Background: This thesis reports the findings of three projects that included pupillometric and auditory-perceptual evaluation of three voice quality features (strain, roughness, and breathiness, respectively), and measurement of perceived listening effort. Methods: In the first study, speech samples from individuals with adductor spasmodic dysphonia (AdSD) were perceptually evaluated by both naïve and experienced listeners on the feature of vocal strain and listening effort. In the second project, speech samples of postlaryngectomy tracheoesophageal (TE) speakers were rated by two groups of naïve listeners on vocal roughness and listening effort; one group was provided with audio anchors, the other without. The final study focused on perceptual evaluation of breathiness and listening effort in talkers with vocal fold paralysis (VFP). The VFP speech samples were rated by two groups (with and without audio anchors). In all three studies, listeners’ pupillary responses also were collected (EyeLink 1000) while listening to and perceptually rating voice stimuli. Findings: Data obtained from the pupillary assessment, peak pupil dilation (PPD), may indicate a listener’s cognitive load when perceptually evaluating disordered voices. Results revealed high correlations between each of the voice dimensions and listening effort. Also, various degrees of correlations were observed between perceptual ratings and PPD. In the first study, high correlations were found between PPD and perceptual ratings for naïve listeners. A listener’s previous exposure and training evoked different pupillary behavior when compared to naïve listeners. In the second study, moderate correlations were found between perceptual dimensions and PPD values of the with–anchor group; extra cognitive load was attributed to the inclusion of anchors. Anchors also improved interrater reliability for this listener group. In the third project, again correlation was observed between perceptual ratings and PPD. The inclusion of anchor did not improve reliability over the no-anchor group. Similar to the second study, PPD measures of the with-anchor group were impacted by the use of anchors. 2 Conclusions: Overall, our data offer valuable insights into auditory- perceptual evaluation of voice quality, the influence of listener experience, previous exposure to dysphonic voices, inclusion/exclusion of audio anchors, and voice features and the potential physiological or cognitive responses to dysphonic voices
