1. Biomechanical modeling of the human vocal tract.
An ongoing collaboration with Electrical and Computer Engineering beginning in 2000 has led to the development of ArtiSynth (www.artisynth.org), a state-of-the-art biomechanical simulation platform focused on modeling the human vocal tract. This highly interdisciplinary research has not only become an invaluable tool for basic speech research, but is providing new possibilities for modeling oral surgery, computer animation, audiovisual telecommunications, and other industry applications.
2. The influence of the tactile modality in speech perception.
This stream of research shows that humans engaging in speech perception readily integrate event-specific tactile information from all over the body (neck, hand, ankle), suggesting a whole-body speech perception system. Results have also uncovered an asymmetry in the temporal window of perception of speech sound versus air flow, corresponding to the temporal difference between the speed of sound and the speed of speech-initiated air flow, analogous to the relationship between the speech of sound and light in audiovisual speech perception. This line of research has been funded in part through a collaborative NIH grant (Doug Whalen, PI) at Haskins Laboratories.
3. Ultrasound as a tool for imaging the tongue during speech.
Ultrasound imaging technology, being both portable and less invasive than other methods of physiological data collection, is enabling researchers to study the role of the tongue in speech with hitherto under-studied populations, including disordered populations, children, and speakers of endangered or seldom-studied (e.g., First Nations) languages, and more recently, speakers with cosmetically bifurcated tongues. ISRL efforts to broaden the applications of ultrasound imaging in speech have played prominently in this major transformation in the way speech articulation is being studied, and have helped spur the creation of dozens of new ultrasound speech labs worldwide. As part of this work, we co-founded “UltraFest”, an international workshop on ultrasound applications in speech, which is now counting a half-dozen meetings.
4. The use of visual biofeedback to treat speech and hearing disorders.
The ISRL has developed techniques using feedback from ultrasound and electropalatography in speech intervention for deaf, hard of hearing and speech disordered populations. A number of publications (mostly in collaboration with May Bernhardt and Penelope Bacsfalvi, Audiology & Speech Sciences) have shown these techniques to be extremely effective, both in the short and long term. This research has spurred a great deal of interest in this new area, particularly with respect to the use of ultrasound in speech therapy, including a program to bring ultrasound intervention to rural areas. Related research in quantifying tongue shapes has the potential to provide early signs and ongoing diagnostics that may help clarify links between speech and motor development in children.