A comparison of velopharyngeal function measures in dysarthria

By M. McHenry

Participants were 22 individuals, 15 males and 7 females, who had sustained a severe traumatic brain injury. While wearing the Nasometer headset (Kay Elemetrics), participants repeated a non-nasal passage at soft, typical and loud levels. Data were recorded on digital audio tape using separate oral and nasal channels. To obtain pressure-flow measures used to calculate velopharyngeal orifice area (Warren and DuBois, 1964), participants repeated ^Óhamper^Ô syllable trains at the same loudness levels. Nasal airflow, nasal air pressure, and intraoral pressure were captured and digitized. Separate Pearson product moment correlations were performed to assess the relationship between nasalance and velopharyngeal orifice area for each loudness condition. No significant relationship was found for any condition. The lowest correlation was in the soft condition. For typical loudness, in 10 of 22 cases, nasalance was abnormally high while velopharyngeal orifice area was within normal limits (i.e., < 5 mm2). In another 10 cases, nasalance results paralleled velopharyngeal orifice area. The remaining two cases evidenced atypical patterns. It is clear that differences exist between aerodynamic and acoustic assessment of velopharyngeal function. The differences may be based on task, dysarthria type, or an interaction of the two.