Muscle Tension Dysphonia Group Research Articles

Usefulness of Water-Resistance Straw Phonation in Discrimination of Adductor-Type Spasmodic Dysphonia and Muscle Tension Dysphonia

Objectives: Although Adductor-type spasmodic dysphonia (AdSD) and Muscle tension dysphonia (MTD) show similar phonetic symptoms, the causes and treatment methods are different. Therefore, discrimination is necessary for the proper treatment of the two diseases. The purpose of this study is to investigate the usefulness of Water-resistance straw phonation (WSP) as a diagnostic therapy for the differentiation of AdSD and MTD. To that end, Both patients with AdSD and MTD performed WSP, and their voices was measured before and after diagnostic therapy.Methods: A total of 27 (18 MTD, 9 AdSD) individuals participated in this study. The MTD group (4 male, 14 female) mean age was 30.01 years and the AdSD (2 male, 7 female) group mean age was 31.03. Both groups were treated with diagnostic therapy using WSP which took approximately 90 seconds. The acoustic analysis and auditory–perceptual assessment were completed after diagnostic therapy.Results: The MTD group was significantly lower in Jitter Percent (Jitter) (p= .003), Pitch Perturbation Quotient (PPQ) (p= .007), Fundamental Frequency Variation (vF0) (p= .004), Shimmer Percent (Shimmer) (p= .010), Amplitude Perturbation Quotient (APQ) (p= .012), Peak to Peak Amplitude Variation (vAm) (p= .005) and auditory–perceptual grade (p= .007). However, the AdSD group was not significantly different for all variables after performing the WSP.Conclusion: WSP is one of the methods that relieve laryngeal hypertension. In this study, the voice improvement of the MTD group after diagnostic therapy using WSP meant that the laryngeal hypertension was relieved. This change indicates a high probability of MTD as opposed to AdSD. Whereas, no improvement or worsening of the voice problem suggests neither the probability of MTD nor no confirmation of AdSD. Therefore, a diagnostic therapy using WSP may be useful as one of the evaluation methods for discrimination between AdSD and MTD.

Effects and Differences of Voice Therapy on Spasmodic Dysphonia and Muscle tension dysphonia: A Retrospective Pilot Study.

Laryngeal and voice findings of adductor spasmodic dysphonia (AdSD) and muscle tension dysphonia (MTD) are similar, and it is difficult to distinguish between both disorders. The purpose of this study is to ascertain the effect of voice therapy on MTD and AdSD and clarify their difference. A total of 49 patients, including 22 patients with MTD (MTD group) and 27 patients with AdSD (SD group), were included in the study. The MTD scores were evaluated, and aerodynamic analysis (maximum phonation time [MPT], mean airflow rate [MFR], highest pitch, lowest pitch, and pitch range), perceptual evaluation (Strangulation, Interruption, and Tremor), acoustic analysis (PPQ, APQ, NHR, and DVB), and subjective assessment (voice handicap index-10 [VHI-10]) were performed before and after voice therapy. The MTD score, highest pitch, pitch range, strangulation, PPQ, APQ, NHR, and VHI-10 showed significant improvement after treatment in the MTD groups. On the other hand, the effect of voice treatment on AdSD was poor despite the improvement in the MTD score. This study could serve as a basis for conducting prospective studies to verify the effects of voice therapy on MTD and AdSD.

Vocal parameters, muscle palpation, self-perception of voice symptoms, pain, and vocal fatigue in women with muscle tension dysphonia.

To identify muscle tension dysphonia (MTD) signs and symptoms, as well as to analyze the results of vocal parameters, the physical clinical examination of muscle palpation, the self-perception of vocal symptoms, vocal pain, and fatigue of women with MTD and compare them with women with healthy voices. a cross-sectional study with 45 women (23 with MTD and 22 controls), similar median age between groups. The speech-language and otorhinolaryngological evaluation determined the diagnosis of MTD. All participants responded to the Voice Symptoms Scale (VoiSS), Vocal Fatigue Index (VFI), and Nordic Musculoskeletal Questionnaire (NMQ) protocols. They were also assessed by a palpatory evaluation of the perilaryngeal musculature, auditory-perceptual evaluation, and acoustic analysis of the voice fundamental frequency. The speech sample included sustained vowels "a", "i" and "e" and connected speech, recorded in a silent environment, and submitted to auditory-perceptual evaluation by three judges. In the acoustic analysis, the fundamental frequency and maximum phonation times were extracted. The MTD group had worse results in VoiSS, VFI, and NMQ, in addition to greater resistance to palpation and a high vertical position of the larynx. The vocal parameters also showed greater deviation in the MTD group, except for the fundamental frequency. There was no relationship between vocal symptoms, fatigue, or pain with the general degree of dysphonia in the MTD group, indicating important symptoms in mild or moderate vocal deviations. women with MTD presented vocal symptoms, vocal fatigue, muscle pain, resistance to palpation and deviated vocal parameters when compared to vocally healthy women.

켑스트럼 변수와 랜덤포레스트 알고리듬을 이용한 MTD(근긴장성 발성장애) 여성화자 음성과 정상음성 분류*

This study investigated the acoustic characteristics of sustained vowel /a/ and sentence utterance produced by patients with muscle tension dysphonia (MTD) using cepstrum-based acoustic variables. 36 women diagnosed with MTD and the same number of women with normal voice participated in the study and the data were recorded and measured by ADSV™. The results demonstrated that cepstral peak prominence (CPP) and CPP_F0 among all of the variables were statistically significantly lower than those of control group. When it comes to the GRBAS scale, overall severity (G) was most prominent, and roughness (R), breathiness (B), and strain (S) indices followed in order in the voice quality of MTD patients. As these characteristics increased, a statistically significant negative correlation was observed in CPP. We tried to classify MTD and control group using CPP and CPP_F0 variables. As a result of statistic modeling with a Random Forest machine learning algorithm, much higher classification accuracy (100% in training data and 83.3% in test data) was found in the sentence reading task, with CPP being proved to be playing a more crucial role in both vowel and sentence reading tasks.

Comparative Study of Increased Supraglottic Activity in Normal Individuals and those with Muscle Tension Dysphonia (MTD)

Excessive or disharmonious activity of internal and external laryngeal muscles causes a type of dysphonia known as muscle tension dysphonia (MTD). MTD is often diagnosed based on laryngoscopic findings and clinical history. Several diagnostic and classification systems have so far been proposed based on increased supraglottic activity to determine MTD. Various studies have shown that increased supraglottic activity may also be observed in those with normal voice. The present study aimed to precisely examine the incidence of abnormal muscle tension pattern (aMTP) in those with normal voice in comparison with those with MTD. The secondary goal of this study was comparative examination of acoustic parameters and maximum phonation time (MPT) in the group with MTD and normal individuals. Participants were 75 people with MTD (41 women and 34 men) and 50 individuals with normal voice and no history of dysphonia (20 women and 30 men). Laryngoscopic evaluation was performed for all participants by considering four types of aMTP. Acoustic analyses, including cepstral peak prominence, jitter, shimmer and NHR, as well as MPT examination were performed. A significant difference between the MTD group and control group was observed in all MTPs except for MTP 2 (lateral-to-medial approximation of the false vocal folds) (P=0.367, χ2(1)=0.81). In other MTPs, a significant difference existed between the control and MTD groups in terms of aMTP incidence (P < 0.05). On the four aMTPs, results revealed that one must exercise caution in diagnosing MTD based on MTP 2 (medial compression of ventricular folds), and this must not be the sole criterion for diagnosis. Moreover, cepstral peak prominence and MPT analyses are of high clinical significance.

Effects of Voice Therapy Using the Lip Trill Technique in Patients With Glottal Gap

Lip trills are widely used as a voice warm-up technique among singers. However, little is known about the effects of lip trills in cases of voice disorders. We examined the therapeutic effects of lip trills in patients with glottal gap. Patients with glottal gap were classified into three groups according to the type of gap: gap-only, gap with muscle tension dysphonia (MTD), and a sulcus vocalis group. Patients underwent perceptual, acoustic/aerodynamic analyses, stroboscopic evaluations, and subjective analyses using a questionnaire before and after lip trills. The results were analyzed before and after trills and according to and between the groups. The results in 42 patients were analyzed. Most of the parameters were improved and glottal gap was significantly reduced after trills in all patients. In the gap-only group (n = 19), most of the parameters showed improvement and were within the respective normal ranges, and glottal gap was improved after trills. In the MTD group (n = 13), although many parameters were improved, the improvement was not as prominent as in the gap-only group. In the sulcus vocalis group (n = 10), only some of the parameters were improved and the improvement in glottal gap was limited. Lip trills were an effective treatment for glottal gap. The therapeutic effect was prominent in the gap-only group, followed by the MTD and sulcus vocalis groups. Trills can be used as an adjuvant treatment option in voice therapy in cases of various voice disorders.

Laryngeal Dysfunction in Cough Hypersensitivity Syndrome: A Cross-Sectional Observational Study

Chronic refractory cough (CRC), a phenotype of cough hypersensitivity syndrome (CHS), is a disabling problem. Laryngeal dysfunction may be important in CRC and CHS because laryngeal symptoms are common; however, the role of laryngeal dysfunction in CHS has not been systematically examined. To determine the nature of laryngeal dysfunction in patients with CRC and compare with the related laryngeal conditions of vocal cord dysfunction (VCD) and muscle tension dysphonia (MTD). A cross-sectional analytic design was used. We recruited 69 participants including healthy controls and patients with CRC, VCD, and MTD who were referred for behavioral speech interventions. Participants underwent a comprehensive assessment of laryngeal function during breathing, phonation, and swallowing. Cough frequency was high in patients with CRC (10.2 coughs/h) and VCD (16.5 coughs/h), but low in healthy controls (1.5 coughs/h) (P < .001). Patients with CRC, VCD, and MTD had impaired voice-related quality of life (vs controls, P < .05) and laryngeal hypersensitivity (vs controls, P < .05). Most voice assessment measures (3 out of 4) were significantly impaired in the CRC group compared with controls and were similar to the VCD and MTD groups. Paradoxical vocal fold movement during respiration was present in 47% of the patients with CRC at rest and in 67% after odor challenge. Mediolateral laryngeal constriction during phonation was present in 45% of the participants with CRC, 93% of the participants with VCD (P < .001 vs CC), and 64% of the participants with MTD. Laryngeal dysfunction is common in CRC and CHS and may contribute to CHS mechanisms. Assessment and treatment of laryngeal dysfunction using speech pathology interventions are likely to be beneficial in CHS.

Correlation of the Iranian Voice Quality of Life Profile (IVQLP) with Acoustic Measurements across Three Common Voice Disorders

The Iranian Voice Quality of Life Profile (IVQLP) is a recent culture-based developed tool for assessing the quality of life of dysphonic patients. The research questions addressed here are as follows: (1) Are the correlations between IVQLP scores and values of objective voice measures? (2) Do the correlations differ across the three different voice disorders? The subjects were divided into three groups: muscle tension dysphonia (MTD) (n = 62), benign midmembranous vocal fold lesions (n = 56), and unilateral vocal fold paralysis (UVFP) (n = 32). The study sample consisted of 91 males and 59 females. The individuals had a mean age of 46.53 ± 13.84 years. All of the participants completed the IVQLP questionnaire. The PRAAT software was used to provide acoustic analyses. The correlations between fundamental frequency (F0), perturbation analyses, harmonics-to-noise ratio, and IVQLP data of the three groups of patients were measured using Pearson's correlation. There was a significant correlation between the total score and jitter in the MTD group. For the benign vocal fold lesion group, correlations were significant and relatively strong for numerous analyses. Again, there were numerous significant and strong correlations for the UVFP group. Results may indicate two interpretations. One interpretation of the results is that patients with morphological tissue changes (lesions, paralysis) appear to associate their sense of how their voice problem negatively affects their lives. A second interpretation is that there is perhaps a threshold of vocal perturbation or instability that lends itself to a patient's connection to his or her sense of how the voice affects his or her quality of life.

Brain Activity During Phonation in Women With Muscle Tension Dysphonia: An fMRI Study

The main objectives of this functional magnetic resonance imaging (fMRI) study are (1) to investigate brain activity during phonation in women with muscle tension dysphonia (MTD) in comparison with healthy controls; and (2) to explain the neurophysiological mechanism of laryngeal hyperfunction/tension during phonation in patients with MTD. Ten women with MTD and fifteen healthy women participated in this study. The fMRI experiment was carried out using a block design paradigm. Brain activation during phonation and exhalation was analyzed using BrainVoyager software. The statistical analysis of fMRI data has demonstrated that MTD patients control phonation by use of the auditory, motor, frontal, parietal, and subcortical areas similar to phonation control by healthy people. Comparison of phonation tasks in the two groups revealed higher brain activities in the precentral gyrus, inferior, middle and superior frontal gyrus, lingual gyrus, insula, cerebellum, midbrain, and brainstem as well as lower brain activities in the cingulate gyrus, superior and middle temporal gyrus, and inferior parietal lobe in the MTD group. No differences were found between the two groups regarding exhalation control. The findings in this study provide insight into phonation and exhalation control in patients with MTD. The imaging results demonstrated that in patients with MTD, altered (higher/lower) brain activities may result in laryngeal tension and vocal hyperfunction.

Correlation of VHI-30 to Acoustic Measurements Across Three Common Voice Disorders

Voice disorders that affect the quality of voice also result in varying degrees of psychological and social problems. The research question here is whether the correlations between Voice Handicap Index (VHI)-30 scores and objective acoustic measures differ in patients with different types of voice disorders. The subjects were divided into three groups: muscle tension dysphonia (MTD), benign mid-membranous vocal fold lesions, and unilateral vocal fold paralysis (UVFP). All participants were male. The mean age for the groups were 32.85 ± 8.6 years in the MTD group, 33.24 ± 7.32 years in the benign lesions group, and 34.24 ± 7.51 years in the UVFP group. The participants completed the Persian VHI-30 questionnaire. PRAAT software was used to obtain acoustic analyses. There was a significant correlation between the physical subscale of the VHI-30 and the total score of the VHI-30 and maximum phonation time (MPT) in the MTD group. Also, there was a significant correlation between the total VHI-30 score and the MPT value. There were relatively strong and significant correlations between the physical subscale of the VHI-30 with jitter and shimmer, harmonics-to-noise ratio (HNR) for the group with benign lesions such as nodules and polyps. Also, in this group, there was a significant correlation between the total VHI-30 score and the jitter value. The physical scale had strong and significant correlations between jitter, shimmer, and HNR in the unilateral paralysis group. Findings suggest that although the VHI-30 and the acoustic measurements of voice provide independent information, they are associated to some extent.

Immediate Effects of Humming on Computed Electroglottographic Parameters in Patients With Muscle Tension Dysphonia

To investigate the immediate effects of humming and subsequent um-hum phonation on the computed parameters of electroglottographic (EGG) signals in muscle tension dysphonia (MTD) patients and nondysphonic speakers. We included 21 MTD participants exhibiting both vocal roughness and supraglottic compression, who were able to produce successful humming and um-hum phonation. Twenty nondysphonic participants were selected as controls. Each participant was instructed to perform three phonatory tasks: natural phonation, humming phonation without pitch changes, and subsequent um-hum phonation, that is, humming with a pitch glide up as if agreeing with someone. Acoustic and EGG signals were recorded while the participants performed these tasks. Computed parameters reflecting the irregularities in vocal fold vibrations and the degree of glottal contact were calculated and compared between the tasks. The MTD group showed decreases in both perceptual vocal roughness and acoustic perturbation parameters while performing the tasks. The perturbation parameters of EGG signals and the standard deviation of the contact quotient (CQ) also exhibited significant decreases associated with either of humming or um-hum phonation in both groups. In addition, the CQ exhibited significant increases following humming alone in the MTD group and the combination of humming and um-hum phonation in both groups. These results suggest that the combination of humming without pitch changes and subsequent um-hum phonation have the immediate effect in adjusting the regularity of vocal fold vibration and augmenting the degree of glottal contact in MTD patients as well as nondysphonic speakers, whereas humming alone increases the degree of glottal contact in MTD patients.

Immediate Effectiveness of Humming on the Supraglottic Compression in Subjects with Muscle Tension Dysphonia

Aims: To verify whether humming corrects supraglottic compression in muscle tension dysphonia (MTD) patients. Methods: We enrolled 23 MTD participants (13 male, 10 female) showing supraglottic compression. Each individual was instructed to perform 3 types of phonation under transnasal laryngofiberscopy: natural phonation, humming phonation without pitch change and subsequent um-hum phonation, i.e. humming with pitch glide up as if agreeing with someone. The degree of supraglottic compression was estimated with 2 parameters. The false vocal fold and anterior-posterior indices (the FVF and AP indices) were calculated by normalizing the lateral width and AP length of the visible vocal cords at phonation normalized to the mean vocal cord length at inspiration, respectively. These indices were compared among the tasks. Results: All the MTD participants but 5 females accomplished decreases in the vocal roughness scores upon the phonatory tasks. The whole MTD group showed significant increases in the FVF and AP indices even after humming without pitch change with a dominance of the AP index. The humming-responsive MTD subgroup showed greater increases in both indices than the humming-resistant subgroup. Conclusion: These data demonstrate that humming corrects both the lateral and AP components of supraglottic compression in most MTD patients.

The Correlation Between Voice Handicap Index and Specific Acoustic Measures in Patients With Muscle Tension Dysphonia

Background: With regard to the multidimensional concept of the voice, different assessments are needed to diagnose and treat voice disorders. Additionally, it is important to know how various aspects of voice are compared and related to each other. Objectives: The purpose of this study was to examine the correlation between the Voice Handicap Index (VHI) score and the acoustic measures in different types of Muscle Tension Dysphonia (MTD). Patients and Methods: Eighteen females including 12 with primary MTD (group 1) and 6 with secondary MTD (group 2) participated in this cross-sectional study. All subjects completed VHI and were provided with voice samples including three trials of the sustained vowel /a/ at a comfortable loudness level as well as a connected speech sample. Acoustic measures were performed with Praat software and included fundamental frequency, jitter %, shimmer % and intensity. Results: Certain correlations were found between fundamental frequency in vowel and total VHI, physical, functional and emotional domains of VHI in group 1 (r = 0.636, 0.649, 0.613 and 0.592 respectively). There was good correlation between speaking fundamental frequency and total VHI and its subscales - except the physical subscale - were also correlated. In group 2, the correlations between jitter and total VHI as well as the emotional domain of VHI was very good (r = 0.829, and 0.812 respectively). Furthermore, we found very good correlation between the intensity of speech and functional domain (r = 0.812). Conclusions: VHI and acoustic parameters likely measure different aspects of voice and thus are not interchangeable. However, the correlation between VHI and some laboratory measurements increases in dysphonia of the same nature, origin and same sexuality.

Effectiveness of the Computed Analysis of Electroglottographic Signals in Muscle Tension Dysphonia

Objective: To investigate the usefulness of electroglottography (EGG) parameters in the diagnosis and estimation of efficacy of voice therapy for muscle tension dysphonia (MTD). Patients and Methods: Nineteen MTD participants, an equivalent number of dysphonic (‘organic’) patients with vocal fold lesions and as many normal speakers were enrolled. Acoustic (Ac) and EGG signals during sustained phonation were recorded simultaneously. The period and amplitude perturbation quotient of both signals, the closed quotient (CQ) of EGG signals (mean CQ) and its standard deviation (CQSD) were calculated, and subsequently compared among the three groups. These parameters in the MTD group were compared before and after voice therapy. Results: The perturbation measures of both signals in the MTD group were either as high as or significantly higher than those in the organic group or the control group, respectively. Both the Ac and EGG parameters after therapy significantly decreased. The CQSD, but not mean CQ, also decreased after therapy. Conclusion: EGG parameters related to the regularity of vocal fold vibration, but not to the degree of vocal fold contact (mean CQ), are useful for the diagnosis and estimation of voice therapy outcome in MTD.

Differential Vibratory Characteristics of Adductor Spasmodic Dysphonia and Muscle Tension Dysphonia on High-Speed Digital Imaging

The purpose of this study was to quantify disorder-specific signature kinematic disturbances of vibratory motion in adductor spasmodic dysphonia (AdSD) and muscle tension dysphonia (MTD), in voice disturbances of a severe nature, with the use of high-speed digital imaging (HSDI). A secondary hypothesis of the study was to investigate the sensitivity and specificity of the signature kinematic features obtained from HSDI, in differentiating between AdSD and MTD. We used vibratory features from automated extraction of vocal fold motion waveforms and glottal cycle montage analysis from HSDI for differential kinematic profiling of AdSD and MTD. Novel features of motion irregularities and micromotions (as small as 27 ms) were greater in number for AdSD, whereas reduced motion irregularities, absence of oscillatory breaks, absence of micromotions, and increased hyperfunction characterized the MTD group. Oscillatory breaks (as small as 8 ms), although present only in the AdSD group, were not statistically significant because of their reduced number of occurrences compared to the other features. Further montage analysis of successive glottal cycles of oscillatory breaks in the AdSD group revealed 3 different kinematic patterns within the AdSD group, indicative of likely AdSD with: 1) possible predominant thyroarytenoid muscle involvement, 2) possible predominant cricothyroid muscle involvement, and 3) possible combined involvements of the thyroarytenoid and lateral cricoarytenoid muscles. Four consistent but unique kinematic patterns were identified within the MTD group: 1) diplophonia, 2) vocal fry, 3) breathy phonation, and 4) pressed phonation. Sensitivity and specificity analysis revealed that only motion irregularity was a significant predictor of the presence of AdSD. Fine kinematic analysis from HSDI can be used to aid detailed clinical profiling of the source characteristics of AdSD and MTD.

How Do Individuals Cope With Voice Disorders? Introducing the Voice Disability Coping Questionnaire

Coping is a key concept in psychological medicine, which refers to the way in which people deal with the stress of illness. Voice disorders may have pervasive effects upon the individual's life beyond the vocal impairment yet, there is little reference in current literature as to how people cope with voice problems. This study explored and validated the Voice Disability Coping Questionnaire (VDCQ), a newly developed disease-specific coping measure, which elicits how patients cope with voice problems. Eighty subjects presenting with muscle tension dysphonia (MTD) and adductor spasmodic dysphonia (ASD) completed a 28-item VDCQ as part of an initial assessment protocol before intervention, within a longitudinal study. Principal component analyses were used to investigate the underlying structure of this questionnaire; analyses of variance were used to determine group differences in coping strategies. The principal component analyses generated four coping subscales: "social support," "passive coping," "avoidance," and "information seeking" measured over 15 items. The subscales revealed logical correlations between them. Avoidance and passive coping were found to be used by the ASD group significantly more than the MTD group. This study provided initial evidence for the validity and reliability of the VDCQ; it differentiated between clinical groups and may facilitate a patient-centered approach, which enhances the understanding of voice disorders.

Impact of Muscle Tension Dysphonia on Tonal Pitch Target Implementation in Vietnamese Female Teachers

Muscle tension dysphonia (MTD) is a voice disorder with deteriorated vocal quality, particularly pitch problems. Because pitch is mainly controlled by the laryngeal muscles, and because MTD is characterized by increased laryngeal muscle tension, we hypothesized that it may result in problems in pitch target implementation in tonal languages. We examined tonal samples of 42 Vietnamese female primary school teachers diagnosed with MTD and compared them with 30 vocally healthy female teachers who spoke the same dialect. Tonal data were analyzed using Computerized Speech Lab (CSL-4300B) for Windows. From tonal sampling bases, fundamental frequency (F0) was measured at target points specified by contour examination. Parameters representing pitch movement including time, size, and speed of movement were measured for the falling tone and rising tone. We found that F0 at target points in MTD group was lowered in most tones, especially tones with extensive F0 variation. In MTD group, target F0 of the broken tone in isolation was 37.5 Hz lower (P<0.01) and target F0 of rising tone in isolation was 46 Hz lower (P<0.01) than in control group. In MTD group, speed of pitch fall of the falling tone in isolation was faster than control group by 2.2 semitones/second (st/s) (P<0.05) and speed of pitch rise in the rising tone in isolation was slower than control group by 7.2 st/s (P<0.01). These results demonstrate that MTD is associated with problems in tonal pitch variation.

Effects of Muscle Tension Dysphonia on Tone Phonation: Acoustic and Perceptual Studies in Vietnamese Female Teachers

Muscle tension dysphonia (MTD) is a hyperfunctional voice disorder commonly seen in professional voice users. To date, published acoustic studies of this disorder have mainly focused on nontonal language speakers, and no publication has documented its impact on lexical tone characteristics. In this study, we examined whether and how this voice disorder affected acoustically and perceptually the characteristics of tones in Vietnamese teachers. Voice data were obtained from 42 Vietnamese female primary school teachers diagnosed with MTD and 30 vocally healthy teachers. Tonal data were analyzed using Computerized Speech Lab (CSL-4300B) and Speech Analyzer. Parameters analyzed included the two most important acoustic cues in Vietnamese tones, that is, tonal fundamental frequency (F(0)) and laryngealization. Tonal F(0) was assessed using a factorial analysis of variance with group and career durations as independent variables. Tonal samples were also perceptually assessed by a panel of native speakers of the same dialect. The results showed that MTD lowered tonal F(0) in high tones and tones with extensive fundamental frequency variation. There was also a significant main effect for career duration; in MTD group, tonal F(0) was lower in teachers with longer career duration. The teachers with MTD showed different patterns of laryngealization compared with the control group. Tone perception was poorer for tones with extensive fundamental frequency variation and without a typical phonation type. The results in this group of teachers supported our hypothesis that MTD impairs lexical tone phonation.

Involuntary Glottal Closure during Inspiration in Muscle Tension Dysphonia

The purpose of this study was to examine respiratory function in a group of patients with muscle tension dysphonia (MTD) DESIGN: Cross-sectional analytical study. Participants included 15 people with a diagnosis of MTD referred to speech pathology for management of their voice disorder, fiberoptic evidence of glottal or supraglottic constriction during phonation with or without posterior chink, or bowing combined and deviation in perceptual voice quality. A second group of 15 participants with no history of voice disorder served as healthy controls. Baseline pulmonary function test measures included forced expiratory volume in the first second (FEV1), FVC, FEF25 to 75, FIF50, FEV1/FVC, ratio and FEF50/FIF50 ratio. Hypertonic saline challenge test measures included FEV1 and FIF50 after provocation, dose response slope, and provocation dose. Compared with healthy controls, participants with MTD demonstrated a higher prevalence of glottal constriction during inspiration after provocation with nebulized hypertonic saline as demonstrated by a reduction in FIF50 after the hypertonic saline challenge. There was no significant difference between the MTD and healthy control groups in baseline pulmonary function testing. Participants with MTD demonstrated a higher prevalence than healthy controls of abnormal glottic closure during inspiration similar to paradoxical vocal fold movement (PVFM). This suggests that they either had previously undiagnosed coexisting PVFM or that the condition of MTD could be expanded to include descriptions of aberrant glottic function during respiration. This study enhances the understanding of PVFM and MTD by combining research advances made in the fields of otolaryngology and respiratory medicine.