Vocal Ergonomics in the Workplace: Heating, Ventilation, and Air-Conditioning Method Influences on Vocal Comfort and Function

2017 ◽  
Vol 60 (2) ◽  
pp. 355-363 ◽  
Author(s):  
Mary J. Sandage ◽  
Keith A. Rahn ◽  
Audrey G. Smith

Purpose The purpose of this study was to examine the influence of the heating, ventilation, and air-conditioning method on voice function following a voicing task using ecologically valid offices, one with radiant HVAC and one with forced air. Method A total of 12 consented participants (6 women, 6 men) narrated a video in each of 4 environmental conditions in a within-between repeated-measures design. Acoustic data were collected with an ambulatory phonation monitor and perceived phonatory effort was determined following the voicing task. Data were analyzed using a within-between repeated-measures analysis of variance with significance set at α < .05. Results Perceived phonatory effort did not differ between environments; however, a significant difference in vocal amplitude between 2 trials was identified for the male participants and physiologically significant differences in vocal amplitude were identified for male and female participants. Conclusions The findings suggest that perceived phonatory effort may not be a sensitive measure of vocal function differences following a voicing task in ecologically valid office spaces despite significant acoustic findings. Future research should address longer exposure to environmental differences combined with a longer voicing task within ecologically valid work spaces as well as the recruitment of participants who have particular vulnerability to environmental perturbations.

2014 ◽  
Vol 57 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Mary J. Sandage ◽  
Nadine P. Connor ◽  
David D. Pascoe

Purpose Phonation threshold pressure and perceived phonatory effort were hypothesized to increase and upper airway temperature to decrease following exposure to cold and/or dry air. Greater changes were expected with mouth versus nose breathing. Method In a within-participant repeated measures design, 15 consented participants (7 men, 8 women) completed 20-min duration trials to allow for adequate thermal equilibration for both nose and mouth breathing in 5 different environments: 3 temperatures (°C) matched for relative humidity (% RH), cold (15 °C, 40% RH), thermally neutral (25 °C, 40% RH), and hot (35 °C, 40% RH); and 2 temperatures with variable relative humidity to match vapor pressure for the neutral environment (25 °C, 40% RH), cold (15 °C, 74% RH) and hot (35 °C, 23% RH). Following each equilibration trial, measures were taken in this order: upper airway temperature (transnasal thermistor probe), phonation threshold pressure, and perceived phonatory effort. Results Data were analyzed using repeated measures analysis of variance, and no significant differences were established. Conclusions The study hypotheses were not supported. Findings suggest that the upper airway is tightly regulated for temperature when challenged by a realistic range of temperature and relative humidity environments. This is the first study of its kind to include measurement of upper airway temperature in conjunction with measures of vocal function.


Methodology ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pablo Livacic-Rojas ◽  
Guillermo Vallejo ◽  
Paula Fernández ◽  
Ellián Tuero-Herrero

Abstract. Low precision of the inferences of data analyzed with univariate or multivariate models of the Analysis of Variance (ANOVA) in repeated-measures design is associated to the absence of normality distribution of data, nonspherical covariance structures and free variation of the variance and covariance, the lack of knowledge of the error structure underlying the data, and the wrong choice of covariance structure from different selectors. In this study, levels of statistical power presented the Modified Brown Forsythe (MBF) and two procedures with the Mixed-Model Approaches (the Akaike’s Criterion, the Correctly Identified Model [CIM]) are compared. The data were analyzed using Monte Carlo simulation method with the statistical package SAS 9.2, a split-plot design, and considering six manipulated variables. The results show that the procedures exhibit high statistical power levels for within and interactional effects, and moderate and low levels for the between-groups effects under the different conditions analyzed. For the latter, only the Modified Brown Forsythe shows high level of power mainly for groups with 30 cases and Unstructured (UN) and Autoregressive Heterogeneity (ARH) matrices. For this reason, we recommend using this procedure since it exhibits higher levels of power for all effects and does not require a matrix type that underlies the structure of the data. Future research needs to be done in order to compare the power with corrected selectors using single-level and multilevel designs for fixed and random effects.


2010 ◽  
Vol 21 (04) ◽  
pp. 249-266 ◽  
Author(s):  
Lynzee N. Alworth ◽  
Patrick N. Plyler ◽  
Monika Bertges Reber ◽  
Patti M. Johnstone

Background: Open canal hearing instruments differ in method of sound delivery to the ear canal, distance between the microphone and the receiver, and physical size of the devices. Moreover, RITA (receiver in the aid) and RITE (receiver in the ear) hearing instruments may also differ in terms of retention and comfort as well as ease of use and care for certain individuals. What remains unclear, however, is if any or all of the abovementioned factors contribute to hearing aid outcome. Purpose: To determine the effect of receiver location on performance and/or preference of listeners using open canal hearing instruments. Research Design: An experimental study in which subjects were exposed to a repeated measures design. Study Sample: Twenty-five adult listeners with mild sloping to moderately severe sensorineural hearing loss (mean age 67 yr). Data Collection and Analysis: Participants completed two six-week trial periods for each device type. Probe microphone, objective, and subjective measures (quiet, noise) were conducted unaided and aided at the end of each trial period. Results: Occlusion effect results were not significantly different between the RITA and RITE instruments; however, frequency range was extended in the RITE instruments, resulting in significantly greater maximum gain for the RITE instruments than the RITA instruments at 4000 and 6000 Hz. Objective performance in quiet or in noise was unaffected by receiver location. Subjective measures revealed significantly greater satisfaction ratings for the RITE than for the RITA instruments. Similarly, preference in quiet and overall preference were significantly greater for the RITE than for the RITA instruments. Conclusions: Although no occlusion differences were noted between instruments, the RITE did demonstrate a significant difference in reserve gain before feedback at 4000 and 6000 Hz. Objectively; no positive benefit was noted between unaided and aided conditions on speech recognition tests. These results suggest that such testing may not be sensitive enough to determine aided benefit with open canal instruments. However, the subjective measures (Abbreviated Profile of Hearing Aid Benefit [APHAB] and subjective ratings) did indicate aided benefit for both instruments when compared to unaided. This further suggests the clinical importance of subjective measures as a way to measure aided benefit of open-fit devices.


2019 ◽  
Vol 15 (1) ◽  
pp. 53-59
Author(s):  
Dave Elliott ◽  
Dayne Massey

There are many studies showing acute static stretching to be detrimental to power generation. However, the majority have focused upon the impact of stretching the agonist musculature. To date, few have examined the potential benefits of acute antagonist static stretching; none have focused on upper-body power. Utilising a repeated-measures design, 30 male participants were randomly assigned to one of two groups whereupon they performed four bench-throw tests; two control (NO-STRETCH) and two experimental (STRETCH), in a counter-balanced manner. Prior to the experimental measures, participants undertook a series of static antagonist stretches. Mean Pmax (SD) in the NO-STRETCH trials was 862.76 (146)W and 898.50 (144)W, respectively. For STRETCH trial 1, Pmax = 930.10 (146)W and trial 2, Pmax = 953.36 (136)W. When compared to the respective NO-STRETCH trials, antagonist static stretching did have a significant effect on Pmax for both the initial ( P < 0.01, d = 1.33) and the re-stretching procedures ( P < 0.01, d = 1.35). A significant difference was also found between the STRETCH trials ( P < 0.01, d = 0.46). The results have practical implications for those involved in upper-body power activities. Specifically, incorporating upper-body antagonist static stretching into pre-performance routines might offer a simple and effective means of enhancing agonist power.


Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3145 ◽  
Author(s):  
Dylan T. Wilburn ◽  
Steven B. Machek ◽  
Thomas D. Cardaci ◽  
Darryn S. Willoughby

Research has suggested that nutrient, exercise, and metabolism-related proteins interact to regulate mammalian target of rapamycin complex one (mTOR) post-exercise and their interactions needs clarification. In a double-blind, cross-over, repeated measures design, ten participants completed four sets to failure at 70% of 1-repitition maximum (1-RM) with 45 s rest on angled leg press with or without pre-exercise maltodextrin (2 g/kg) after a 3 h fast. Vastus lateralis biopsies were collected at baseline before supplementation and 1 h post-exercise to analyze Focal Adhesion Kinase (FAK), ribosomal protein S6 kinase beta-1 (p70S6K), insulin receptor substrate 1 (IRS-1), phosphatidylinositol 3-kinase (PI3K), and 5′ AMP-activated protein kinase (AMPK) activation. FAK and IRS-1 activity were only elevated 1 h post-exercise with carbohydrate ingestion (p < 0.05). PI3K and p70S6K activation were both elevated after exercise in both conditions (p < 0.05). However, AMPK activity did not change from baseline in both conditions (p > 0.05). We conclude that FAK does not induce mTOR activation through PI3K crosstalk in response to exercise alone. In addition, FAK may not be regulated by AMPK catalytic activity, but this needs further research. Interestingly, carbohydrate-induced insulin signaling appears to activate FAK at the level of IRS-1 but did not enhance mTOR activity 1 h post-exercise greater than the placebo condition. Future research should investigate these interactions under different conditions and within different time frames to clearly understand the interactions between these signaling molecules.


2012 ◽  
Vol 92 (5) ◽  
pp. 707-717 ◽  
Author(s):  
Debbie J. Silkwood-Sherer ◽  
Clyde B. Killian ◽  
Toby M. Long ◽  
Kathy S. Martin

Background Clinical observations have suggested that hippotherapy may be an effective strategy for habilitating balance deficits in children with movement disorders. However, there is limited research to support this notion. Objective The purposes of this study were to assess the effectiveness of hippotherapy for the management of postural instability in children with mild to moderate balance problems and to determine whether there is a correlation between balance and function. Design A repeated-measures design for a cohort of children with documented balance deficits was used. Methods Sixteen children (9 boys and 7 girls) who were 5 to 16 years of age and had documented balance problems participated in this study. Intervention consisted of 45-minute hippotherapy sessions twice per week for 6 weeks. Two baseline assessments and 1 postintervention assessment of balance, as measured with the Pediatric Balance Scale (PBS), and of function, as measured with the Activities Scale for Kids—Performance (ASKp), were performed. Results With the Friedman analysis of variance, the PBS and the ASKp were found to be statistically significant across all measurements (P&lt;.0001 for both measures). Post hoc analysis revealed a statistical difference between baseline and postintervention measures (P≤.017). This degree of difference resulted in large effect sizes for PBS (d=1.59) and ASKp (d=1.51) scores after hippotherapy. A Spearman rho correlation of .700 indicated a statistical association between PBS and ASKp postintervention scores (P=.003). There was no correlation between the change in PBS scores and the change in ASKp scores (rs=.13, P&gt;.05). Limitations Lack of a control group and the short duration between baseline assessments are study limitations. Conclusions The findings suggest that hippotherapy may be a viable strategy for reducing balance deficits and improving the performance of daily life skills in children with mild to moderate balance problems.


2013 ◽  
Vol 24 (07) ◽  
pp. 600-606 ◽  
Author(s):  
Alexandra C. Huebner ◽  
Susan R. Lytle ◽  
Steven M. Doettl ◽  
Patrick N. Plyler ◽  
James T. Thelin

Background: Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo in adults and is a result of otolithic particles or debris that become free floating within a semicircular canal or adhere to the cupula. Characteristics of BPPV include brief episodes of latent onset vertigo that occur with changes in head position, transient rotary nystagmus beating toward the dependent ear, and reversed nystagmus upon sitting up. Both the vertigo and nystagmus fatigue quickly while maintaining the same head position. The BPPV may be classified as objective or subjective. Objective BPPV presents all the aforementioned symptoms whereas subjective BPPV presents all the symptoms without nystagmus. The accepted method of treatment for objective BPPV is canalith repositioning maneuvers (CRM); however, CRM are not traditionally used as the method of treatment for cases of subjective BPPV. Purpose: The purpose of the study was to determine if the subjective report of dizziness using the Dizziness Handicap Inventory (DHI) was different in patients with objective and subjective BPPV and to determine if the two groups showed similar improvements in perceived dizziness handicap following CRM treatment. Research Design: The present study utilized a retrospective, repeated measures design. Study Sample: Sixty-three adults with BPPV that were given the DHI both before and after CRM treatment. Data Collection and Analysis: Pre and post DHI results were analyzed for participants with objective versus subjective BPPV. A five-question DHI subscale was also analyzed between the groups. Results: A significant difference was noted between initial and posttreatment DHI scores for patients in both the subjective and objective groups when using the full-scale and subscale DHI. No significant difference was noted between groups for their initial or posttreatment DHI scores. The two groups also did not differ significantly in their initial or posttreatment DHI subscale scores. Conclusions: The results of the study indicated that individuals with both objective and subjective BPPV demonstrated significant improvement in DHI scores following CRM treatment. Additionally, there was no difference in DHI improvement for the subjective versus objective group suggesting CRM are effective for both subjective BPPV and objective BPPV. This improvement in DHI scores was also noted in the five-question DHI subscale with no significant difference noted between groups. These findings combined with previous studies suggest the presence or absence of nystagmus during Dix-Hallpike maneuvers is not related to the effectiveness of treatment using CRM.


2021 ◽  
Author(s):  
Peter Sutton ◽  
Marie Ohlsson ◽  
Ulrik Röijezon

Abstract Background: Assessment of shoulder proprioception outside the laboratory in the absence of specialized equipment remains a challenge with field-based tests often lacking good reliability, validity and feasibility. This study aimed to enhance the knowledge base surrounding the assessment of shoulder proprioception and investigated the effect of fatigue on shoulder joint position sense (JPS) amongst amateur male handball players.Method: 27 healthy recreationally active participants and 13 amateur male handball players undertook two sessions of active JPS tests using laser pen technology and a calibrated 2-dimensional target to assess test-retest reliability. The active JPS test was then utilized on the subgroup of handball players who were subjected to five bouts of a repeated throwing task in order to investigate the effect of local fatigue on shoulder JPS. Results: The intraclass correlation coefficient for the active JPS test was 0.78 (95% CI = [0.57; 0.89]). Standard error of measurement between trials was 0.70° (range 0.57°-0.90°). For the throwing task, repeated measures analysis of variance revealed a significant interaction for arm x bout (F5=2.74, p=0.028) and a significant effect for arm (F1=5.85, p=0.034). Post hoc analysis showed a significant difference between throwing arm and non-throwing arm after throwing bout one (p=0.036), three (p=0.026) and four (p=0.041). Conclusion: Assessment of the active JPS test showed acceptable reliability and measurement error. Repeated throwing to fatigue decreased shoulder JPS in amateur male handball players which indicate validity of the test to identify reduced proprioception.


2021 ◽  
Vol 9 (9) ◽  
pp. 232596712110266
Author(s):  
Gretchen D. Oliver ◽  
Jessica L. Downs Talmage ◽  
Kenzie B. Friesen ◽  
Michael G. Saper ◽  
Jeffrey R. Dugas

Background: Baseball leagues have implemented pitch count and pitch type restrictions based on biomechanical concepts associated with pitch type. Softball has not yet adopted these practices, although softball pitchers continue to pitch at a high volume and learn multiple pitches at a young age. Purpose: To examine shoulder and elbow kinetics between the fastball, curveball, and changeup, as well as to provide descriptive upper extremity pain data in National Collegiate Athletic Association (NCAA) softball pitchers. Study Design: Descriptive laboratory study. Methods: Study participants consisted of 27 female NCAA Division I softball pitchers (age, 20.2 ± 1.9 years; height, 175.7 ± 5.7 cm; weight, 83.6 ± 12.7 kg). The participants pitched 3 balls of each pitch type, and kinetic data were recorded. A one-way within-participants repeated-measures multivariate analysis of variance was used to determine significant differences in kinetics and pitch speed between pitch types. Results: Results revealed a statistically significant main effect for pitch type (Wilks λ = .087; F = 36.523; P < .001). Post hoc testing showed that the changeup produced less anterior elbow force compared with the fastball ( P < .001) and the curveball ( P = .012). In addition, the changeup produced less shoulder distraction force compared with the fastball ( P < .001) and the curveball ( P = .001). Additionally, there was a significant difference in pitch speed between all 3 pitch types ( P = .006). The curveball revealed no statistically significant kinetic differences compared with the fastball. Conclusion: The fastball and curveball placed similar stress on the upper extremity in collegiate softball pitchers. However, in comparison with the changeup, the fastball and curveball placed increased stress on the upper extremity. More research is needed to fully explain the differences seen between pitch type and injury risk. Clinical Relevance: Sports medicine professionals, coaches, and athletes should use the current study results to note these differences in shoulder distraction and elbow anterior forces between softball pitch types. The study results can be used as a reference and basis for future research investigating kinetic differences across varying pitch types.


Author(s):  
Josiane Mukagihana ◽  
Florien Nsanganwimana ◽  
Catherine M. Aurah

Linking motivation and learning is central to understanding students’ motivation toward learning and learning itself as complex cognitive phenomena. Some studies focused on students’ motivation toward learning biology in general; however, the shortage of studies on the effect of animation-based instruction and small-group laboratory activities as Resource-based Instructions (RBIs) on pre-service biology teachers was realized. The present study aimed to determine the effect of resource-based Instructions on pre-service biology teachers’ academic motivation toward learning biology at private and public Universities in Rwanda. Pre-service biology teachers were grouped into three groups at a public teacher traning University and received a pre-and post-assessment.  Quasi-experimental, pre and post-test control group design was used at a public university, while a repeated measures design was used at a private university. The standard academic motivation scale for learning biology (AMSLB) yielded a Cronbach alpha coefficient of 0.71 before use. The t-Test was computed to measure the statistically significant difference between the pre-and post-assessment scores and group of RBI interventions. Multivariate analysis (MANOVA) was computed to measure the effect of RBIs vis à vis the AMSLB factors. Findings revealed no statistically significant difference (df=18, p=.458) in the motivation of learning biology of pre-service teachers before and after learning via traditional instruction at a public university. However, a statistically signficant difference was found with animation instruction (df=18, p=.002) and lab instruction (df=18, p=.014).  The motivation of learning biology increased at a public university than at a private university. However, animations and small-group lab activities increased pre-service biology teachers’ intrinsic and extrinsic—career motivation of learning biology at both universities. Therefore, the study recommends using RBIs to improve pre-service biology teachers’ motivation toward learning biology.


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