The Reliability of Vocal Intensity and Pitch Range in Unilateral Vocal Fold Palsy Patients
Siti Nurfarhana Mohd Arif;Mawaddah Azman;Sharifa Ezat Wan Puteh; Nur Shahrina Mohd Zawawi;Abdullah Sani1 and Marina Mat Baki.
Journal Title:Acta Scientific Otolaryngology
Objectives:1) to evaluate the reliability of measurements of maximum vocal intensity (maxVI), reading pitch range (RPR) and sing-ing pitch range (SPR); 2) to determine the parameters’ correlation with voice handicap index-10 (VHI-10); and 3) to compare the difference of the parameters between pathology and healthy group.Methods: This cross-sectional studythat was performed in a tertiary centre included 30 patients diagnosed with unilateral vocal fold palsy (UVFP) and 30 healthy volunteers (n = 60 participants). The participants’ voices were measured for maxVI (dB) using Sound Level Meter (SLM) at 100cm, and RPR and SPR (Hertz) using OperaVOX at 30cm distance, from lips. The phonation tasks were vowel /a/ at maximum loudness (maxVI), reading a standard passage (RPR) and glissando mode /a/ (SPR). The measurements were re-peated within 30 minutes interval. Voice handicap index-10 (VHI-10) was documented for all participants. The internal consistency of the measurements was evaluated using intraclass correlation (ICC). Correlation of parameters with VHI-10 was assessed with Spearman Correlation Coefficient. The comparison between two groups was done with Mann Whitney U Test. Results: The reliability of maxVI, RPR and SPR was substantial to excellent with ICC of 0.83 (0.7,0.89), 0.9 (0.94,0.97) and 0.62 (0.44, 0.61) respectively. There was a significant difference for maxVI and SPR between the UVFP and healthy volunteers (p < 0.01). MaxVI showed good significant negative correlation with VHI-10 (r -0.63, p < 0.05) whereas RPR and SPR were poorly correlated with VHI-10 (r = -0.126 and r = -0.28, p > 0.05). Conclusions: MaxVI showed good results depicted by its excellent reliability, ability to differentiate between UVFP and healthy volunteers and good correlation with VHI-10. Thus, MaxVI is may be a potential primary outcome measure in future clinical trials related to UVFP.