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Abstract

This study was designed to determine the effect of stimulated vocal loudness on nasalance in individuals with various dysarthria subtypes. Thirty participants produced three stimulated levels of vocal loudness while reading a nonnasal passage. Data included dysarthria classification, vocal sound pressure level, nasalance, and listener perception of nasality. There was not a predictable relationship between a change in vocal sound pressure level (SPL) and a change in nasalance, nor did these changes result in consistent perceptual results. There were, however, dysarthria-specific effects of stimulated vocal loudness on nasality. Further, the study highlighted the importance of corroborating objective data with perceptual findings. Copyright © 2006 by Delmar Learning, a division of Thomson Learning, Inc.
... Although the LSVT did not directly target nasal resonance, the trends of reduced resonance may suggest that the increased eff ort and loudness as taught in the LSVT may have generated greater recruitment of motor units needed for more complete velopharyngeal closure [33]. Th e reduced resonance may alternatively be explained by the increased opening of the oral cavity that occurs with increased loudness. ...
... Th ere was a mismatch between nasalance score and perceived rating of hypernasality. Similar mismatches have been found in previous studies on dysarthric speakers [33][34][35]. Perceptual nasality judgment can be infl uenced by a number of factors including speech intelligibility, articulatory precision, and speaking rate, making reliable judgment of nasality often diffi cult [34] Th is mismatch was not present in TDT as it directly targets other aspects aff ecting nasality perception, such as articulatory precision, speech intelligibility, and speaking rate. ...
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Objective The aim of this study was to investigate the short-term and long-term speech effects of the Lee Silverman Voice Treatment (LSVT) program in a group of individuals with flaccid dysarthria and compare its effectiveness with traditional dysarthria therapy (TDT) methods. Design This study was designed as a randomized controlled trial. Patients and methods The study included 22 patients with flaccid dysarthria who were randomized into two groups and received either the LSVT or the TDT. Both interventions were administered at the same frequency, for 1 h a day, 4 days a week, for 4 weeks. Participants underwent a three-phase assessment: (a) before treatment, (b) immediately after treatment, and (c) 6 months after treatment or follow-up. Outcome measures included auditory perceptual analysis, acoustic and spectral analysis, aerodynamic analysis, nasometry, and Communication Partner questionnaire. Results There was significant improvement in most auditory perceptual analysis and instrumental variables in both treatment groups but most of these improvements were not maintained during follow-up in either group. Comparative statistical analysis revealed no significant differences between the two groups in the three assessment phases in most studied variables. Conclusion The apparent equity between LSVT and TDT in flaccid dysarthria highlights the clinical value of teaching the LSVT method and the potential for this treatment to yield improvements comparable to traditional articulation therapy methods through a technique that is cognitively less demanding. Thus the advantage of LSVT is not the amount of improvement but the less-demanding nature, cognitive-wise, of the technique.
... Clear speech also is consistently accompanied by lengthened segment durations as well as a slower than normal articulation rate (Goberman & Elmer, 2005;Tjaden, Lam, & Wilding, 2013), and some dysarthria studies also have found that an increased vocal intensity is accompanied by lengthened speech durations and a slower than normal rate (e.g., Darling & Huber, 2011;Dromey, 2000;Tjaden, Lam, & Wilding, 2013). Finally, the impact of an increased vocal intensity on velopharyngeal function appears to depend on the nature of the dysarthria (McHenry & Liss, 2006). The effect of clear speech on velopharyngeal function in dysarthria has not been systematically studied, although clear speech has been identified as a promising therapeutic technique for mild velopharyngeal impairment in the form of hypernasality (Yorkston et al., 2001). ...
Article
Purpose: The impact of clear speech or an increased vocal intensity on consonant spectra was investigated for speakers with mild dysarthria secondary to multiple sclerosis or Parkinson's disease and healthy controls. Method: Sentences were read in habitual, clear, and loud conditions. Spectral moment coefficients were obtained for word-initial and word-medial /s/, /ʃ/, /t/, and /k/. Global production differences among conditions were confirmed with measures of vocal intensity and articulation rate. Results: Static or slice-in-time first moments (M1) for loud differed most frequently from habitual, but neither loud nor clear enhanced M1 contrast for consonant pairs. In several instances, the clear and loud conditions yielded stable or nonvarying fricative M1 time histories. Spectral contrast was reduced for word-medial versus word-initial consonant pairs. Conclusion: The finding that the loud and especially clear condition yielded fairly subtle changes in consonant spectra suggests these global techniques may minimally enhance consonant segmental production or contrast in mild dysarthria. The robust effect of word position on consonant spectra indicates that this variable deserves consideration in future studies. Future research also is needed to investigate how or whether consonant production bears on the improved intelligibility previously reported for these global dysarthria treatment techniques.
... is known in this regard about increased loudness (Goberman & Elmer, 2005;Tjaden & Wilding, 2011;Yorkston, Hakel, et al., 2007). The impact of rate reduction and increased vocal intensity on resonance in dysarthria also has been studied (McHenry, 1997;McHenry & Liss, 2006;Yorkston & Beukelman, 1981), and clear speech holds promise as a therapy technique for mild hypernasality in dysarthria (Yorkston et al., 2001). Although knowledge of how global therapy techniques affect respiratory-phonatory behavior and resonance in dysarthria is important, of primary interest to the current study is how rate reduction, increased vocal intensity, and clear speech impact articulatory behavior in dysarthria, as inferred from the acoustic signal. ...
Article
The impact of clear speech, increased vocal intensity and rate reduction on acoustic characteristics of vowels was compared in Parkinson's disease (PD), Multiple Sclerosis (MS) and healthy controls. Speakers read sentences in Habitual, Clear, Loud and Slow conditions. Variations in clarity, intensity and rate were stimulated using magnitude production. Formant frequency values for peripheral and non-peripheral vowels were obtained at 20%, 50% and 80% of vowel duration to derive static and dynamic acoustic measures. Intensity and duration measures were obtained. Rate was maximally reduced in the Slow condition and vocal intensity was maximized in the Loud condition. The Clear condition also yielded a reduced articulatory rate and increased intensity, although less than for the Slow or Loud conditions. Overall, the Clear condition had the most consistent impact on vowel spectral characteristics. Spectral and temporal distinctiveness for peripheral-non-peripheral vowel pairs was largely similar across conditions. Clear speech maximized spectral distinctiveness for peripheral and non-peripheral vowels produced by speakers with PD and MS while also reducing rate and increasing vocal intensity. These results suggest a speech style focused on increasing articulatory amplitude yields the most robust changes in vowel segmental articulation.
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The effectiveness of computer speech recognition as an objective measure of intelligibility was explored. A commercially available program was assessed following the manufacturer's protocol to analyze speech samples from three speakers without neurogenic speech disorders, one speaker with moderate spastic dysarthria, and a synthesized speech sample. The system identified the synthesized speech most accurately, and the speech of the speaker with dysarthria least accurately. To improve clinical relevance, a variation of the recommended protocol was performed. The first author provided a referent speech sample, and typically used intelligibility tests produced by three speakers with dysarthria were assessed. These results were compared with intelligibility judgments from a large number of everyday listeners. Compared to the everyday listener results, the software judged all samples much less accurately. Single word intelligibility was particularly disparate because of the prediction model used by the recognition system. In addition, replicability was poorer than expected, again, due to the prediction model. Further work, modifying the software's referent sample as well as assessing other recognition programs, is proposed. These programs have the potential for providing reliable pre-post therapy analysis and a stable point of comparison across clinicians and settings.
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Objectives: Nasality is one of the important parameters in pathology of voice resonance. Voice of normal adults has nasality to some extent. It appears that nasality, like other parameters of voice, can be affected by loudness which can be measured in experimental evaluations. This study was conducted to determine the effect of vocal loudness on nasalance of vowels in normal adults and to identify the relationship between these two factors in 18-28 year-old normal Persian-speaking adults. Methods: In this descriptive-analytic and cross sectional study, sample voices of sixty-five randomly selected male and female 18 to 28 year-old normal Persian-speaking students of Rehabilitation Faculty in Tehran University of Medical sciences were studied. Mean of Nasalance in Persian vowels was computed with Nasal View software. The findings were analyzed with descriptive statistical analysis and one-way ANOVA. Results: Maximum nasalance was in low voice and minimum nasalance was in loud voice in both men and women subjects. The statistical results show that nasalance in 3 levels of low, normal and loud voices have significant differences (P
Article
This study examined the extent to which articulatory rate reduction and increased loudness were associated with adjustments in utterance-level measures of fundamental frequency (F(0)) variability for speakers with dysarthria and healthy controls that have been shown to impact on intelligibility in previously published studies. More generally, the current study sought to compare and contrast how a slower-than-normal rate and increased vocal loudness impact on a variety of utterance-level F(0) characteristics for speakers with dysarthria and healthy controls. Eleven speakers with Parkinson's disease, 15 speakers with multiple sclerosis, and 14 healthy control speakers were audio recorded while reading a passage in habitual, loud, and slow conditions. Magnitude production was used to elicit variations in rate and loudness. Acoustic measures of duration, intensity and F(0) were obtained. For all speaker groups, a slower-than-normal articulatory rate and increased vocal loudness had distinct effects on F(0) relative to the habitual condition, including a tendency for measures of F(0) variation to be greater in the loud condition and reduced in the slow condition. These results suggest implications for the treatment of dysarthria.
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The purpose of this study was to assess the effect of speaking rate variation on aerodynamic and acoustic measures of velopharyngeal (VP) function. Twenty-seven healthy adult speakers (14 males, 13 females) participated in the study. The modified pressure-flow method was used to collect aerodynamic data of /m/ and /p/ segments in the word 'hamper' and the utterances 'Mama made some lemon jam' (MMJ) and 'Buy Bobby a puppy' (BBP). SPL was collected simultaneously with aerodynamic data for all utterances. A Nasometer was used to obtain nasalance scores and nasalance distance for MMJ and BBP. Sentences were produced at normal, fast, slow, and slowest speaking rates. The results showed that nasal airflow and VP orifice area were unaffected by speaking rate variations in males and females, whereas intra-oral pressure appeared to decrease as speaking rate slowed for both speaker groups. However, this effect was removed by statistically controlling SPL. Nasalance and nasalance distance (MMJ-BBP) did not change with speaking rate variation. There was a statistical difference between nasalance scores produced by male and female speakers. The results suggested that aerodynamic and acoustic measures of velopharyngeal function are not affected by variation in speaking rate in healthy males and females.
Article
Background: Hypernasality is a common feature of non-progressive dysarthria. However, limited research has investigated the effectiveness of treatments for this impairment. Preliminary research has revealed positive effects on nasalance when using increased loudness in certain non-progressive dysarthric speakers. However, the long-term effects of loud speech on nasalance as part of a structured intervention such as Lee Silverman Voice Treatment (LSVT) are yet to be investigated in this population. Aims: The study aimed to investigate the short- and long-term effects of LSVT on hypernasality (perceptual ratings and degree of nasalance) in non-progressive dysarthria; and secondly, to evaluate the effects of traditional dysarthria therapy on these same measures, in comparison with the effects of LSVT. Methods & procedures: Ten non-progressive dysarthric speakers with varying levels of hypernasality (taken from a larger research study) were randomly allocated to receive LSVT((R)) (n = 5) or individually tailored traditional dysarthria therapy (n = 5). Both treatments were administered four times weekly for 4 weeks (that is, 16 x 1-hour sessions). Participants were assessed twice before treatment, twice immediately post-treatment, and twice at follow-up 6 months post-treatment using a perceptual rating task performed by two independent speech pathologists, and the Nasometer. Changes to individual mean nasalance scores were compared against clinically significant criterion and perceptual ratings were analysed descriptively. Outcomes & results: Three out of five participants demonstrated reductions in perceived hypernasality immediately following LSVT, but these changes were maintained at follow-up for only one participant. Two of these three participants demonstrated a corresponding reduction in mean nasalance. Limited changes in perceived hypernasality and nasalance scores were found following traditional dysarthria therapy, with only one participant exhibiting reduced nasalance at follow-up. Conclusions & implications: Due to the small sample size in the present research and variability between participants, further exploration into the effects of LSVT on nasality with a larger population with different dysarthria types is essential.
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Velopharyngeal deficits are a common component of dysarthria following neurogenic insults. Compensatory strategies may minimize the impact of velopharyngeal deficits on speech production. Velopharyngeal airway resistance measures were obtained for 28 subjects with traumatic brain injury. The measures were converted to velopharyngeal orifice area estimates. Data are reported for the subjects' habitual loudness and for increased vocal effort. Eighty-nine percent of the subjects decreased velopharyngeal orifice area by increasing vocal effort. The decrease ranged from 0.10 mm 2 to 20.19 mm 2. In several cases, the change would likely affect perceived hypernasality. The reduction in velopharyngeal orifice area with increased vocal effort reflects an ability to compensate for velopharyngeal deficits, as well as a generalization of effects across the speech mechanism. Programs such as the Lee Silverman Voice Treatment, designed to establish high phonatory effort, may be of benefit.
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Data were obtained from 31 subjects who had incurred a traumatic brain injury (TBI). Two expert listeners judged nasality using direct magnitude estimation with a referent. They rated samples of the first sentence of the Rainbow Passage, played backwards, with all pauses removed. Sensitivity was good for nasalance, velopharyngeal airway resistance, and velopharyngeal orifice area, indicating that these measures would accurately identify an individual as nasal. Specificity was reduced, and was adequate only for nasalance. The reduced specificity was due to a high number of false positives, i.e. perceived nasality in the absence of objective corroboration. Analysis of the false positives revealed that a slow speaking rate could mislead a listener's perception of nasality. Overall, for individuals with dysarthria following TBI, the measure of nasalance may most accurately reflect listener perception of nasality.
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Listeners judged the dissimilarity of pairs of synthesized nasal voices that varied on 3 dimensions. Separate nonmetric multidimensional scaling (MDS) solutions were calculated for each listener and the group. Similar 3-dimensional solutions were derived for the group and each of the listeners, with the group MDS solution accounting for 83% of the total variance in listeners' judgments. Dimension 1 ("Nasality") accounted for 54% of the variance, Dimension 2 ("Loudness") for 18% of the variance, and Dimension 3 ("Pitch") for 11% of the variance. The 3 dimensions were significantly and positively correlated with objective measures of nasalization, intensity, and fundamental frequency. The results of this experiment are discussed in relation to other MDS studies of voice perception, and there is a discussion of methodological issues for future research.
Prosthetic management of velopharyngeal incompetence with a palatal lift is now advocated for patients who have structurally adequate but dysfunctional velopharyngeal mechanisms. Additional data are needed to examine the effectiveness of a palatal lift for the broad variety of patients who receive such management. The purpose of this research was to determine the degree of change in oronasal speech quality due to the presence of a palatal lift in patients for whom a palatal lift had been constructed. Nineteen patients who had been fitted with a palatal lift were examined as part of their routine clinical management. Ratings of hypernasal resonance and hyponasal resonance were recorded when the lift was removed and when it was in place. Nasalance measures were also obtained with the lift in place and with the lift removed. Mean group ratings of hypernasality were significantly reduced, and mean group ratings of hyponasality were significantly increased. Mean group nasalance measures were similarly altered by the presence of the lift. Considerable variability was found among the patients, a finding that supports careful consideration of individual patient characteristics when palatal lift management is being planned.
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The purpose of the present investigation was to study the interrelationships among Tonar II, pressure-flow, and listener judgments of hypernasality in a consecutive series of patients. The subjects employed were 124 children and adults seen for evaluation at the University of North Carolina Oral-Facial and Communicative Disorders Program. The results indicated that nasalance scores and clinical ratings of hypernasality change systematically among patients as a function of their pressure-flow categorization. A discussion is presented concerning the impact that differential use of information from these assessment techniques can have upon patient management.
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This study correlated measures of nasalance computed by the Nasometer with listener judgments of nasality. The subjects were 25 children with craniofacial disorders who spoke three passages, each containing a different proportion of nasal consonants. The results showed a significant but modest correlation between nasalance and nasality when nasal consonants (/m, n, eta/) were not included in the speech passage. When nasal consonants were included in the passage nasalance was unrelated to judgments of hypernasality.
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The nasality of 19 subjects with upper motor neuron (UMN) damage following cerebrovascular accident (CVA), and 19 control subjects matched for age and sex, was investigated using both perceptual judgements of nasality and a modified version of the nasal accelerometric procedure described by Horii (1980). Nasality indices were calculated for each subject during the production of a series of nasal and non-nasal sounds, words, and sentences. Statistical comparison of the two groups revealed that the CVA subjects had significantly higher nasality indices on the production of nonnasal speech tasks than the controls. No significant difference was noted between the two groups on nasal tasks. Individual case by case examination of the accelerometer data confirmed the presence of hypernasality in 7 of the 19 CVA subjects. In contrast to the instrumental findings, the results of the perceptual judgements of nasality identified the presence of hypernasality, hyponasality, and normal nasal resonance within the CVA group.
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The effects of variation in speaking rate on relative nasal airflow (percent nasal flow) and on the perception of nasality were examined. In addition, the effects of gender and speech rate elicitation techniques (metronome-controlled, self-controlled) were examined. Nineteen normal speakers each produced a stimulus phrase containing nonnasal sounds. Oral and nasal airflows were measured using the Rothenberg aerodynamic system. Results indicated that percent nasal flow and perception of nasality were both greater at slow speaking rates compared to normal and fast rates. Males were perceived as more nasal than females. The metronome-controlled rates were associated with greater nasality than the self-controlled rates. Discussion focuses on physiological correlates to these findings.
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To determine whether speech hypernasality in subjects born with cleft palate can be reduced by graded velopharyngeal resistance training against continuous positive airway pressure (CPAP). Pretreatment versus immediate posttreatment comparison study. Eight university and hospital speech clinics. Forty-three subjects born with cleft palate, aged 3 years 10 months to 23 years 8 months, diagnosed with speech hypernasality. Eight weeks of 6 days per week in-home speech exercise sessions, increasing from 10 to 24 minutes, speaking against transnasal CPAP increasing from 4 to 8.5 cm H(2)0. MAIN OUTCOME MEASURES Pretreatment to immediate posttherapy change in perceptual nasality score based on blinded comparisons of subjects' speech samples to standard reference samples by six expert clinician-investigators. Participating clinical centers treated from two to nine eligible subjects, and results differed significantly across centers (interaction p =.004). Overall, there was statistically significant reduction in mean nasality score after 8 weeks of CPAP therapy, whether weighted equally across patients (mean reduction = 0.20 units on a scale of 1.0 to 7.0, p =.016) or across clinical centers (mean = 0.19, p =.046). This change was about one-sixth the maximum possible reduction from pretreatment. Nine patients showed reductions of at least half the maximum possible, but hypernasality of eight patients increased at least 30% above pretreatment level. Most improvement was seen during the second month when therapy was more intense (p =.045 for nonlinearity). No interactions with age or sex were detected. Patients receiving 8 weeks of velopharyngeal CPAP resistance training showed a net overall reduction in speech hypernasality, although response was quite variable across patients and clinical centers. The net reduction in hypernasality is not readily explainable by random variability, subject maturation, placebo effect, or regression to the mean. CPAP appears capable of substantially reducing speech hypernasality for some subjects with cleft palate.
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This study assessed listener agreement levels for nasality ratings, and the strength of relationship between nasality ratings and nasalance scores on one hand, and listener clinical experience and formal academic training in cleft palate speech on the other. The listeners were 12 adults who represented four levels of clinical experience and academic training in cleft palate speech. Three listeners were teachers with no clinical experience and no academic training (TR), three were graduate students in speech-language pathology (GS) with academic training but no clinical experience, three were craniofacial surgeons (MD) with extensive experience listening to cleft palate speech but with no academic training in speech disorders, and three were certified speech-language pathologists (SLP) with both extensive academic training and clinical experience. The speech samples were audio recordings from 20 persons representing a range of nasality from normal to severely hypernasal. Nasalance scores were obtained simultaneously with the audio recordings. Results revealed that agreement levels for nasality ratings were highest for the SLPs, followed by the MDs. Thus, the more experienced groups tended to be more reliable. Mean nasality ratings obtained for each of the rater groups revealed an inverse relationship with experience. That is, the two groups with clinical experience (SLP and MD) tended to rate nasality lower than the two groups without experience (GS and TR). Correlation coefficients between nasalance scores and nasality judgments were low to moderate for all groups and did not follow a pattern.