"We're using technological tools to get better data on how the vocal tract moves during speech," said study author Dani Byrd, an associate professor of linguistics and director of the USC Phonetics Laboratory in the USC College of Letters, Arts and Sciences.
"Magnetic resonance imaging allows us to look at movies of the entire vocal tract in action, something no one's been able to see in real time before now," Byrd said.
The team reported successful development and use of real-time MRI to create high-resolution movies of the vocal system in April's Journal of the Acoustical Society of America.
By helping to clarify ways that humans produce normal speech, the new technique may help people learn a foreign language, teach machines to speak more naturally and possibly suggest therapy for those with speech problems due to stroke.
The advance comes as a result of an interdisciplinary collaboration led by Byrd and electrical engineer Shrikanth Narayanan, an associate professor in the USC Viterbi School of Engineering who focuses his research at the interface of speech, engineering and computer science.
The team also drew on the talents of MRI systems researcher Krishna Nayak, an assistant professor of electrical engineering and medicine; Sungbok Lee, a research scientist in linguistics and electrical engineering, and Abhinav Sethy of electrical engineering.
MRI has been used for in speech research for more than a decade, said Byrd, who focuses her research on the production, perception and physical properties of speech sounds.
Up to now, MRI primarily has recorded still images of the dynamic vocal tract, data that have been useful but limited in telling researchers about the timing of speech.