To be able to sing or speak, about 100 different muscles in our chest, neck, jaw, tongue, and lips must work together to produce sound. Researchers investigate how all these mechanisms effortlessly work together-and how they change over time.
"The fact that we can produce all sorts of sounds and we can sing is just amazing to me," says Aaron Johnson, affiliate faculty member in the Bioimaging Science and Technology Group, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, and assistant professor in speech and hearing science at Illinois. "Sounds are produced by the vibrations of just two little pieces of tissue," he says. That's why I've devoted my whole life to studying it: I think it's just incredible."
The sound of the voice is created in the larynx, located in the neck. When we sing or speak, the vocal folds-the two small pieces of tissue-come together and, as air passes over them, they vibrate, which produces sound.
After 10 years of working as a professional singer in Chicago choruses, Johnson's passion for vocal performance stemmed into research to understand the voice and its neuromuscular system, with a particular interest in the aging voice.
"The neuromuscular system and larynx change and atrophy as we age, and this contributes to a lot of the deficits that we associate with the older voice, such as a weak, strained, or breathy voice," Johnson says. "I'm interested in understanding how these changes occur, and if interventions, like vocal training, can reverse these effects. In order to do this, I need to look at how the muscles of the larynx move in real time."
With the magnetic resonance imaging (MRI) capabilities in Beckman's Biomedical Imaging Center, Johnson can view dynamic images of vocal movement at 100 frames per second-a speed that is far more advanced than any other MRI technique in the world, according to the Center.
"Typically, MRI is able to acquire maybe 10 frames per second or so, but we are able to scan 100 frames per second, without sacrificing the quality of the images," says Brad Sutton, technical director of the Center and associate professor in bioengineering.
The researchers published their technique in the journal Magnetic Resonance in Medicine.
"In order to capture the articulation movements, 100 frames per second is necessary, and that is what makes this technique incredible," Johnson says.
"The technique excels at high spatial and temporal resolution of speech-it's both very detailed and very fast. Often you can have only one these in MR imaging," Sutton says. "We have designed a specialized acquisition method that gathers the necessary data for both space and time in two parts and then combines them to achieve high-quality, high-spatial resolution, and high-speed imaging."
[Source: Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign]
Judy O'Rourke worked as a newspaper reporter before becoming chief editor of Clinical Lab Products magazine. As a freelance writer today, she is interested in finding the story behind the latest developments in medicine and science, and in learning what lies ahead.
