Test-Retest Reliability of Relative Fundamental Frequency and Conventional Acoustic, Aerodynamic, and Perceptual Measures in Individuals With Healthy Voices.

Purpose: Recent studies have shown that an acoustic measure, relative fundamental frequency (RFF), has potential for the assessment of excessive laryngeal tension and vocal effort associated with functional and neurological voice disorders. This study presents an analysis of the test-retest reliability of RFF in individuals with healthy voices and a comparison of reliability between RFF and conventional measures of voice. Method: Acoustic and aerodynamic measurements and Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) were performed on 28 individuals with healthy voices on 5 consecutive days. Participants produced RFF stimuli, a sustained /a/, and a reading passage to allow for extraction of acoustic measures and CAPE-V ratings; /pa/ trains were produced to allow for extraction of aerodynamic measures. Results: Moderate reliabilities (intraclass correlation coefficient [ICC] = .64-.71) were found for RFF values. Mean vocal fundamental frequency, smoothed cepstral peak prominence, shimmer, harmonics-to-noise ratio, and mean airflow rate exhibited good-to-excellent reliabilities (ICC = .76-.99). ICCs for jitter and phonation threshold pressure were moderately reliable (ICC = .67-.74). ICCs for subglottal pressure estimates and all CAPE-V parameters showed poor reliabilities (ICC = .31-.58). Conclusion: RFF has comparable reliability to conventional measures of voice. This expands the potential for clinical application of RFF. [ABSTRACT FROM AUTHOR]