Validity of the Nasometer Measuring the Temporal Characteristics of Nasalization

The effect of functional endoscopic sinus surgery on nasal resonance

Background and objective

Functional endoscopic sinus surgery (FESS) increases the nasal volume, and thereby it can alter the nasal resonance. The objectives were to measure the percentage of nasal resonance following FESS and compare it with healthy individuals with normal nasal findings.

Methods

The nasometric analysis of voice was done using n/p/m consonant sounds in 72 individuals with healthy post FESS cavities (group 1) and 72 healthy individuals with normal nasal findings without any nasal pathology (group 2). The scores of nasal resonances were expressed in percentages and were compared between the two groups. Both in group 1 and group 2, 32 (44.4%) were females, and 40(55.6%) were males. In group 1, 51 participants had bilateral FESS cavities, and 21 had unilateral FESS cavities. Kannada was the mother tongue in 30 (41.7%) participants in group 1 and 36 (50.0%) in group 2. Malayalam was the mother tongue in 42(58.3%) participants in group 1 and 36 (50.0%) in group 2.

Results

In both cases and control groups, more than 80% of the participants were showing less than 20% of nasal resonance. In group 1, the mean values of/n/p/m sounds were 11.23%, 10.23% and 11.42% respectively, and in group 2 the mean values were 8.27%, 8.58% and 8.58% respectively. But the P value was not statistically significant. Individuals with unilateral FESS cavities had more nasal resonance values compared to bilateral FESS cavities. Similarly, Kannada speaking people had more values compared to Malayam speaking individua.

Conclusion

Changes in nasal resonance after FESS is minimal, and it is unnoticed. But it may affect the speech quality in professional voice users, depending on their language. Though the nasometer is considered as the most validated instrument to record nasal resonance, we feel that further standardization is needed to evaluate the nasalance.

Comparing the Temporal Aspects of Velopharyngeal Closure in Children with and without Cleft Palate

INTRODUCTION

Children with cleft palate exhibit differences in the 4 temporal components of nasalization (nasal onset and offset intervals, nasal consonant duration, and total speech duration), with various patterns having been noted based on different languages. Thus, the current study aimed to examine the temporal aspects of velopharyngeal closure in children with and without cleft palate; this is the first study to do so in the Turkish language.

METHODS

This study evaluated and compared the 4 temporal characteristics of velopharyngeal closure in children (aged 6-10 years) with (n = 28) and without (n = 28) cleft palate using nonword consonant and vowel speech samples, including the bilabial nasal-to-stop combination /mp/ and the velar nasal-to-stop combination /ηk/. Acoustic data were recorded using a nasometer, after which acoustic waveforms were examined to determine the 4 temporal components of nasalization. Flexible nasoendoscopy was then used to evaluate velopharyngeal closure patterns.

RESULTS

With regard to the 4 closure patterns, significant differences in the nasal offset interval (F4-25 = 10.213, p = 0.04; p < 0.05) and the nasal consonant duration ratio (F4-25 = 12.987, p = 0.02; p < 0.05) were observed for only /ampa/. The coronal closure pattern showed the longest closure duration (0.74 s). Children with cleft palate showed prolonged temporal parameters in all 4 characteristics, reflecting oral-nasal resonance imbalances. In particular, the low vowel sound /a/ was significantly more prolonged than the high vowel sounds /i/ and /u/.

CONCLUSIONS

The examined temporal parameters offer more accurate characterizations of velopharygeal closure, thereby allowing more accurate clinical assessments and more appropriate treatment procedures. Children with cleft palate showed longer nasalization durations compared to those without the same. Thus, the degree of hypernasality in children with cleft palate may affect the temporal aspects of nasalization.

Differences in nasalance and nasality perception between Texas South and Midland dialects

While previous research has primarily concerned the dialectal influence on speakers' production of oral-nasal balance, quantitatively represented by nasalance, information on cross-dialectal variation in nasality perception is limited. This study investigated the effects of speakers'/listeners' dialectal background on oral-nasal balance characteristics estimated by nasalance, as well as nasality perception measured by direct magnitude estimation with modulus. Represented by two geographically distinct regions, Texas South and Midland dialects were of special interest given that the two dialects lie at opposite ends of normal nasalance variation [Awan, Bressmann, Poburka, Roy, Sharp, and Watts. (2015). J. Speech Lang. Hear. Res. 58, 69-77]. Mean nasalance of various speech stimuli and direct magnitude estimation ratings on synthesized vowel stimuli with varying degrees of simulated nasalization were obtained from 62 participants (31 Texas South, 31 Midland). The results revealed that the two dialectal groups significantly differed in nasalance scores and nasality ratings, with Texas South exhibiting higher nasalance for standardized passage readings and assigning higher nasality ratings on the synthetic auditory stimuli than Midland. These findings indicate that, in addition to production variations of oral-nasal balance characteristics, perceptual variations of nasality exist at a dialectal level.

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.

Temporal characteristics of nasalization in Persian speaker children with and without cleft palate

OBJECTIVES

The purpose of this study was to measure and compare temporal patterns of nasalization in Persian children with and without cleft palate in three vowel contexts.

METHODS

A Sample of 14 children with repaired cleft palates with or without cleft lip with moderate to severe hyper nasality and 14 children without cleft palate was chosen as subjects. The subjects were chosen from the ages of 4 to 12 years. The nasal onset interval, nasal offset interval and total nasalization duration were obtained from acoustic waveforms and spectrograms in three vowel contexts using Praat Software. For eliminating the effect of different speed of speech in the cleft palate group and control group, the ratio of nasalization duration was calculated.

RESULTS

Total nasalization duration are demonstrated by acoustic signals which shows the total significant different temporal patterns in children with cleft palate and without cleft palate and across the vowel contexts (P<0.000).

CONCLUSIONS

Longer nasalization durations in children with cleft palate in comparison to children without cleft palate show the delayed or deviant temporal patterns in children with cleft palate. The duration of nasalization reflecting temporal patterns of the oral-nasal acoustic impedance in children with cleft palate may have an influence on the perception of hyper nasality.

Avaliação da nasalidade de fala na fissura labiopalatina

Objetivo Descrever os resultados da nasalidade de fala de indivíduos com fissura labiopalatina e comparar os achados de nasalidade estabelecidos por meio do julgamento perceptivo-auditivo realizado ao vivo com os achados estabelecidos por análise de gravações por juízes, em dois tipos de amostras de fala. Métodos O estudo envolveu a análise retrospectiva dos resultados de avaliações perceptivo-auditivas da nasalidade de fala realizadas ao vivo por uma fonoaudióloga e o julgamento prospectivo, por consenso de juízas de 100 gravações de amostras de fala, obtidas durante a produção de dois conjuntos de estímulos de fala: um com consoantes de alta pressão (CAP, n=100) e outro com consoantes de baixa pressão (CBP, n=100). Os dados pertenciam a pacientes de ambos os gêneros, com idades entre 5 e 12 anos, que tiveram a fissura labiopalatina operada por um mesmo cirurgião. Resultados A ausência de hipernasalidade foi constatada em 69% dos julgamentos ao vivo. Quando presente, a hipernasalidade leve foi constatada em 23% dos casos, enquanto a hipernasalidade moderada em 8%. Para os julgamentos das amostras gravadas, 50% foram identificadas com hipernasalidade durante a produção das amostras CAP e 62% durante a das amostras CBP. Diferença significativa foi encontrada entre o resultado do julgamento ao vivo e o julgamento pelas juízas nas amostras CAP. A concordância entre as modalidades de avaliação variou de 79% para as amostras CAP e 80% para as amostras CBP, sendo considerada moderada. Conclusão O julgamento perceptivo ao vivo da nasalidade de fala pode detectar melhor a ausência de hipernasalidade, seguida pela hipernasalidade de grau leve, em comparação com o julgamento realizado por juízes múltiplos, a partir de amostras gravadas. Contudo, tem a desvantagem de os dados não poderem ser reproduzidos, nem quantificados, nem compartilhados por outros membros da equipe.

Nasalance during use of pharyngeal and glottal place of production

Purpose:This study obtained nasalance scores during use of compensatory articulation (CA) and compared nasalance between groups with and without hypernasality and with and without CA.Methods:Speech samples were obtained from 43 individuals with and without velopharyngeal dysfunction during repetition of 20 phrases originating 860 audio recordings and their respective nasometric values. After excluding 143 recordings due to low quality, the remaining 717 samples were rated by three speech language pathologists (SLPs), independently, for presence or absence of hypernasality and CA. Nasalance scores for the 553 samples rated with 100% agreement among the SLPs were grouped according to the auditory-perceptual ratings: Group 1 (G1) - included samples without hypernasality and without CA (n=191); Group2 (G2) - included samples with hypernasality and without CA (n=288); Group 3 (G3) - included samples with hypernasality and with pharyngeal fricative (n=33); Group 4 (G4) - included samples with hypernasality and with glottal stop (n=41).Results:Analysis of variance (ANOVA) revealed significant difference nasalance scores which were significantly higher for G2, G3, and G4 (p<0.0001) when compared to G1. The use of pharyngeal fricative (G3), particularly during /f/ (p=0.0018) and /s/ (p=0.0017) productions resulted in nasalance scores significantly higher than scores found for G2.Conclusion:Significantly higher nasalance values where identified during use of pharyngeal fricative.

Comparison of nasal acceleration and nasalance across vowels

PURPOSE

The purpose of this study was to determine the performance of normalized nasal acceleration (NNA) relative to nasalance as estimates of nasalized versus nonnasalized vowel and sentence productions.

METHOD

Participants were 18 healthy speakers of American English. NNA was measured using a custom sensor, and nasalance was measured using the KayPentax Nasometer II. Speech stimuli consisted of CVC syllables with the vowels (//, /æ/, /i/, /u/) and sentences loaded with high front, high back, low front, and low back vowels in both nasal and nonnasal contexts.

RESULTS

NNA showed a small but significant effect of the vowel produced during syllable stimuli but no significant effect of vowel loading during sentence stimuli. Nasalance was significantly affected by the vowel being produced during both syllables and sentences with large effect sizes. Both NNA and nasalance were highly sensitive and specific to nasalization.

CONCLUSIONS

NNA was less affected by vowel than nasalance. Discrimination of nasal versus nonnasal stimuli using NNA and nasalance was comparable, suggesting potential for use of NNA for biofeedback applications. Future work to improve calibration of NNA is needed to lower intersubject variability.

Spectral findings for vowels [a] and [ã] at different velopharyngeal openings

BACKGROUND

The size control of velopharyngeal opening is an important variable for the acoustic profile characterization of hypernasal speech.

AIM

To investigate frequency spectral aspects of F1, F2, F3, nasal formant (FN) and anti-formant, in Hertz, for vowels [a] and [ã] at different velopharyngeal openings produced in the bulb of a palatal prosthesis replica used by a patient with velopharyngeal insufficiency.

METHOD

Speech recordings were obtained for four words ("pato/mato" and "panto/manto") produced within a carrier phrase in 5 conditions of velopharyngeal functioning: prosthesis with no openings (control condition: CC); prosthesis with bulb opening of 10 mm² (experimental condition with 10 mm² opening: EC10), prosthesis with a 20 mm² opening (EC20), prosthesis with a 30 mm² opening (EC30), and without the prosthesis (ECO). Five speech-language pathologists made a live rating of speech nasality during the reading of an oral passage. The recordings were used for spectral analysis.

RESULTS

F1 values were significantly higher for [a] when compared to [ã] in all conditions. F2 values for [a] in EC20 and EC30 were significantly lower than values in the other conditions, being closer to the values presented for [ã]. F3 values were not significantly different between the testing conditions. There was a relationship between FN and anti-formants, and the auditory perception of nasality for conditions EC10 and EC20.

CONCLUSION

Significant changes were observed in the studied spectral values according to changes in the velopharyngeal opening size.

Magnetic resonance imaging assessment of the velopharyngeal mechanism at rest and during speech in Chinese adults and children

PURPOSE

Recent applications of the magnetic resonance imaging (MRI) technique introduced accurate 3-dimensional measurements of the velopharyngeal mechanism. Further standardization of the data acquisition and analysis protocol was successfully applied to imaging adults at rest and during phonation. This study was designed to test and modify a noninvasive protocol for evaluating young children without using general anesthesia. In addition, the velopharyngeal structures and their maximal motion were compared between adults and children.

METHOD

MRI data were acquired in 12 young adults and 9 children at rest and during speech production. Multiple measurements were made on the velopharyngeal and craniofacial structures as well as on the levator veli palatini muscle.

RESULTS

Most of the ratio measurements of structural shape and maximal motion in the velopharyngeal and craniofacial regions were not significantly different between the adults and the children, despite the fact that the children had much smaller structures than the adults.

CONCLUSION

The proportion of the velopharyngeal mechanism remains stable in young children and adults so that the motions of the velum and pharyngeal walls are adequate to close the velopharyngeal port completely.

Temporal characteristics of nasalization in speakers with and without cleft palate

OBJECTIVE

The purposes of the study were to compare the temporal characteristics of nasalization between speakers with cleft palate with or without cleft lip and normal adult speakers and to investigate the relationship between acoustic temporal measures and perceived nasality.

METHODS

Fifteen speakers with cleft palate with or without cleft lip and 15 speakers without cleft palate aged 13 to 45 years participated in this study. Two listeners judged the degree of nasality in speakers with cleft palate with or without cleft lip. Two distinct acoustic energies derived from the mouth and nose were recorded simultaneously while speakers were producing the speech tasks /pimip/, /pamap/, and /pumup/. Absolute and proportional measures related to nasalization duration were obtained.

RESULTS

Speakers with cleft palate with or without cleft lip exhibited more extensive acoustic nasalization in the time domain than did speakers without cleft palate with or without cleft lip. Speakers without cleft palate with or without cleft lip showed larger nasalization-duration ratios in the high vowel contexts than in the low vowel context. Speakers with cleft palate with or without cleft lip did not exhibit distinct differences in nasalization-duration ratios among the vowel contexts. The acoustic measurements reflecting temporal patterns of oral-nasal acoustic impedance were related to the perception of hypernasality.

CONCLUSIONS

These results suggest that the speakers with cleft palate with or without cleft lip showed longer duration of acoustic nasalization than speakers without cleft palate with or without cleft lip. Temporal characteristics of acoustic nasalization grew longer as the degree of perceived hypernasality increased. The positive correlation between temporal measures of acoustic nasalization and degree of perceived nasality suggests that temporal measures of nasalization would provide supplementary diagnostic information in relation to the degree of hypernasality.