Background:
The main goal of voice therapy in children with vocal fold nodules is to improve their communication, vocal quality and wellbeing. However, in this population, efficacy or effectiveness studies of voice therapy are extremely limited and show methodological shortcomings. There is an urgent need to understand the impact of different semi-occluded vocal tract (SOVT) techniques on the multidimensional facets of voice, as these SOVT exercises are frequently used in clinical practice. The common feature of these exercises is a reduction in the cross-sectional area of the vocal tract while voicing. Results of this project will have an impact on evidence-based voice therapy in children and consequently on reimbursement agreements of the health care system in the future. This fundamental research regarding the impact of SOVT techniques on the voice can also lead to the development and improvement of SOVT techniques.
Purposes:
* The first purpose of this project is to determine and compare the short-term effect of a "non-intuitive" SOVT therapy program (straw phonation) with a more traditional "intuitive" resonant voice therapy program of one week on (a) the vocal quality, (b) the laryngeal anatomy and function, and (c) the psychosocial wellbeing in children (aged between 6 and 12 years) with vocal fold nodules using a randomized sham-controlled trial.
* The second purpose of this project is to determine and compare the long-term effect of these voice therapy programs on (a) the vocal quality, (b) the laryngeal anatomy and function, and (c) the psychosocial wellbeing of the children.
Hypotheses:
Giving the promising physics of an SOVT, a positive short-term effect of straw phonation and resonant voice therapy is hypothesized. However, the non-intuitive technique straw phonation is expected to be in favor for a pediatric population. For these exercises, semi-occlusions are created by an external tool and instructions, feedback, and self-corrections can be reduced to a minimum. These factors might lead to faster results, which might in turn reduce feelings of frustration and demotivation by the children.
Study design:
A longitudinal randomized sham-controlled trial will be used. Patients will be randomly assigned to one of the 2 treatment groups "straw phonation", "resonant voice therapy", or the control group receiving a "sham treatment".
Innovativity:
This research will be innovative because of (a) the topic and study population (SOVT in children between 6 and 12 years) which is an underexposed domain in literature; (b) the methods investigating multidimensional facets of voice (c) the randomized sham-controlled study design using a large study group, a control group receiving sham treatment, random allocation of participants and blinded assessors and (d) the combination of short-term and long-term outcome.
Participants:
Inclusion criteria and exclusion criteria are described further in the application.
Voice assessment:
A standardized and multidimensional voice assessment including both objective and subjective vocal outcomes will be performed to evaluate the participants' voice pre and post-therapy, and at 3 months and 6 months follow-up. The multidimensional voice assessment will consist of the following outcomes: (a) vocal quality, (b) laryngeal anatomy and function, and c) psychosocial wellbeing. Assessments (a) and (c) will be performed in a sound-treated room at Ghent University Hospital by speech-language pathologists experienced in voice diagnostics. Assessments (b) will be performed by experienced otorhinolaryngologist. All assessors will be blinded to group allocation and study evolution. A detailed overview of the outcome characteristics is described further in the application.
Voice therapy:
The content of the different therapy arms / interventions is described further in the application.
Statistical analysis:
Linear mixed model analyses (LMM) will be used to determine whether there is a difference in evolution between the groups over time. Post-hoc pairwise comparisons with Bonferroni corrections will uncover specific within and between group differences. Intraclass correlation coefficients models and Cohen's κ will be used to determine inter- ant intrarater reliability.
