The Impact of a Vocal Loading Task on Voice Characteristics of Female Speakers With Benign Vocal Fold Lesions.

Abstract

To examine the effect of a vocal loading task on measures of vocal structure and function in females with benign vocal fold lesions (BVFLs) and determine if change is observed in voice and lesion characteristics. Prospective cohort study. Twenty-eight (n=28) female subjects with phonotraumatic BVFLs completed a vocal loading task of 30 minutes of reading aloud at 75-85 dBA. Multidimensional voice evaluation was completed pre- and post-load, including audio and videostroboscopy recordings and images for expert perceptual ratings and acoustic and aerodynamic evaluation. Subjects also scored themselves using a 10 cm visual analogue scale for Perceived Phonatory Effort, and completed the Evaluation of Ability to Voice Easily, a 12 item self-report scale of current perceived speaking voice function. An exploratory rather than confirmatory approach to data analysis was adopted. The direction and magnitude of the change scores (pre- to post-load) for each individual, across a wide variety of instrumental and self-report measures, were assessed against a Minimal Clinically Important Difference criteria. Observations of change and the direction of change in vocal response of individuals with BVFLs to 30 minutes of loud vocal load was variable. Minimal to no change was noted for participants pre- to post-load as rated perceptually, for auditory and videostroboscopy samples. For most instrumental measures, change was shown for many participants including an overall improvement in aerodynamic and acoustic measures of function and efficiency post-load for 20 participants (77%) and decline in function for 4 participants (15%). Self-reported effort and vocal function post-load was multidirectional with similar numbers of participants reporting no change, improved function or a decline. Subjects with BVFLs demonstrate change in vocal function following 30 minutes of vocal load. While this change can be variable and multidirectional, overall improvement was observed in instrumental measures of function and efficiency for most participants. Some participants perceived this change to be an increase in effort, some a reduction in effort and some perceived no change. Improved vocal function despite relative lesion stability can seemingly occur after loading in some pathological voices.