Hyperfunctional voice disorders (HVDs) are hard to describe but easy to hear. People with the condition produce a grab-bag of forms of unusual voice behaviors that make them more difficult to follow. Nodules on the vocal cords may trigger the condition, but it may linger after the nodules are removed by surgery. Voice exercises or other treatments sometimes work and sometimes do not.
And although HVDs are the most common class of voice disorders, afflicting about 3% of the U.S. population, their causes are not well understood. Doctors typically attribute the condition to emotional stress that affects the performance of muscles involved in speech.
A study by researchers at Boston University College of Health & Rehabilitation Sciences: Sargent College, however, suggests that a neurological problem affecting those muscles also can be to blame.
“We show the first evidence that some HVDs may be due to a motor control disorder, in which patients improperly process what they hear,” says Cara Stepp, an assistant professor of speech, language and hearing sciences at Sargent College. “This is a very small study, but it’s important because no one previously showed a neurological cause for this condition.”
“Calling this condition ‘hyperfunctional’ suggests that it is something that you should just be able to stop doing, but that’s clearly not true,” says Stepp, the lead author on a paper about the research in the Journal of Speech, Language, and Hearing Research.
In some cases, she notes, people can regain their normal voices after rigorous massages or other treatments, but these successes are often followed by a relapse of the condition.