Aerodynamic Study of Velopharyngeal Insufficiency in 22q11.2 Deletion Syndrome

OBJECTIVES

We aim to verify velopharyngeal sphincter function in 22q11.2 deletion syndrome patients (22q11.2DS) to establish correlations between aerodynamic and perceptual measures of nasality, and to identify aerodynamic measures differentiating typical from atypical velopharyngeal behavior.

METHODS

Eleven subjects with 22q11.2DS and twenty similar-age control subjects were recruited. The aerodynamic measures were mean Sound Pressure Level, air pressure peak, pressure wave duration, airflow pattern and nasal airflow during the sequence /pi/. The nasality perceptual measures were rhinolalia, rhinophony and nasal air escape.

RESULTS

Airflow patterns and perceptual measures were statistically different in the two groups. Pressure wave duration and air pressure peak were lower in study subjects than in controls. Air pressure peak and nasal airflow were negatively correlated with rhinolalia; pressure wave duration was negatively correlated with nasal air escape and rhinolalia in 22q11.2DS patients.

CONCLUSIONS

This aerodynamic study identified velopharyngeal qualitative and quantitative dysfunctions, suggesting heterogeneous models of velopharyngeal function in syndromic subjects as compared to controls.

Task-Dependent Velopharyngeal Timing in Singers with Classical Training

OBJECTIVE

This study examined velopharyngeal (VP) timing characteristics during singing and speaking tasks among singers with varying degrees of classical training.

METHODS

Pressure-flow data were collected when eight soprano singers sang and spoke the phrase, "I will say hamper," at different pitch (C4 and C5) and loudness levels (soft, medium, and loud). VP aerodynamic variables (VP gap, peak nasal airflow [NF], and peak intraoral pressure [OP]) and timing variables (NF pulse duration, OP pulse duration, and total duration of the /mp/ sequence) were of particular interest.

RESULTS

Results of linear mixed-effects models showed no significant main effect of task type (speaking vs. singing) on VP aerodynamic variables. Task type was found to have a statistically significant main effect on OP pulse duration (F_{(1, 77)} = 27.590, P < 0.05) and total duration of the /mp/ sequence (F_{(1, 75.034)} = 17.895, P < 0.05), with both durational measures significantly shorter for singing (OP pulse duration: 200 ms, total duration of the /mp/ sequence: 212 ms) than for speaking (OP pulse duration: 228 ms, total duration of the /mp/ sequence: 238 ms). The pitch had a significant main effect on OP pulse duration, with C5 (207 ms) significantly shorter than C4 (221 ms). Loudness was found to have no significant main effects on any of the VP timing variables.

CONCLUSIONS

VP timing patterns significantly differed between the singing and the speaking task. Specifically, the singers employed a quick OP pulse rise time, which shortened OP pulse duration as well as the total duration of the /mp/ sequence during the singing task in comparison to the speaking task. Robust VP timing patterns observed during singing may reflect the singers' skilled control of the VP mechanism to achieve functional and esthetic goals.

Effects of Surgical Intervention and Continuous Positive Airway Pressure Therapy on Velopharyngeal Structure and Function: A Case Report

Changes to the velum and velopharyngeal muscles following Furlow double-opposing Z-plasty in a 7-year-old female with submucous cleft palate and velopharyngeal dysfunction (VPD) were evaluated. Perceptual, instrumental (ie, nasometry and aerodynamic pressure flow), and research magnetic resonance imaging analyses were used during pre- and postsurgical time points at a university research clinic. Continuous positive airway pressure (CPAP) therapy was trialed following a failed surgery for residual VPD in the patient. Increases in velar length and thickness and decreases in levator veli palatini muscle angle of origin and contraction were observed following the Furlow double-opposing Z-plasty surgery. Variable improvements in residual hypernasality following the home-based CPAP therapy protocol were observed.

Nasalization Amplitude-Timing Characteristics of Speakers With and Without Cleft Palate

OBJECTIVES

To examine the amplitude-temporal relationships of acoustic nasalization in speakers with a range of nasality and to determine the extent to which each domain independently predicts the speaker's perceived oral-nasal balance.

DESIGN

Rate-controlled speech samples, consisting of /izinizi/, /azanaza/, and /uzunuzu/, were recorded from 18 participants (14 with repaired cleft palate and 4 without cleft palate) using the Nasometer. The mean nasalance of the entire mid-vowel-nasal consonant-vowel (mid-VNV) sequence (amplitude-domain) and the duration of the nasalized segment of the mid-VNV sequence (temporal-domain) were obtained based on nasalance contours.

RESULTS

Strong linear and vowel-dependent relationships were observed between the 2 domains of nasalization (adjusted R² = 71.5%). Both the amplitude- and temporal-domain measures were found to reliably predict the speaker's perceived oral-nasal balance, with better overall model fit and higher classification accuracy rates observed in /izinizi/ and /uzunuzu/ than in /azanaza/. Despite poor specificity, the temporal-domain measure of /azanaza/ was found to have a strong correlation with the participants' Zoo passage nasalance scores (r_s = .897, p < .01), suggesting its potential utility as a severity indicator of perceived nasality.

CONCLUSIONS

With the use of relatively simple speech tasks and measurements representing the amplitude and temporal domains of nasalization, the present study provided practical guidelines for using the Nasometer in assessing patients with oral-nasal resonance imbalance. Findings suggest that both domain measures of nasalization should be examined across different vowel contexts, given that each domain may provide clinically relevant, yet different, information.