Glottal Stop Production in Controls and Patients With Unilateral Vocal Fold Paresis/Paralysis

Purposes: The purposes of this study were to determine whether the acoustic measures from glottal stops distinguished between controls and patients with unilateral vocal fold paresis/paralysis (UVFP) at initial evaluation and posttreatment/observation, to explore the types of false vocal fold (FVF) movement during glottal stop production in UVFP, and to assess the agreement between normalization of various measures and reported voice normalization. Method: Patients with UVFP and controls were recorded acoustically and laryngoscopically speaking two sets of five repeated /i/s, controls once and patients with UVFP initially and posttreatment/observation. Averaged intensity differences and slopes for offsets (maximum voicing intensity to minimum glottal stop intensity) and onsets (minimum glottal stop intensity to maximum voicing intensity) were measured. FVF movements were rated separately for paretic and nonparetic sides. Patients were asked to report voice normalization posttreatment/observation. Cohen's kappas were calculated for agreements between patient-reported voice normalization and normalization of Voice-Related Quality of Life (V-RQOL), translaryngeal flow, four acoustic measures of glottal stop production, and FVF movement. Results: Significant differences (analysis of variance [ANOVA]; p < .014) were found for all acoustic measures between controls and patients with UVFP and between patients with UVFP initially and posttreatment/observation (paired t tests; p < .05). In addition, 78% of UVFP patients had no FVF movement on the paretic side initially, and 42% had bilateral dynamic FVF movement posttreatment/observation. Cohen's kappa showed moderate agreement between voice normalization and V-RQOL, slight agreement with offset measures, and fair agreement with onset measures. Conclusion: This study provided proof of concept for using acoustic measures of glottal stops to distinguish between controls and patients with UVFP, both initially and posttreatment/observation.