Acoustic Analysis of the Normal Voice in Classically Trained Vocal Professionals: A Cross-sectional Study

Professional singers are often described as vocal athletes due to the intense vocal demands of their profession, which may lead to functional impairments affecting their quality of life and career. Acoustic analysis provides an objective and quantitative method to assess voice quality. This study aimed to analyze the acoustic and aerodynamic voice characteristics in professional classically trained singers without subjective vocal complaints, as such a sample has been rarely studied.

This cross-sectional study included 88 professional singers, ranging from the early stages to many years of active careers, divided into five groups based on voice type. Acoustic analysis was conducted using the LingWAVES voice protocol. Participants were also examined with flexible fiberoptic laryngoscopy to ensure vocal health before testing.

All participants demonstrated satisfactory results for the s/z ratio, indicating good vocal control. Maximum Phonation Time (MPT) values were lower than normative values in the basses and baritones. The Dysphonia Severity Index (DSI) scores indicated excellent voice quality for all groups. However, shimmer values exceeded normative values in the majority of participants, and higher values of irregularity were also observed in male voices. The bass group revealed unexpectedly high F0 values.

Our results suggest that the current protocol, which relies on speaking voice and sustained phonation tasks, may not reliably assess professional singing voices. Standard normative thresholds may therefore be unsuitable for this population. Future studies should develop adapted protocols with ecologically valid tasks, validate adapted normative values and/or create tools specifically tailored to the acoustic characteristics of classically trained singers.