Penn State scientists have recently identified new clues that they think will help improving speech of people with dysarthria, a speech disorder that causes slurred speech, slowed speech, abnormal pitch, and rhythm, changes in voice quality and limited tongue, lip or jaw movement.
According to the reports, Dysarthria has the most astounding commonness rate among a wide range of gained neurogenic communication disorders.
Scientists asked 22 study participants to read a paragraph that includes all sounds in American English. During this, they analyzed the size of the space used by each articulator (tongue, lip, and jaw). Scientists found that in people with more severe dysarthria due to ALS, tongue range of motion is reduced, while a range of motion for the lower lip and jaw both increase.
Scientists hope that their findings could aid in estimating speech dysfunction and determining the treatment to improve speech in patients with ALS or other neurological conditions, such as Parkinson’s disease, cerebral palsy and multiple sclerosis.
Jimin Lee, assistant professor of communication sciences and disorders at Penn State said, “This highlights the importance of range of motion for speech production, and indicates that if we change range of motion in people with the disorder, if we ask them to expand their overall workspace for speech production, then we may see more understandable speech.”
“The difference in a range of motion in people with dysarthria has been largely assumed but had not been directly tested. It is exciting to provide empirical evidence based on the movement of articulators. Additionally, the study provides important evidence regarding the different amount of impairment across articulators as well as its high sensitivity to the severity of dysarthria. This has values for both intervention and diagnosis of dysarthria.”
During this study, scientists used a tool called a 3-D, portable electromagnetic articulography- also called the Wave system. The tool measures the movement of tongue, lips, and jaw using an electromagnetic field while simultaneously recording acoustic signals.
In addition, there were sensors attached to patient’s tongue to trace its movement during speech production. The tool also is connected to a microphone and computer, which stores the data.
Lee said, “The ultimate goal is to develop an effective intervention for people with dysarthria. In order to help people with ALS use their speech as long as possible, we will continue to identify what types of movement will generate speech signals that are easier to understand.”
“The majority of people with ALS lose their speech during the progression of the disease. Their tongue function deteriorates fast but the jaw function is relatively preserved, and these two articulators work together for speech production. Thus, we are trying to find a way to enhance their speech intelligibility by looking at tongue and jaw movement characteristics simultaneously.”
The study, which included 22 ALS patients, is an extension of a previous study that involved 14 people with ALS. The American Journal of Speech-Language Pathology published the latest findings online this week.