Under this grant, modeling assumptions that are commonly applied in models of human phonation (fluid-induced vibrations of the vocal folds) will be systematically evaluated. Because of the inaccessibility of the larynx, modeling has long been a primary component of voice research. Speech models seek to simplify the complicated fluid-structure interactions of human voice production while still capturing the relevant physics. However, untested modeling assumptions limit the accuracy of such models. Ultimately, highly accurate models will be transformative to clinical diagnosis, treatment, and pre-surgical planning of voice disorders. The prevalence of voice disorders in the general population is estimated to be as high as 30%, and is twice as high among professionals who lecture regularly, such as educators. Each year, billions of dollars in lost productivity costs is due to vocal ailments.
The goal of this project is to assess the validity of untested modeling assumptions that are routinely employed. Fluid flow investigations will be performed in a 7.5 times life-size controllable dynamic model of the vocal folds. Viscous flow phenomena within the glottis will be studied via spatial and temporal flow field data using Particle Image Velocimetry (PIV) and Laser Doppler Velocimetry (LDV). Parametric structural analysis will be performed to determine the sensitivity of the vocal fold structure to eight geometric and six tissue parameters of several have never been measured. The knowledge obtained from this study will increase the accuracy and validity of future models, eventually leading to the creation of clinically relevant models of human speech. In addition to speech production, the results will be relevant to the more general fields of fluid-structure interactions, and biomedical engineering.
The existing outreach programs at Purdue University will ensure that in addition to engineering and societal impacts, the research will have a broader impact on participation of underrepresented groups, undergraduate research participation, and K-12 outreach programs. The Summer Undergraduate Research Fellowship (SURF) program at Purdue University facilitates meaningful guided research for undergraduate students, in which female and minority participation is especially encouraged by Purdue's Minority Engineering organization. Participation in engineering outreach programs such as "Imagination Station", "Middle School Minds", and EPICS at Purdue University will facilitate the exposure of K-12 students to the excitement of engineering at a young age. A functional model of the human speech process created in conjunction with EPICS will be used for instruction in undergraduate Speech Language and Hearing Research (SLHS) classes.
