Comprehensive Index of Vocal Fatigue (CIVF): Development and Clinical Validation

Abstract

Objectives: In this study, we sought to investigate whether auditory-perceptual and acoustic measures change after a passage-reading task and to develop a multidimensional index of performance fatigue in voice disorders. The clinical usefulness and cut-off scores of the newly developed index were also explored.

Methods: A total of 150 patients (age = 35.65 ± 11.44 years) with voice disorders and 100 healthy controls (age = 35.04 ± 11.26 years) were enrolled in the study. Overall severity (OS) and acoustic measures of sentence samples were obtained before and after a passage-reading task and compared between the two positions. Acoustic features included cepstral peak prominence (CPP), σCPP, L/H spectral ratio (SR), and σSR. Using the changes (Δ) in those acoustic measures and the scores of the Vocal Fatigue Index (VFI), a predictive model of the ΔOS was established. The clinical cut-off point of the index was also identified.

Results: For the patient group, OS was higher, but CPP and σCPP were lower for the rear position (after reading the passage) compared to the front position (before reading the passage). A significant portion (adjusted R2 = 77.7%) of the ΔOS was predicted by ΔCPP, tiredness score of the VFI, ΔσCPP, ΔσSR, and ΔSR. The area under the curve of the newly developed index was .864 (sensitivity, 78.67%; specificity, 78.00%), and the index's criterion was >2.6489.

Conclusions: The newly developed Comprehensive Index of Vocal Fatigue (CIVF) can quantify vocal fatigue in voice disorders, reflecting both acoustic and auditory perceptual changes after a passage-reading task. Further studies should explore the responsiveness of the CIVF and the impact of related factors on the CIVF in various voice disorders.