Objective dysphonia quantification in vocal fold paralysis: comparing nonlinear with classical measures.

Clinical acoustic voice-recording analysis is usually performed using classical perturbation measures, including jitter, shimmer, and noise-to-harmonic ratios (NHRs). However, restrictive mathematical limitations of these measures prevent analysis for severely dysphonic voices. Previous studies of alternative nonlinear random measures addressed wide varieties of vocal pathologies. Here, we analyze a single vocal pathology cohort, testing the performance of these alternative measures alongside classical measures. We present voice analysis pre- and postoperatively in 17 patients with unilateral vocal fold paralysis (UVFP). The patients underwent standard medialization thyroplasty surgery, and the voices were analyzed using jitter, shimmer, NHR, nonlinear recurrence period density entropy (RPDE), detrended fluctuation analysis (DFA), and correlation dimension. In addition, we similarly analyzed 11 healthy controls. Systematizing the preanalysis editing of the recordings, we found that the novel measures were more stable and, hence, reliable than the classical measures on healthy controls. RPDE and jitter are sensitive to improvements pre- to postoperation. Shimmer, NHR, and DFA showed no significant change (P>0.05). All measures detect statistically significant and clinically important differences between controls and patients, both treated and untreated (P<0.001, area under curve [AUC]>0.7). Pre- to postoperation grade, roughness, breathiness, asthenia, and strain (GRBAS) ratings show statistically significant and clinically important improvement in overall dysphonia grade (G) (AUC=0.946, P<0.001). Recalculating AUCs from other study data, we compare these results in terms of clinical importance. We conclude that, when preanalysis editing is systematized, nonlinear random measures may be useful for monitoring UVFP-treatment effectiveness, and there may be applications to other forms of dysphonia.

Long-term quantitative results of an Isshiki type 4 thyroplasty-a case study.

OBJECTIVE: We believe that we have described the first instance of long-term follow-up of a bilateral Isshiki type IV thyroplasty in a 58-year-old woman after bilateral superior laryngeal nerve (SLN) damage. METHOD: Comparison of voice handicap index-10 (VHI-10) questionnaire and electrolaryngographic measurements pre- and post-thyroplasty (type IV). RESULTS: VHI-10 scores reduced from 25 pre-thyroplasty to seven and five at 6 and 34 months, respectively. Mean, mode, and median dynamic frequency range (DFx-1) scores increased from 118, 125, and 124 Hz preoperatively to 144, 172, and 163 Hz at 6 months and 167, 167, and 169 Hz, at 34 months, respectively (a subjectively higher voice). Range of tones produced while speaking reduced from an 80% range of 2.48 octaves and 90% range of 3.52 octaves to scores of 1.46 and 2.75 octaves for 80% and 90%, respectively at 6 months and 0.82 and 1.73 octaves at 34 months (a more defined voice). Ninety percent spectrum of single tone production increased from 0.17 octaves preoperatively to 0.55 octaves at 6 months and 0.49 octaves at 34 months. DISCUSSION: Type IV thyroplasty is most commonly performed for the male-to-female transsexual patient. Bilateral SLN palsy can be effectively treated with this approach with good long-term results. CONCLUSION: Three-year follow-up for bilateral type IV thyroplasty reveals increased pitch, definition, and clarity but decreased range overall.

"Hot potato voice" in peritonsillitis: a misnomer.

The "hot potato voice" is widely recognized as a symptom of peritonsillar cellulitis or abscess; yet there have been no studies assessing the resonance characteristics of the vocal tract in peritonsillitis. Analysis was undertaken of formant frequencies in the articulation of the vowels /i:/. /a:/ and /u:/ in six subjects with peritonsillitis and compared with articulation once the peritonsillitis had settled. Significant variation was found in F1 when articulating /i:/ and in F2 when articulating /a:/, which are explainable by dyskinesis of the peritonsillar musculature. These findings were compared with six subjects articulating the same vowels with and without a hot potato in their mouth. Variation was found in both F1 and F2 when articulating /i:/, which can be related to interference of the potato with movement of the anterior tongue. The changes in the vocal tract differ in these two cases and the title "hot potato voice" in peritonsillitis is a misnomer.