The Influence of Voice Training on Vocal Learners’ Supraglottal Activities and Aerodynamic Evaluation

Among music majors with only 18 months of training, supraglottal activities and aerodynamic parameters were studied to facilitate understanding of the influence of voice training on characteristics of voice production. Twenty-three students at the Xiamen Music School were examined over the course of 18 months of singing training. Only 17 students completed all data collection sessions. All students had no previous voice training and were confirmed to be without organic voice disorders by a laryngologist but did present with supraglottal compression. Strobolaryngoscopy and aerodynamic assessment were performed every 6 months. Using the laryngoscopic images, anterior-posterior (A-P) compression and medial-lateral compression were analyzed. Aerodynamic assessment was carried out to measure maximum phonation time, phonation threshold flow, glottal resistance, subglottal pressure, phonation threshold pressure, and vocal efficiency. From these measurements, the mean was calculated along with a measurement of reliability. One-way ANOVA with Bonferroni post hoc test was used to evaluate the results between subjects at different time points. Kendall's W test was completed to assure consistency between and within laryngologists. Referring to the Strobolaryngoscopy Evaluation Rating Form, 4 of the 17 students had decreased A-P compression scores in the second measurement compared to the first (from 2.24 ± 0.20 to 2.12 ± 0.17, P = 0.100). After completion of the program, 6 of the 17 students’ anterior-posterior compression scores further improved from the second measurement (from 2.12 ± 0.17 to 1.71 ± 0.17, P = 0.600). The A-P compression scores showed a gradual downward trend and was overall statistically significant (P = 0.004). In addition, there was an improvement of maximum phonation time (P​ ​= 0.016). Professional voice training can improve the supraglottal activities and maximum phonation time. These parameters have potential to be used for voice training evaluation and screening.