Supraglottic activity: Evidence of vocal hyperfunction or laryngeal articulation?

False vocal fold (FVF) adduction and compression of the arytenoid cartilage s to the petiole of the epiglottis in an anterior to posterior (A-P) direct ion have been thought to characterize voice disorders with abnormally incre ased muscle tension or effort, often termed hyperfunctional voice disorders . To further evaluate the association between hyperfunctional voice disorde rs and supraglottic activity we compared the incidence of static and dynami c supraglottic activity in individuals with normal laryngeal mucosa, normal voice quality, and no voice complaints to two populations: subjects with v ocal Fold nodules and subjects with complaints of dysphonia without visible vocal fold lesions, glottal incompetence, or impairment of arytenoid carti lage motion ("hyperfunctional" group). Thirty-two subjects were assigned to one of these three groups (10 control, 12 nodule, and 10 hyperfunctional). Laryngeal movements were recorded using flexible videoendoscopy while a su bject was performing speech tasks such as sustained phonation, syllable rep etitions, sentence imitations, and conversation. Samples were randomized by subject and task and rated for presence or absence of A-P and FVF compress ion. Statistically significant group differences were found For FVF compres sion across speech tasks (chi-square, p < 0.001). The control group had the smallest incidence (45%), nodule patients the next larger incidence (68%), and hyperfunctional patients the largest incidence (80%). Statistically si gnificant group differences were found for A-P compression across speech ta sks (chi-square, p < .05). The control group had the smallest incidence (74 %), nodule patients the next larger incidence (78%), and hyperfunctional pa tients the largest incidence (92%). Statistically significant task differen ces were found for the presence of FVF compression in control subjects (chi -square, p < .005), hyperfunctional patients (chi-square, p < .025), and no dule patients (chi-square, p < .001), but not for AP compression for any of the groups. A higher incidence of FVF compression was present for the spee ch tasks that included glottal stops. This context-specific variation in su praglottic activity suggested a dynamic component to FVF compression and al so explained the high proportion of FVF compression in the control group. E ach video sample was also rated for consistency of FVF or A-P compression t o explore the static and dynamic nature of supraglottic activity For sample s on which raters agreed, A-P compression was typically present consistentl y, suggesting a static component, and FVF compression inconsistently, sugge sting a dynamic component, for all three groups (chi-square, p < .001). The se Findings do not support previous suggestions that supraglottic activity may be a precursor to developing vocal fold nodules, as the nodule patients did not exhibit a higher incidence or consistency of A-P or FVF compressio n than patients with hyperfunctional voicing patterns in this study. Subjec ts in the hyperfunctional voice group were Found to have static components of FVF and A-P compression. The presence of FVF compression in speech tasks that included glottal stops in the control group suggests an articulatory function at the laryngeal level.