Featured Research

from universities, journals, and other organizations

Air flows in mechanical device reveal secrets of speech pathology

Date:
November 21, 2010
Source:
American Institute of Physics
Summary:
A mechanical model of human vocal folds and new observations may lead to new devices to help people afflicted with vocal fold paralysis.

From a baby's first blurted "bowl!'" for the word "ball" to the whispered goodbye of a beloved elder, the capacity for complex vocalizations is one of humankind's most remarkable attributes -- and perhaps one we take for granted most of our lives.

Not so for people who are afflicted with paralysis to their vocal folds and who suffer the social stigma of affected speech. Nor so for engineering professor Michael Plesniak and post-doctoral researcher Byron Erath at the George Washington University (GWU) Biofluid Dynamics Laboratory In Washington, D.C., and their colleague professor Sean Peterson at the University of Waterloo. To them, the ability to vocalize is such a prized ability that they have built a mechanical model of human vocal folds.

At the American Physical Society Division of Fluid Dynamics (DFD) meeting in Long Beach, CA, the researchers are reporting their discovery of how asymmetrical airflow impacts normal and diseased vocal fold motion -- observations that may lead to new devices to help those who cannot take for granted their ability to vocalize.

"Potential application of this finding includes assisting otolaryngologists to optimize surgical procedures to correct vocal fold paralysis with an implant that changes the position of the damaged vocal fold," Plesniak says.

Vocal folds, commonly known as vocal cords, are the vibrating structures of the phonatory process that stretch across the larynx, and are driven by air expelled from the lungs. Variability in the physics of sound production from the vocal folds can mark the difference between communication that connects people and enriches their lives and speech so impaired it isolates and estranges.

In the GWU team's most recent investigation, they found that asymmetric flow develops when there is an adverse pressure gradient. Under these conditions, the glottal jet separates from one vocal fold and attaches to the opposing one, disrupting the pressure forces that drive vocal fold motion. This change can have devastating impacts on speech.

"In the past, many investigators have assumed air flow is symmetrical over the vocal folds," explains Erath. "We've discovered that this is not always the case."

While most people's vocal folds tolerate the asymmetry very well, the degree of asymmetry becomes especially important in speech pathologies where tissue stiffness is affected by diseases such as unilateral vocal fold paralysis. In these cases, the asymmetric flow interacts with the damaged vocal fold, causing chaotic irregular vibrations.

Data from the GWU team suggests that devising an implant material with tissue properties that mimic those of the voice apparatus is key to restoring the good vibrations that are the foundation of intelligible speech.

The presentation "The impact of asymmetric flows on pathological speech was given on November 21, 2010


Story Source:

The above story is based on materials provided by American Institute of Physics. Note: Materials may be edited for content and length.


Cite This Page:

American Institute of Physics. "Air flows in mechanical device reveal secrets of speech pathology." ScienceDaily. ScienceDaily, 21 November 2010. <www.sciencedaily.com/releases/2010/11/101121122535.htm>.
American Institute of Physics. (2010, November 21). Air flows in mechanical device reveal secrets of speech pathology. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2010/11/101121122535.htm
American Institute of Physics. "Air flows in mechanical device reveal secrets of speech pathology." ScienceDaily. www.sciencedaily.com/releases/2010/11/101121122535.htm (accessed September 22, 2014).

Share This



More Health & Medicine News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Global Ebola Aid Increasing But Critics Say It's Late

Global Ebola Aid Increasing But Critics Say It's Late

Newsy (Sep. 21, 2014) More than 100 tons of medical supplies were sent to West Africa on Saturday, but aid workers say the global response is still sluggish. Video provided by Newsy
Powered by NewsLook.com
Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins