Voice Production and Pathology
This article was originally published in the August 1999 issue of CLASnotes.
In the Department of Communication Sciences and Disorders' Laryngeal Function Laboratory (located in the lower level of Dauer Hall) we not only study voice production, we help people regain it. In our efforts to combine scientific inquiry with clinical practice, we handle an interesting variety of projects:
Much of our work has focused on the study of Spasmodic Dysphonia, a rare neurological disorder that causes the voice to uncontrollably break. It makes talking effortful, and left untreated, can be very debilitating. In the lab we are examining the characteristics of this disorder, how it changes as a function of treatment and how people learn to compensate for the dysfunction. While the laboratory is dedicated to studying the physiology of this disorder, our long-term goal is to assist in developing a positive treatment outcome for patients.
One of the other major areas of inquiry in our field is determining the role of the respiratory system in producing voice. Any great singer will tell you that breath support is critical for good voice production. But what is the right amount of breath support for a singer? Does the breathing process for a singer differ from the process for a nonsinger? How do you measure someone's breathing or, for that matter, his or her pattern of breathing? Specialized instrumentation (see inset photos) for quantifying lung volume and for tracking the movement patterns of the rib cage and abdomen during speech and song allow us to gather this kind of data in the Laryngeal Function Lab. Our work indicates that, from a physiological perspective, trained singers operate differently than nonsingers, and that training a singer does indeed influence and enhance his/her pattern of breathing and voice production. Breath alterations (such as changing patterns of lung volume and rib expansion) are most typically learned by the singer in order to help develop the pressure needed to produce an adequate vocal loudness and tone. These alterations are specifically effective in preventing singers from developing larynx and other long-term voice use problems.
As part of a new Department of Defense-funded project, we are also studying why Navy divers experience a greater sensation of breathlessness when pressed to 1000 feet below sea level. Currently, these divers try to communicate the best they can with helium-altered voices and hand signals at depths that are often greater than 190 feet below sea level. Although there are unscramblers that transmit their voices to the surface, the Navy Experimental Dive Unit (NEDU) in Panama City, FL. still feels the divers are breathing with too much effort and wants our team to improve their breathing mechanics.
With the personnel at NEDU, as well as colleagues from the Department of Physiological Sciences (Paul Davenport) and Physical Therapy (Danny Martin), we are studying the divers' physical adjustments to breathing and speaking in their diving environments. The breathing and voice tests are done in a sophisticated dry chamber in Panama City. The chamber simulates atmospheric conditions of 500 and 1,000 feet below sea level.
Navy divers spend many hours conditioning their legs and arms during their current training program, and our team will enhance this regimen by creating a training component that increases respiratory strength, allowing them to breathe easier, thereby influencing their ability to do physical work and communicate simultaneously while at significant depths. We look forward to the outcome of this study, a truly collaborative effort with potential results that will influence both dive time and safety.
Such high-level scientific inquiry is critical for shaping what we do as rehabilitation specialists, and it also teaches our students that basic science is the cornerstone to clinical practice.
Credits
Writer
Christine Sapienza, Communication Sciences and Disorders
