Effects of Intensive Semioccluded Vocal Tract Therapy on Pediatric Vocal Nodules: A Randomized Controlled Trial

To compare effects of intensive semioccluded vocal tract (iSOVT) therapy and resonant voice therapy (RVT) in 7-12-year-old choir children with bilateral grade 1 or 3 vocal fold nodules.

Forty children were randomized to iSOVT (n = 20) or RVT (n = 20) in a 2×2 design stratified by grade (10 Grade 1, 10 Grade 3 per arm). Both groups received 11 hours of voice therapy over 6 weeks. Acoustic (jitter, shimmer, harmonic-to-noise ratio, cepstral peak prominence [CPP], and fundamental frequency [F0]), aerodynamic (s/z ratio, maximum phonation time [MPT]), perceptual (grade, roughness, breathiness, asthenia, strain [GRBAS] grade), and parent-reported pediatric voice handicap index (pVHI) scores were obtained pre- and post-treatment.

Each therapy produced significant pre-post improvement across acoustic, aerodynamic, and perceptual outcomes (all within-group P ≤ 0.011 for iSOVT; all P = 0.001 for RVT). In both grade 1 and grade 3 iSOVT subgroups, perturbation measures, s/z ratio, GRBAS total, CPP, MPT, and pVHI improved, with CPP gains of about 1-1.5 dB. RVT showed similar changes. Between-group comparisons of change scores showed selective advantages for iSOVT: in grade 1, GRBAS total improved more with iSOVT than RVT (P ≤ 0.05), and in grade 3, F0 decreased more (P ≤ 0.05); other between-group differences were nonsignificant (P ≥ 0.10).

Intensive iSOVT and RVT both yielded substantial gains in pediatric vocal nodules, with iSOVT conferring additional benefits for perceptual dysphonia severity and pitch normalization in grade-stratified analyses.