Predicting Dysphonia by Measuring Surface Electromyographic Activity of the Supralaryngeal Muscles.

PURPOSE: This study set out to investigate whether individuals with dysphonia, as determined by either self-assessment or clinician-based auditory-perceptual judgment, exhibited differences in perilaryngeal muscle activities using surface electromyography (sEMG) during various phonatory tasks. Additionally, the study aimed to assess the effectiveness of sEMG in identifying dysphonic cases. METHOD: A total of 77 adults (44 women, 33 men, Mage = 30.4 years) participated in this study, with dysphonic cases identified separately using either a 10-item Voice Handicap Index (VHI-10) or clinician-based auditory-perceptual voice quality (APVQ) evaluation. sEMG activities were measured from the areas of suprahyoid and sternocleidomastoid muscles during prolonged vowel /i/ phonations at different pitch and loudness levels. Normalized root-mean-square value against the maximal voluntary contraction (RMS %MVC) of the sEMG signals was obtained for each phonation and compared between subject groups and across phonatory tasks. Additionally, binary logistic regression analysis was performed to determine how the sEMG measures could predict the VHI-10-based or APVQ-based dysphonic cases. RESULTS: Participants who scored above the criteria on either the VHI-10 (n = 29) or APVQ judgment (n = 17) exhibited significantly higher RMS %MVC in the right suprahyoid muscles compared to the corresponding control groups. Although the RMS %MVC value from the right suprahyoid muscles alone was not a significant predictor of self-evaluated dysphonic cases, a combination of the RMS %MVC values from both the right and left suprahyoid muscles significantly predicted APVQ-based dysphonic cases with a 69.66% fair level. CONCLUSIONS: This study found that individuals with dysphonia, as determined by either self-assessment or APVQ judgment, displayed more imbalanced suprahyoid muscle activities in voice production compared to nondysphonic groups. The combination of the sEMG measures from both left and right suprahyoid muscles showed potential as a predictor of dysphonia with a fair level of confidence. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25112804.

Surface electromyographic (sEMG) activity of the suprahyoid and sternocleidomastoid muscles in pitch and loudness control.

Purpose: This study set out to determine the contributions of the suprahyoid and sternocleidomastoid (SCM) muscles in changing pitch and loudness during phonation among vocally healthy populations. Method: Thirty-nine participants were first recruited, and twenty-nine of them who passed the screening test (Voice Handicap Index [VHI]-10 score ≤11, auditory-perceptual voice rating score ≤2) were finally selected (mean age = 28.2 years). All participants were measured for their surface electromyographic (sEMG) activity collected from the bilateral suprahyoid and SCM muscles when producing the vowel /a/, /i/, and /u/ in natural (baseline) and at different pitch (+3, +6, -3, -6 semitones) and loudness (+5, +10, -5 dB) levels. Linear mixed-effects models were performed to determine the influencing factors on the root-mean-square percentage of maximal voluntary contraction (RMS %MVC) value of the sEMG signals. Results: Compared with the baseline, a significant decrease of RMS %MVC was found in the suprahyoid muscles during overall phonations of lower pitches (-3 and -6 semitones) and loudness (-5 dB). However, no significant change was detected when producing speech at higher pitch (+3 and +6 semitones) and loudness (+5 and +10 dB) levels. Among the three vowels, /i/ demonstrated significantly higher RMS %MVC than those of /a/ and /u/. The SCM muscles, however, did not show any significant change in the RMS %MVC values among different vowels in relation to the pitch and loudness changes. When the muscles were compared across the two sides, significantly higher RMS %MVC was found in the right side of the suprahyoid (in pitch and loudness control) and SCM (in pitch control) when compared to the left side. Conclusions: The suprahyoid muscle activities were significantly decreased when producing lower pitches and intensities compared to the natural baselines. The production of sustained /i/ required significantly more suprahyoid muscle activities than those of /a/ and /u/. The SCM muscles did not show much sEMG activity in any of the pitch and loudness levels, which could be used potentially as the calibration or normalization of peri-laryngeal sEMG measurement. The findings also showed a tendency for bilateral asymmetry in the use of suprahyoid and SCM muscles.

Fatigue-Related Change in Surface Electromyographic Activities of the Perilaryngeal Muscles.

PURPOSE: This study set out to quantify the fatigue-related changes in surface electromyographic (sEMG) activities of the perilaryngeal muscles following a vocal loading task. METHOD: Thirty-six young healthy participants (M age = 22.4 years) with normal voice performed karaoke singing for at least 100 min. Before the singing task, all participants underwent the sEMG measure and completed a Perceived Vocal Fatigue Score (P-VFS) questionnaire. After the singing task, all participants were immediately measured with the P-VFS again. Half of the participants were then measured for their sEMG immediately after their karaoke singing task, and the other half were given 20 min of rest before undertaking the sEMG measure. The P-VFS and the median frequency (MDF) of the sEMG signals collected from the suprahyoid, infrahyoid, and sternocleidomastoid muscles before and after the singing task were compared using a linear mixed-effects model. RESULTS: All participants reported a perceived vocal fatigue after singing, with a significantly increased P-VFS. Compared with the presinging baseline, the MDF of the sEMG signals in perilaryngeal muscles was significantly lower immediately after the singing task. Such a significant difference was also found after 20 min following the singing task. CONCLUSIONS: The MDF analysis of the sEMG signals could identify and quantify the performance vocal fatigue contributed by perilaryngeal muscles following a vocal loading task. The findings also showed that such fatigue in perilaryngeal muscles, as far as sEMG activities are concerned, can last for at least 20 min.

Comparing the Effects of Self-Generated and Platform-Generated Whole Body Vibration on Vocal Fatigue.

OBJECTIVES: A whole body vibration platform using vertical oscillation has been shown to be efficacious in reducing vocal fatigue in adults. This study aimed to investigate whether this platform-generated whole body vibration was unique in reducing vocal fatigue by comparing it with self-generated whole body vibration. METHODS: Twenty-four female adults (mean age = 23.96 years) were randomly assigned to one of the following three groups: a machine-generated whole body vibration group (N = 8), a self-generated whole body vibration group (N = 8), and a placebo vocal resting group (N = 8). All participants performed a karaoke singing task for at least 95 minutes. Each participant received 10 minutes of platform-generated vibration, self-vibration, or sham localised vibration (placebo group with basically voice rest only), according to their group allocation. Vocal function ability, measured by the highest fundamental frequency produced, and a self-reported vocal fatigue score were evaluated at three time points: baseline (prefatigue), after the singing task (post-fatigue) and post-vibration. RESULTS: The study revealed that machine-generated whole body vibration was significantly better at improving vocal fatigue than self-generated whole body vibration or voice rest. CONCLUSION: The findings support previous research that machine-generated whole body vibration is effective in reducing vocal fatigue. The non-significant results of self-generated whole body vibration in terms of relieving vocal fatigue suggest that inadequate vibration frequency or amplitude together with leg muscle fatigue may have been the main factor of ineffectiveness.

Profiles of polypharmacy in older adults and medication associations with signs of aspiration.

BACKGROUND: Polypharmacy and specific medication classes are prevalent in older adults. Their relationships with swallowing disorders are not well explored, which would best be managed holistically, with consideration of medication profiles. This study aimed to establish profiles of polypharmacy in older adults and investigate the associations of polypharmacy and medication class with signs of aspiration during swallowing. METHODS: This was a secondary retrospective analysis of data from 291 adults aged 60 years and older. Polypharmacy was profiled numerically and described. Multivariate logistic regression was used to identify associations between medication classes with signs of aspiration, while controlling for independent variables of demographics, functional status, and medical history. RESULTS: Three distinct profiles of polypharmacy were described. Higher numbers of medications were associated with higher age, lower functional status, nursing home residency, multimorbidity, and showing signs of aspiration. Thirty-four classes of medications were found in this study, benzodiazepines were the only class independently associated with signs of aspiration. CONCLUSIONS: Different profiles of polypharmacy can be observed in older adults, but none were independently associated with signs of aspiration. In addition to known demographic and functional status variables, benzodiazepine-use was found to be independently associated with signs of aspiration (p = .005, B = 7.94).

Vibrational Therapies for Vocal Fatigue.

BACKGROUND: Vibration is commonly used to relax tension in the limb and truck muscle. Vibration used directly on the muscle concerned and vertical vibration used on the whole-body through a foot platform have been reported in the literature to be useful to release muscle tension. AIM: The present study investigated the effect of indirect whole-body vibration (WBV) and direct localized perilaryngeal vibration (LPV) on the phonatory functions of nondysphonic individuals with vocal fatigue. METHODS: Forty-four subjects (mean age = 21.67 years) with normal voice, were randomly assigned to either the WBV group, the LPV group, or the Control (sham hand-held vibratory device) group. They performed karaoke singing for at least 95 minutes. They then received either WBV through a Turbosonic vibratory machine, LPV with a Novofan vibrator, or a sham vibrator for 10 minutes. The highest pitch produced, and self-reported vocal fatigue score were taken before singing, after singing, and after the intervention. Data were analyzed separately for the gender subgroups. RESULTS: All subject groups showed significant reduction of vocal function (highest pitch production, and vocal fatigue score) after singing. Following the vibrational interventions, both the WBV and LPV groups showed significantly recovery in the highest pitch production and the perception of vocal fatigue (P < 0.002) than the Control groups. CONCLUSION: Vibrational therapy, whether it is localized vibration on the peri-laryngeal muscles, or whole-body vibration, is more effective than voice rest per se in relieving vocal fatigue. Vibrational methods are recommended for treating vocal fatigue.

Factors associated with signs of aspiration in older adults: A prospective study.

This was a prospective cohort design study that followed a group of older adults for up to 12 months. Two hundred and ninety-one participants with a mean age of 81.4 ± 9.1 years were recruited. Signs of aspiration were screened by the Yale Swallow Protocol. Variables investigated for risk were oromotor functions, self-perception of swallowing function, cognitive function, and medical history. Seventy participants were revisited for a follow-up aspiration screening 8 to 9 months later. Multivariate logistic regression found that male sex, need for assistance for feeding and mobility, reduced cognitive function, subjective judgement of swallowing function, and oromotor function were major variables that can be used to screen for older adults who may require referrals for swallowing assessment. Those who continue to show signs of aspiration across time exhibit a more frail profile than their counterparts who do not.

Elicitation of Minimum and Maximum Fundamental Frequency and Vocal Intensity: Discrete Half Steps Versus Glissando.

PURPOSE: To investigate the effect of elicitation method, either discrete half steps or glissando, on the minimum fundamental frequency, maximum fundamental frequency, minimum vocal intensity, and maximum vocal intensity. METHOD: Fifty-six healthy-voice participants (28 males and 28 females) ranging from 18 to 25 years of age participated in the study. Each participant performed both the discrete half steps and the glissando procedure. The minimum frequency, maximum frequency, minimum intensity, and maximum intensity values elicited by each task were analyzed. A portion of participants (five males and five females) returned within 3 weeks to repeat the whole procedure to determine test-retest reliability. RESULT: The results of Pearson's correlation demonstrated all measures were positively significantly correlated. However, the results of paired t tests showed significant difference between elicitation methods, where discrete half steps could elicit maximal vocal performance better than glissando in terms of minimum frequency, maximum frequency, and minimum intensity. Discrete half steps could elicit higher maximum intensity than glissando in males to a greater extent than in females. CONCLUSION: The difference in performance elicited by the two procedures may be considered acceptable under some situations (eg, time constraint, patient fatigue). In the clinical setting, the clinician should select the appropriate procedure with the consideration of time and assessment purpose.

Parental knowledge, attitudes, and practices about vocal hygiene for their children in Chengdu, a city from China.

This study aimed to investigate the knowledge, attitudes, and practices of parents towards vocal hygiene for their children and explore the barriers against implementation of vocal hygiene in Chengdu, a city from mainland China.An online questionnaire on knowledge, attitudes, and practice was available for parents to complete between March 1 and March 31, 2017. The questionnaire included 5 sections, general demographics; knowledge; attitudes; practices and barriers; and expectation. Scores were calculated for each category of knowledge, attitudes, and practices; and were compared using nonparametric Mann-Whitney U tests between the parents with and without a history of voice disorders. The internal consistency was assessed by Cronbach alpha coefficient. The correlations between vocal hygiene knowledge, attitude, and practice were analyzed using Spearman correlation test.The questionnaire was completed by 1075 parents. There were certain misconceptions in vocal hygiene knowledge among parents, and the parents had higher level knowledge of positive factors than negative factors about vocal hygiene. Attitudes towards vocal hygiene were positive. Practices of vocal hygiene were poor. The most common barriers to implementation of vocal hygiene practices were related to lack of awareness and knowledge for this topic.The level of parental vocal hygiene knowledge, practice, and barriers suggest that carry out vocal hygiene programs extremely urgent for school-aged children and their parents.

Mandarin (Simplified) Chinese Version of the Voice Activity and Participation Profile: Adaptation and Validation.

OBJECTIVE: The purpose of this study was to evaluate the reliability and validity of the Mandarin (simplified) Chinese version of Voice Activity and Participation Profile (MC-VAPP) in mainland China. METHODS: This study enrolled 786 subjects from February 2015 to March 2017, including 456 individuals with voice disorders (dysphonic group) and 330 vocally healthy individuals (nondysphonic group). The internal consistency (Cronbach alpha coefficient), test-retest reliability (intraclass correlation coefficient [ICC]), and differences in the MC-VAPP scores were compared between the two groups. Exploratory factor analysis was performed. The receiver operating characteristic curve and cutoff point were calculated. RESULTS: The MC-VAPP had a high internal consistency. Cronbach alpha coefficients for the subsection scores were from 0.86 and 0.96, with 0.98 for the total score. Test-retest reliability was high for the total score (ICC = 0.98). The four factors' cumulative contribution was determined to be 74.68%. The dysphonic participants displayed significantly higher total score and subsection scores than the nondysphonic participants (P < 0.001). There were significant differences in total activity limitation scores and the total participation restriction scores between the two groups (P < 0.001). The cutoff point for screening between the two groups was 36.5, with a sensitivity of 76.80% and specificity of 80.30%. CONCLUSION: The MC-VAPP is a reliable and valid instrument for the evaluation of voice-related quality of life in Chinese-speaking individuals. It is also recommended that the MC-VAPP would be a useful tool for screening individuals with and without voice disorders based on the cutoff value of 36.5.

Adaptation and validation of Mandarin Chinese version of the pediatric Voice Handicap Index (pVHI).

OBJECTIVE: The aim of this study was to adapt and validate the English version of pediatric voice handicap index (pVHI) into Mandarin Chinese. METHODS: A cross-sectional study was performed from May 2016 to April 2017. A total of 367 parents participated in this study, and 338 parents completed the translated questionnaire without missing data, including 213 parents of children with voice disorders (patients group), and 125 parents of children without voice disorders (control group). The internal consistency, test-retest reliability, contents validity, construct validity, clinical validity, and cutoff point were calculated. RESULTS: The most common voice disorder in the patients group was vocal fold nodules (77.9%), followed by chronic laryngitis (18.8%), and vocal fold polyps (3.3%). The prevalence for voice disorders was higher in boys (67.1%) than girls (32.9%). The most common vocal misuse and abuse habit was shouting loudly (n = 186, 87.3%), followed by speaking for a long time (n = 158, 74.2%), and crying loudly (n = 99, 46.5%). The internal consistency for the Mandarin Chinese version of pVHI was excellent in patients group (Cronbach α = 0.95). The inter-class correlation coefficient indicated strong test-retest reliability (ICC = 0.99). The principal-component analysis demonstrated three-factor eigenvalues greater than 1, and the cumulative proportion was 66.23%. The mean total scores and mean subscales scores were significantly higher in the patients group than the control group (p < 0.05). The physical domain had the highest mean score among the three subscales (functional, physical and emotional) in the patients group. The optimal cutoff point of the Mandarin Chinese version of pVHI was 9.5 points with a sensitivity of 80.3% and a specificity of 84.8%. CONCLUSION: The Mandarin Chinese version of pVHI was a reliable and valid tool to assess the parents' perception about their children's voice disorders. It is recommended that it can be used as a screening tool for discriminating between children with and without dysphonia.

Indicators of Dysphagia in Aged Care Facilities.

Purpose: The current cross-sectional study aimed to investigate risk factors for dysphagia in elderly individuals in aged care facilities. Method: A total of 878 individuals from 42 aged care facilities were recruited for this study. The dependent outcome was speech therapist-determined swallowing function. Independent factors were Eating Assessment Tool score, oral motor assessment score, Mini-Mental State Examination, medical history, and various functional status ratings. Binomial logistic regression was used to identify independent variables associated with dysphagia in this cohort. Results: Two statistical models were constructed. Model 1 used variables from case files without the need for hands-on assessment, and Model 2 used variables that could be obtained from hands-on assessment. Variables positively associated with dysphagia identified in Model 1 were male gender, total dependence for activities of daily living, need for feeding assistance, mobility, requiring assistance walking or using a wheelchair, and history of pneumonia. Variables positively associated with dysphagia identified in Model 2 were Mini-Mental State Examination score, edentulousness, and oral motor assessments score. Conclusions: Cognitive function, dentition, and oral motor function are significant indicators associated with the presence of swallowing in the elderly. When assessing the frail elderly, case file information can help clinicians identify frail elderly individuals who may be suffering from dysphagia.

Neuronavigated high-frequency repetitive transcranial magnetic stimulation for chronic post-stroke dysphagia: A randomized controlled study.

OBJECTIVE: There are potential benefits of repetitive transcranial magnetic stimulation (rTMS) in improving swallowing functions after stroke; however, few studies have been performed in the chronic stroke population. This study aims to distil the key effects of rTMS on swallowing functions and swallowing-related quality of life. METHODS: Twenty-two participants with chronic post-stroke dysphagia were randomly assigned into active or sham rTMS groups. Seven participants withdrew from the study, thus data from 15 participants (mean age 64.6 years) were analysed. Participants received 3,000 pulses of 5 Hz rTMS (active: n = 11; sham: n = 4) on the tongue area of the motor cortex for 10 days over a period of 2 weeks. All participants were assessed 1 week before, and 2 months, 6 months and 12 months after stimulation. Outcomes were measured by a videofluoroscopic swallowing study, swallowing-related quality-of-life questionnaire and Iowa Oral Performance Instrument. RESULTS: No statistically significant effects were identified for any outcome measures. CONCLUSION: This study indicates that 5 Hz rTMS applied over the tongue area of the motor cortex is not effective for improving swallowing function in individuals with chronic post-stroke dysphagia. Possible explanations for these non-significant results are dis cussed. Future studies should explore the potential of the current protocol in conjunction with conventional dysphagia therapy.

A systematic review of resonant voice therapy.

PURPOSE: The purpose of this study is to systematically review the literature on resonant voice therapy and to evaluate the level of evidence on the effectiveness of using resonant voice therapy in treating dysphonia. METHOD: Refereed journal papers from 1974 to 2014 were retrieved and reviewed by two independent reviewers using the keywords "Humming, Resonance, Resonant Voice, Semi-occluded or closed tube phonation" using available database systems. Quality of evidence was evaluated by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULT: Thirteen papers met the search criteria. Nine papers were selected by the two reviewers. Two of the papers were randomised-controlled studies and the other seven were observational studies. At least four types of resonant voice therapies were described. They included the Lessac-Madsen Resonant Voice Therapy, Y-Buzz, Resonance Therapy and Humming. The overall level of quality of evidence was graded as "moderate". CONCLUSION: There were limited studies that investigated the effectiveness of resonant voice therapy. Most studies were small-scale uncontrolled observational studies with the inclusion of only small samples or specific populations. There is clearly a need for more large-scale randomised controlled studies with a wider range of populations to provide further evidence on the effectiveness of resonant voice training for different populations.

Is Acupuncture Efficacious for Treating Phonotraumatic Vocal Pathologies? A Randomized Control Trial.

OBJECTIVES: To investigate the effectiveness of acupuncture in treating phonotraumatic vocal fold lesions. STUDY DESIGN/METHODS: A total of 123 dysphonic individuals with benign vocal pathologies were recruited. They were given either genuine acupuncture (n = 40), sham acupuncture (n = 44), or no treatment (n = 39) for 6 weeks (two 30-minute sessions/wk). The genuine acupuncture group received needles puncturing nine voice-related acupoints for 30 minutes, two times a week for 6 weeks, whereas the sham acupuncture group received blunted needles stimulating the skin surface of the nine acupoints for the same frequency and duration. The no-treatment group did not receive any intervention but attended just the assessment sessions. One-hundred seventeen subjects completed the study (genuine acupuncture = 40; sham acupuncture = 43; and no treatment = 34), but only 84 of them had a complete set of vocal functions and quality of life measures (genuine acupuncture = 29; sham acupuncture = 33; and no-treatment = 22) and 42 of them with a complete set of endoscopic data (genuine acupuncture = 16; sham acupuncture = 15; and no treatment = 11). RESULTS: Significant improvement in vocal function, as indicated by the maximum fundamental frequency produced, and also perceived quality of life, were found in both the genuine and sham acupuncture groups, but not in the no-treatment group. Structural (morphological) improvements were, however, only noticed in the genuine acupuncture group, which demonstrated a significant reduction in the size of the vocal fold lesions. CONCLUSIONS: The findings showed that acupuncture of voice-related acupoints could bring about improvement in vocal function and healing of vocal fold lesions.

Wound-healing effect of acupuncture for treating phonotraumatic vocal pathologies: A cytokine study.

OBJECTIVES/HYPOTHESIS: Acupuncture is a less-invasive procedure when compared with surgical treatment for benign vocal pathologies caused by vocal overuse. This study aimed to determine the wound-healing effect of acupuncture in treating phonotraumatic vocal fold lesions. STUDY DESIGN: Two-way, mixed-model, between- and within-subjects, prospective randomized, placebo-controlled, blinded group design. METHODS: Seventeen dysphonic individuals with vocal nodules were recruited from a university clinic in Hong Kong. Each participant was randomly assigned to receive one session of either genuine or sham acupuncture. The genuine acupuncture group (n = 9) received needles puncturing nine voice-related acupoints for 30 minutes, whereas the sham acupuncture group (n = 8) received blunted needles stimulating the skin surface of the nine acupoints for the same frequency and duration. Laryngeal secretions were suctioned from the surface of the vocal folds immediately before, immediately after, and 24 hours after the acupuncture. The protein concentration levels of wound-healing-related cytokines (interleukin [IL]-1ß and IL-10) in these secretion samples were measured. RESULTS: Following acupuncture, a significant increase in the anti-inflammatory cytokine IL-10 was found in the genuine acupuncture group (n = 9) but not in the sham acupuncture group (n = 8). CONCLUSIONS: The findings showed that acupuncture of voice-related acupoints facilitated an anti-inflammatory process in phonotraumatic vocal pathologies. This could be considered as supporting evidence to consider acupuncture as a less-invasive alternative option, when compared to surgery, for treating phonotraumatic vocal pathologies.

Effect of Noise on Vocal Loudness and Pitch in Natural Environments: An Accelerometer (Ambulatory Phonation Monitor) Study.

PURPOSE: This study investigated the effects of environmental noise on the production of vocal intensity and fundamental frequency using an accelerometer. METHODS: Twenty-four vocally healthy young adults (12 men and 12 women, aged 19-22 years) recorded a monologue passage using KayPENTAX (Montvale, NJ, USA) Ambulatory Phonation Monitor (model 3200) under three natural environmental conditions in a randomized order: a quiet room (mean noise, 35.5 dBA), room with moderate level of noise (mean noise, 54.5 dBA), and a room with high noise (mean noise, 67.5 dBA). RESULTS: Both gender groups showed significant increases in the mean vocal intensity, fundamental frequency, and perceived vocal effort in the high-noise environment than in the other two conditions. No significant difference was found in the vocal intensity between the quiet and moderately noisy environment except in the fundamental frequency in the female group. CONCLUSIONS: This study showed that the use of accelerometer for laryngeal signal recordings could be a useful tool for measuring phonation without being affected by the background noise. The findings also support the recommendation that noise levels for conversation should be kept <50-55 dB to maintain speech intelligibility.

Noise levels in an urban Asian school environment.

Background noise is known to adversely affect speech perception and speech recognition. High levels of background noise in school classrooms may affect student learning, especially for those pupils who are learning in a second language. The current study aimed to determine the noise level and teacher speech-to-noise ratio (SNR) in Hong Kong classrooms. Noise level was measured in 146 occupied classrooms in 37 schools, including kindergartens, primary schools, secondary schools and special schools, in Hong Kong. The mean noise levels in occupied kindergarten, primary school, secondary school and special school classrooms all exceeded recommended maximum noise levels, and noise reduction measures were seldom used in classrooms. The measured SNRs were not optimal and could have adverse implications for student learning and teachers' vocal health. Schools in urban Asian environments are advised to consider noise reduction measures in classrooms to better comply with recommended maximum noise levels for classrooms.

Facial bone vibration in resonant voice production.

PURPOSE: This study investigated whether resonant voice training would enhance facial bone vibration during resonant voice production. METHODS: Twelve normal healthy participants undertook four sessions of resonant voice training, each lasted for 30 minutes. Piezoelectric accelerometer was used to measure the vibratory level on the face (nasal bridge and upper lip) and the perilaryngeal area during the production of nasal consonant /m/ and vowels /a/, /i/, and /u/ before and after the resonant voice training. The extents of vibration of these four sounds among these three sites were compared. RESULTS: Significant increase in facial bone vibration following resonant voice training was found. The nasal bridge showed a significantly larger magnitude of increase when compared with that at the upper lip. Different sounds were also found to facilitate different magnitude of facial bone vibration. Greater magnitude of facial bone vibration was found with the phonation of /m/, /i/, and /u/ when compared with the phonation of /a/. CONCLUSION: Resonant voice training facilitated an increase in facial bone vibration, more so at the nasal bridge area than around the upper lip. This is hypothesized to contribute to the improved resonant voice production. Sounds that involve relatively restricted oropharyngeal cavities facilitated a greater extent of facial bone vibration during resonant voice production.

Reliability of laryngostroboscopic evaluation on lesion size and glottal configuration: a revisit.

OBJECTIVES/HYPOTHESIS: This study investigated the inter-rater and intrarater reliability of four basic visual perceptual parameters (lesion size rating and glottal configuration) in laryngostroboscopic evaluation. STUDY DESIGN: Cohort Study. METHODS: Two hundred fifty-five laryngostroboscopic video samples were evaluated by three raters on four measurements: 1) mass lesion size rating, 2) amplitude of vocal fold vibration, 3) supraglottic activity, and 4) shape of the glottal closure using the modified Stroboscopy Examination Rating Form. RESULTS: Good inter- and intrarater reliability were found in rating the lesion size (0.75-0.81, P=.001), anteroposterior supraglottic activity (0.64, P=.001), and glottal closure (0.65, P=.001). Inter-rater reliability in evaluating the mediolateral supraglottic activity and the amplitude of vocal fold vibration were low to moderate (0.50 and 0.46, respectively, P=.001), whereas the intrarater reliability was more variable (0.2-0.70). CONCLUSIONS: The findings indicated that the evaluation of static structures like lesion size rating, the anteroposterior supraglottic compression, and the glottal closure is a relatively reliable method. The evaluation of dynamic structures, such as the vocal fold vibratory amplitude measure was, however, found to be of low reliability. LEVEL OF EVIDENCE: NA.