Velopharyngeal port status during classical singing

Nasalance, Nasal Airflow and Perceived Nasality in Carnatic Singers and Non-singers

This study aims to compare the nasalance and nasal airflow between professional singers trained in Carnatic classical singing and non-singers. We also aimed to correlate perceived nasality with objective measurements of nasalance and nasal airflow. A total of 40 female participants (20 to 50 years) were involved in this study. The first group comprised 15 female professional Carnatic singers with a minimum of 10 years of classical training. The second group consisted of 25 non-singer females. These participants were compared on nasalance, nasal airflow and perceived nasality across three sets of stimuli (vowels, oral non-words, and nasal non-words) and three pitch-conditions (low, mid, and high). Correlations were also made between objective measures of nasalance and nasal airflow and perceived nasality. Mixed ANOVA showed a significant (P < 0.05) interaction in nasalance between pitch conditions and groups. Group differences were also observed in the nasalance scores of vowels, oral non-words, nasal non-words. There was a significant difference (P < 0.05) in nasalance with ascending pitch in singers and non-singers. A comparison of aerodynamic analysis of vowels, oral non-words, and nasal non-words between singers and non-singers suggested that nasal airflow was higher in singers. Perceptual nasality was significantly lower (P < 0.05) in Carnatic singers than non-singers. Correlations between objective measures of nasalance and nasal airflow and perceived nasality were not observed. Despite an increased airflow, nasality was lower in trained Carnatic singers than non-singers. Current findings suggest that vocal training impacts nasalance, nasal airflow and perceived nasality.

The Role of Instructions in Motor Learning of Oral Versus Nasalized Speech Targets

PURPOSE

The purpose of this study was to investigate how general, implicit instructions with auditory-perceptual emphasis; specific, explicit instructions with biomechanical focus; or both affect learning of oral-nasal balance control in speech.

METHOD

Thirty healthy, vocally untrained participants were assigned to one of three instructional groups (i.e., implicit, explicit, and integrated) and learned to produce oral versus nasalized vowel-, syllable-, and phrase-level targets during once-weekly sessions over 4 weeks. Learning gains and performance variability were analyzed using nasometry.

RESULTS

We observed a significant main effect of instruction type on learning gains at phrase level (p = .016). Specifically, the integrated group (M = 59.8%) significantly outperformed the explicit group (M = 37.9%) and numerically outperformed the implicit group (M = 45.1%). For nasalized phrase targets, results revealed a significant main effect of instruction type on performance variability (p = .042), but pairwise comparisons between instruction groups were not significant.

CONCLUSIONS

The integration of implicit processes via auditory-perceptual modeling and explicit processes via relevant biomechanical directives resulted in larger motor learning gains, especially at higher levels of task complexity (i.e., phrase) compared to providing implicit or explicit instruction alone. The higher performance variability (i.e., less stable productions) that was sometimes induced by explicit instruction did not negatively impact learning when integrated with implicit instruction. Clinical implications for speech/voice therapy models are discussed.

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.

Finite element modeling of the effects of velopharyngeal opening on vocal tract reactance in female voice

Classical singers use nasal consonants as "resonance exercises," and experimental results have shown that singers may use some velopharyngeal opening (VPO), most often in [a:] and more seldom in [i:] or [u:]. In particular, male singers have been found to increase VPO as pitch rises toward register change frequencies (passaggi). Laryngoscopic findings have shown that some VPO stabilizes vocal fold vibration; the effect is related to positive reactance. This study investigates the effects of VPO on vocal tract (VT) reactance over the range of fundamental frequencies (f₀) used in singing using a computerized tomography-based finite element model of the VT and nose of a female. According to the results, by raising the lowest VT resonances, the VPO increased the VT reactance in the frequency ranges 207-359 Hz for [i:], 265-411 Hz for [u:], and 500-611 Hz for [a:], depending on the VPO size (full or half VPO). These frequency ranges are close to the first and second passaggio of a female singer. The change may have an especially practical stabilizing effect for [a:], which is otherwise characterized by very large changes in VT reactance and negative reactance at the second passaggio.

Influence of nasal cavities on voice quality: Computer simulations and experiments

Nasal cavities are known to introduce antiresonances (dips) in the sound spectrum reducing the acoustic power of the voice. In this study, a three-dimensional (3D) finite element (FE) model of the vocal tract (VT) of one female subject was created for vowels [a:] and [i:] without and with a detailed model of nasal cavities based on CT (Computer Tomography) images. The 3D FE models were then used for analyzing the resonances, antiresonances and the acoustic pressure response spectra of the VT. The computed results were compared with the measurements of a VT model for the vowel [a:], obtained from the FE model by 3D printing. The nasality affects mainly the lowest formant frequency and decreases its peak level. The results confirm the main effect of nasalization, i.e., that sound pressure level decreases in the frequency region of the formants F₁-F₂ and emphasizes the frequency region of the formants F₃-F₅ around the singer's formant cluster. Additionally, many internal local resonances in the nasal and paranasal cavities were found in the 3D FE model. Their effect on the acoustic output was found to be minimal, but accelerometer measurements on the walls of the 3D-printed model suggested they could contribute to structure vibrations.

Immediate effects of voice focus adjustments on hypernasal speakers' nasalance scores

OBJECTIVES

To explore the immediate effects of voice focus adjustments on the oral-nasal balance of hypernasal speakers, measured with nasalance scores.

METHODS

Five hypernasal speakers (2 M, 3 F) aged 5-12 (SD 2.7) learned to speak with extreme forward and backward voice focus. Speakers repeated oral, nasal, and phonetically balanced stimuli. Nasalance scores were collected with the Nasometer 6450.

RESULTS

From the average baseline of 34.27% for the oral stimulus, nasalance increased to 46.07% in forward and decreased to 30.2% in backward focus. From the average baseline of 64.53% for the nasal stimulus, nasalance decreased to 64.13% in forward and decreased to 51.73% in backward focus. From the average baseline of 51.33% for the phonetically balanced stimulus, nasalance increased to 58.87% in forward and decreased to 46.2% in backward focus.

CONCLUSIONS

Forward voice focus resulted in higher and backward voice focus resulted in lower nasalance scores during speech for a group of hypernasal speakers. However, there was an exception: One male speaker showed decreased nasalance in forward voice focus. Future research should investigate the longer-term effectiveness of the intervention.

Spectrum Effects of a Velopharyngeal Opening in Singing

The question whether or not a velopharyngeal opening is advantageous in singing has been discussed for a very long time among teachers of singing. The present investigation analyzes the acoustic consequences of a large, a narrow, and a nonexistent velopharyngeal opening (VPO). A divided flow mask (nasal and oral) connected to flow transducers recorded the nasal and oral DC flows in four female and four male classically trained singers while they sang vowel sequences at different pitches under these three experimental conditions. Acoustic effects were analyzed in three long-term average spectra parameters: (i) the sound level at the fundamental frequency, (ii) the level of the highest peak below 1 kHz, and (iii) the level of the highest peak in the 2-4 kHz region. For a narrow VPO, an increase in the level of the highest peak in the 2-4 kHz region was observed. As this peak is an essential voice component in the classical singing tradition, a narrow VPO seems beneficial in this type of singing.

Comparison of Fundamental Frequency Nasalance between Trained Singers and Nonsingers for Sung Vowels

Objectives:

The purpose of this study was to determine the effect of vocal training on fundamental frequency nasalance measures under selected vowel and frequency conditions.

Methods:

Fundamental frequency nasalance measures were reported for 2 groups of women: 36 trained singers and 36 nonsingers. Each group sang and sustained the vowels (/i/, /æ/, /u/, /a/) for 6 seconds' duration at 3 frequency levels. A 3-second segment from the middle of each vowel was measured to generate fundamental frequency nasalance scores.

Results:

No significant differences were found in the mean fundamental frequency nasalance scores between the trained singers and the nonsingers. The fundamental frequency nasalance scores were significantly higher for front vowels for both groups. Additionally, both groups displayed a pattern of producing significantly higher fundamental frequency nasalance scores at lower fundamental frequencies than at higher fundamental frequencies.

Conclusions:

These findings support the practice of training singers to elevate the velum when singing at high frequencies but not when singing at low ones.

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).