Voice disorders in school-age children can have devastating physical, social, and emotional consequences. Vocal nodules are the most commonly diagnosed voice disorder in children and are typically accompanied by vocal hyperfunction: aberrant phonation patterns due to excessive or unbalanced muscular forces. The primary treatment for vocal nodules is voice therapy; however therapy has variable success rates, which is often attributed to a lack of a cohesive, theoretically-based framework specifically for children with voice disorders. One potential reason for the absence of this framework is the lack of knowledge regarding vocal motor development in children with vocal nodules. Although preliminary work in adults with vocal hyperfunction suggests the presence of disordered auditory-motor integration, no studies have yet characterized vocal motor control in children with vocal hyperfunction. As both the vocal mechanism and vocal motor control are known to change across the lifespan, it is important to specifically examine vocal motor control in children with vocal nodules in order to develop a pediatric-specific framework for effective voice therapy. This project will investigate vocal motor control in children with vocal nodules through two specific aims, both based on the theoretical framework of the Directions Into Velocities of Articulators (DIVA) model, a widely used neural network model of speech motor control. Two groups of school-age children (7;0 ? 12;11 years) will participate: one group diagnosed with vocal nodules and the second typically developing age- and sex- matched controls.
Both aims will be addressed using one experimental session. The response to perturbation of fundamental frequency (fo) in children with vocal nodules will be compared to controls.
Aim 1 will determine the ability of participants to update their feedforward vocal motor control system and whether this ability is mediated by auditory acuity. Potential differences in the magnitude or direction of adaptive responses to sustained perturbation of fo will be examined. In addition, the magnitude of those responses will be evaluated in relation to participants? auditory acuity of fo.
Aim 2 will characterize feedback control of fo via analysis of reflexive responses to unexpected perturbations of fo, as well as baseline fo variability. Results from this study will lead to improved understanding of the interaction between vocal motor development and vocal nodules in children, which is essential for further development of pediatric-specific therapies.
This project will investigate the vocal motor control system in children with vocal nodules. Therapies for children with vocal nodules have varied success rates, partially due to lack of a cohesive framework as well as a paucity of understanding about vocal motor development in children with vocal nodules. This proposal will provide crucial information for the advancement of assessment and treatment specificity and effectiveness in children with vocal nodules.
