UC Team Studies Causes Behind Voice Disorders
Published January 2010
Though we use it every day, our voice and the mechanisms behind it remain a mystery for many physicians, especially so when severe disorders cause patients to lose their voice entirely.
With a new five-year, $2.5 million grant from the National Institutes of Health, a team of UC researchers will continue interdisciplinary partnerships to study the causes behind voice disorders and the most effective ways to treat them.
The grant, awarded to laryngologist Sid Khosla, MD, of the otolaryngology–head and neck surgery department at UC, includes aerospace engineer Ephraim Gutmark, PhD, engineering and otolaryngology; Suzanne Boyce, PhD, communication sciences and disorders; and Shanmugam Murugappan, PhD, otolaryngology.
The team is seeking to prove a new hypothesis about the production of voice: that vortices, or pockets of rotating air near the vocal cords, are necessary for normal voice production. It is the modification or suppression of those vortices in laryngeal disease, researchers think, that leads to abnormal voice.
In normal voice production, or phonation, says Khosla, vocal cords come together while air flowing over them produces vibration. But he says researchers haven’t been able to confirm exactly how the air creates the vibration.
Past research points to vortices as the key ingredient. Vortices were known to produce sound in jet engines and suction in tornados, but it wasn’t until Khosla and Gutmark developed a method to identify vortices in a larynx that they could measure the forces they produced.
In that research, the team brought in techniques Gutmark had used to study airflow inside jet engines, when the goal was reducing jet noise.
"Now our purpose is different, but the physics is the same,” says Gutmark. "Once you understand how airflow structure produces acoustics, you can either make the acoustics quieter, for jets, or make them stronger, for voices.”
Khosla and his team will now study how vortices are affected in certain voice pathologies and common treatments for them.
If one of the tested treatments sufficiently restores vortices in the airway, then it could stand the best chance of restoring normal vibrations—and normal voice.
"It’s not only about determining that these vortices are there and they play a crucial role,” says Khosla, "but it’s also about determining the best ways to restore them for these patients.”