Vibratory source, vocal quality and fundamental frequency following pediatric laryngotracheal reconstruction

Surgeons who perform pediatric laryngotracheal reconstruction (LTR) have traditionally measured outcomes based on successful airway restoration. Additional information regarding post-surgical vocal function may help guide outcomes toward optimal voice. This investigation documented the relationship between the site of vocal tract vibratory source (glottic versus supraglottic versus mixed) and vocal function in children following LTR.

Endoscopic evaluation of voice source was completed in 16 participants who had LTR as children. Three judges rated vocal quality using the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V). Acoustic analysis was completed to obtain fundamental frequency and determine the periodicity of the vibratory signal.

Seven participants were identified to have glottic vibration and nine had supraglottic or mixed-source vibration for voice. All participants were rated as having some degree of voice disorder. Those who used primarily supraglottic/mixed phonation exhibited significantly worse overall severity, roughness, and pitch deviance ratings than did those who used primarily glottic phonation. Significant differences in strain were also noted; however, poor inter-rater reliability rating of strain confounded this result. No significant differences in breathiness or loudness ratings were exhibited. Periodic vibration was observed in 10 of 16 participants (5 of 7 in the glottic group and 5 of 9 in the supraglottic/mixed group). Three of the five participants who had periodic supraglottic phonation had fundamental frequency measures (F(0)) that were below normative ranges, 1 approximated normal, and 1 was above normal range. Two of the five participants who had periodic glottic phonation had lower than expected F(0)s, 1 was within normal range, and 2 were high.

As observed in earlier studies, voices produced with supraglottic phonation were generally less acceptable than those with glottic phonation. However, phonation with supraglottic structures yielded highly variable voice that may be amenable to change. Some children achieved periodic vibration with alternate structures, suggesting inherent flexibility and adaptability in the tissues used to make sound.