaging with LinguaSound 3D

LinguaSound 3D, which is language independent, can simplify the interpretation of conventional ultrasound tongue imaging. A comparison of both imaging techniques is illustrated below for a normal English speaker:

	Conventional ultrasound tongue imaging	LinguaSound 3D
Velar Stop /k/
Alveolar Stop /d/
Retroflex /r/
High-Front Vowel /i/
Low-Back Vowel /a/

PC-based ultrasound scanner

LinguaSound 3D uses a lightweight and compact PC-based ultrasound scanner that connects to the host computer via USB. Depending on the scan depth, frame rates of up to 120 frames per second can be achieved. The scanner is compatible with 20mm and 10mm ultrasound probes for use with adults and small children. It also uses fanless technology for silent operation, and supports a wealth of advanced image processing features.

Ultrasound probes

LinguaSound 3D software

The LinguaSound 3D software is Windows 64-bit compatible. It combines ultrasound imaging, contour tracking and 3D modelling techniques to illustrate the shape, position and movements of the tongue in real-time. The 3D model consists of the tongue, hard-palate and teeth. The transparency of these articulators can be adjusted to reveal hidden structures, and the model can be rotated 360°.

Features include:

• Preview ultrasound and 3D model in real-time (up to 70 FPS)
• Record up to 120 FPS with fully synchronised audio
• Auditory playback of speech production
• 360° photorealistic and stylised views
• Adjustable 3D model transparency
• Configurable ultrasound scanner and probe
• Windows 11, 10, 8.1 (64-bit) compatible

System requirements

Supported operating systems	Windows 11, 10, 8.1 (64-bit)
Supported computers	Desktop, laptop
CPU	Intel(R) i5, i7, i9; 1.80GHz or better
RAM	Minimum 8 GB
Size on disk	200 MB
Ultrasound connectivity	USB 3.0
Ultrasound power	USB or external supply