The relationship between perception of vocal effort and relative fundamental frequency during voicing offset and onset.

PURPOSE In this study, the authors aimed to determine the relationship between relative fundamental frequency (RFF) and listener perception of vocal effort in individuals with varying degrees of vocal hyperfunction. METHOD Thirty women diagnosed with voice disorders commonly associated with vocal hyperfunction and 10 healthy women provided speech samples that were used to obtain parameters of RFF. Twelve listeners judged the speech samples for overall severity and vocal effort (VE) using rating scales. RESULTS Significant but relatively weak negative correlations were found between perceptual measures and offset RFF parameters. Although offset RFF was increased in healthy participants relative to speakers with voice disorders, no differences were seen in RFF as a function of severity of VE in individuals with voice disorders. CONCLUSIONS Although a statistically significant correlation between offset RFF and VE was found, examination of data as a function of both VE and health status indicated that RFF more accurately classifies the presence of a voice disorder than does severity of voice quality or VE. There is a need for further research to investigate the clinical utility of RFF measures for assessment of rehabilitation progress.