Outcome of laryngeal and velopharyngeal biofeedback treatment in children and young adults: A pilot study

A relatively new management strategy for the treatment of voice disorders is the use of laryngeal (LB) and velopharyngeal biofeedback (VB). The main purpose of the present pilot study is to document the outcome of vocal and velopharyngeal performances after a well-defined LB and VB treatment. Four subjects were studied pretreatment (1 week before LB or VB treatment) and posttreatment (1 week after the LB or VB treatment). To measure and compare the effect of LB and VB, objective and subjective assessment techniques were used. Perceptual voice assessment included a perceptual rating of the voice using the GRBAS scale. Furthermore, the vocal quality in this population is modeled by means of the Dysphonia Severity Index. For the objective assessment of nasal resonance, the Nasometer and the Glatzel test were used. A perceptual evaluation of speech, the Gutzmann test, and the tests from Bzoch were used as subjective assessment techniques. Both patients selected for LB and VB treatment showed improvement of their performances. The resulting improvement, as measured by means of an objective approach, is in agreement with the perceived (auditory) improvement of voice and resonance. The use of LB and VB treatment in patients, especially in some subjects who are not responding to traditional voice or velopharyngeal therapy, must be encouraged.     

The role of knowledge of results in performance and learning of a voice motor task

The relationship between the provision of Knowledge of Results and the performance and learning of a voice motor task was examined. Thirty adult subjects, randomly assigned to a 100%, 50%, or No Knowledge of Results group, practiced a novel vowel nasalization task. Measures of accuracy and variability obtained during the practice session indicated influence of knowledge of results schedule on the transient effects of motor performance. Deviations from the nasalance target during the retention phase, 5 minutes later, and during a transfer phase, 24 hours later, indicated influence of knowledge of results schedule on the permanent effects of motor learning. Collective results revealed that an increase in relative frequency of knowledge of results led to a decrease in motor performance and learning of a vowel nasalization task: Both accuracy and variability were degraded as knowledge of results increased, with those subjects in the 100% group exhibiting the poorest scores.     

The Effects of Frequency Range, Vowel, Dynamic Loudness Level, and Gender on Nasalance in Amateur and Classically Trained Singers

This study addresses two questions: (1) How much nasality is present in classical Western singing? (2) What are the effects of frequency range, vowel, dynamic level, and gender on nasality in amateur and classically trained singers? The Nasometer II 6400 by KayPENTAX (Lincoln Park, NJ) was used to obtain nasalance values from 21 amateur singers and 25 classically trained singers while singing an ascending five-tone scalar passage in low, mid, and high frequency ranges. Each subject sang the scalar passage at both piano and mezzo-forte dynamic loudness levels on each of the five cardinal vowels (/a/, /e/, /i/, /o/, /u/). A repeated mixed-model analysis indicated a significant main effect for the amateur/classically trained distinction, dynamic loudness level, and vowel, but not for frequency range or gender. The amateur singers had significantly higher nasalance scores than classically trained singers in all ranges and on all vowels except /o/. Dynamic loudness level had a significant effect on nasalance for all subject groups except for female majors in the mid- and high-frequency ranges. The vowel, /i/, received significantly higher nasalance than all of the other vowels. Although results of this study show that dynamic loudness level, vowel, and level of training in classical singing have a significant effect on nasality, nasalance scores for most subjects were relatively low. Only six of the subjects, all of whom were amateur singers, had average nasalance scores that could be considered hypernasal (ie, a nasalance average of 22 or above).     

The effect of uvulopalatopharyngoplasty on the nasality of voice

We prospectively studied the effect of uvulopalatopharyngoplasty (UPPP) on several speech and vocal parameters in 15 patients. Preoperative, 1-month postoperative, and 6-month postoperative assessments were made. Specific parameters included maximum phonation time, mean speaking fundamental frequency, mean frequency perturbation, intensity, and nasalance. Psychoacoustic analysis included pitch, quality, rate, resonance, and loudness. The primary outcome measure was the nasality of voice. At the 1-month postoperative assessment, one patient exhibited mild hypernasality by psychoacoustic analysis and a mildly elevated measured nasalance. At 6 months, both the psychoacoustic hypernasality and the measure nasalance had normalized. Consequently, no subjects exhibited hypernasality at the final assessment. Although abnormalities by psychoacoustic analysis were exhibited by 3 subjects at the 6-month postoperative assessment, none could be attributed to the surgery, but rather to concurrent illnesses. This study adds further data and support that UPPP done in standard fashion does not result in significant changes in voice either by measured parameters or by clinical assessment. Although this study does not obviate the need for preoperative counseling of patients about the potential effect of UPPP on voice, they can be counseled that the risk of hypernasality after UPPP is low.