Immediate Lip Trill Effects on the Standard Diagnostic Measures Voice Range Profile, Jitter, Maximum Phonation Time, and Dysphonia Severity Index

Abstract

Semi-occluded vocal tract exercises are widely applied to improve vocal performance in speakers, singers, and voice patients. This study investigates immediate lip trill effects on standard voice assessment measures including voice range profiles, jitter, maximum phonation time, and Dysphonia Severity Index in vocally healthy women. Experimental study. Otolaryngology clinic within tertiary hospital. Twenty-five vocally healthy women between 19 and 58 years (mean 38.4) were assessed before and after 3 minutes of standardized lip trill training combined with defined voice fundamental frequency and intensity modulations. Main outcome measures were fundamental frequency (F0) during counting (F0 counting), the singing voice range profile parameters minimum, maximum and range of F0 and voice sound pressure level (voice SPL), jitter (%), maximum phonation time (MPT), and the Dysphonia Severity Index (DSI). Wilcoxon signed rank test was applied to determine significant changes after exercise. After exercise the singing F0 and SPL range significantly increased from 549 (SD 217) to 612 (238) Hz and 45.1 (10.1) to 47.3 (9.8) dBA, resepctively (P<0.05). Maximum voice SPL significantly increased from 90.9 (10.3) to 94 (9.7) dBA (P<0.05). Mean F0 during counting showed a highly significant increase from 198 (SD 25.6) to 209 Hz (SD 25.4, P<0.01). No significant changes were found for all other parameters. In vocally healthy women, lip trill training immediately facilitates increases in mean F0 during counting, and singing F0 and SPL range. Future studies should investigate, if changes to these parameters indicate immediate responsiveness to voice exercise also in voice patients, and if these findings transfer to long-term effects through prolonged training.