Laryngeal Airway Resistance Research Articles

A 4-Week Straw Phonation in Water Exercise Program for Aging-Related Vocal Fold Atrophy.

This study evaluated the efficacy of a 4-week straw phonation in water (SPW) exercise program on aging-related vocal fold atrophy (VFA), with a secondary objective to examine the immediate effects of SPW exercises. Thirty-eight older adults aged 60 years and above formally diagnosed with aging-related VFA were randomly assigned into an experimental group undergoing SPW exercises with an 8-cm depth of straw submersion into water for 4 weeks plus vocal hygiene practice (n = 20), and a control group with only vocal hygiene practice (n = 18). Outcome measures included laryngeal endoscopic measures of glottal gap, auditory-perceptual ratings of voice quality, acoustic measures, aerodynamic measures, and standardized self-assessment questionnaire scores. An additional round of acoustic and aerodynamic assessment following 20 min of SPW exercises was conducted to examine the immediate effects. Significant improvements in normalized glottal gap area, perceptual rating of breathiness, smoothed cepstral peak prominence, harmonics-to-noise ratio (HNR), mean oral airflow, subglottal pressure and laryngeal airway resistance at comfortable loudness, Voice-related Quality of Life scores, and Chinese Vocal Fatigue Index Factor 3 scores were observed in the experimental group relative to the control group. There were also significant immediate effects for HNR, mean oral airflow, subglottal pressure, and laryngeal airway resistance. These findings suggested significant immediate improvements in vocal function following SPW exercises, with additional significant improvements in vocal function as well as significant improvements in quality of life following the 4-week SPW exercise program. Further studies with more long-term follow-up are recommended to better understand the efficacy of SPW exercises with deep levels of straw submersion into water as an effective clinical option for the management of hypofunctional dysphonia associated with aging-related VFA.

Effects of a novel, 3D printed bilateral arytenoid abductor on canine laryngeal airway resistance ex vivo

BackgroundLaryngeal paralysis is a disease process most commonly seen in older, large breed dogs. When both arytenoid cartilages are affected dogs can develop life-threatening respiratory compromise, therefore surgical intervention is recommended. While there are multiple surgical procedures that have been described to treat laryngeal paralysis, there remains a considerable risk for postoperative complications, most commonly aspiration pneumonia. The objective of this ex vivo experimental study was to evaluate the effects of a novel, 3D printed bilateral arytenoid abductor on laryngeal airway resistance in canine cadaver larynges. Laryngeal airway resistance was calculated for each specimen before (control) and after placement of a 3D printed, bilateral arytenoid abductor. The airway resistance was measured at an airflow of 10 L/min with the epiglottis closed and at airflows ranging from 15 L/min to 60 L/min with the epiglottis open. The effects of the bilateral arytenoid abductor on laryngeal airway resistance were evaluated statistically.ResultsWith the epiglottis open, median laryngeal airway resistance in all larynges with a bilateral arytenoid abductor were significantly decreased at airflows of 15 L/min (0.0cmH2O/L/sec), 30 L/min (0.2cmH2O/L/sec), and 45 L/min (0.2cmH2O/L/sec) compared to the controls 15 L/min (0.4cmH2O/L/sec; P = 0.04), 30 L/min (0.9cmH2O/L/sec; P = 0.04), and 45 L/min (1.2cmH2O/L/sec; P = 0.04). When the epiglottis was closed, there was no significant difference in laryngeal resistance between the control (18.8cmH2O/L/sec) and the abducted larynges (18.1cmH2O/L/sec; P = 0.83).ConclusionsPlacement of a bilateral arytenoid abductor reduced laryngeal resistance in canine cadaver larynges compared to the controls when the epiglottis was open. With the epiglottis closed, there was no loss of laryngeal resistance while the device abducted the arytenoid cartilages. The results of this ex vivo study is encouraging for consideration of further evaluation of the bilateral arytenoid abductor to determine an appropriate material and tolerance of this device in vivo.

Expiratory Muscle Strength Treatment for Refractory Chronic Cough: A Short-term Single Exercise Program

Patients with chronic cough are some of the most challenging to treat. This preliminary study is the first to examine the effects of a single exercise muscle strength training program to reduce cough severity in patients who failed other treatments. A total of 19 females were included in this study, ranging from age 24 to 80. The maximum phonation time (MPT), laryngeal airway resistance (LAR), maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), Voice Handicap Index-10, (VHI-10) and the Cough Severity Index (CSI) values were obtained pre- and post-treatment. ANOVA two-factor without replication was used to compare values pre- and post-treatment. MIP (Mean of 62.00 to a mean of 78.53) and MEP (Mean of 90.00 to a mean of 112.16) showed significant increase post-treatment. In addition, LAR (Mean of 73.30 to a mean of 60.67) and CSI (Mean of 19.37 to a mean of 15.00) significantly decreased post-treatment. General changes in pre- and post-treatment values were identified with MPT (Mean of 14.89 to a mean of 16.17) and VHI-10 (Mean of 8.00 to a mean of 6.76). A follow-up questionnaire indicated that the majority of patients felt their cough was better after 4 weeks. Muscle strength training provides a tool to aid in the control of cough for patients who are refractory to medical and other behavioral treatments. Improvement in cough may be associated with a reduction in subglottic pressure and increased air flow resulting in lower laryngeal airway resistance.

Examining Relationships Between GRBAS Ratings and Acoustic, Aerodynamic and Patient-Reported Voice Measures in Adults With Voice Disorders

To determine if auditory-perceptual voice ratings performed using the GRBAS scale correlate with acoustic and aerodynamic measures of voice. A secondary aim was to examine the relationship between GRBAS ratings and patient-reported quality of life scales. GRBAS ratings, acoustic, aerodynamic and patient-reported quality of life ratings were collected from the University of Wisconsin Madison Voice and Swallow Outcomes Database for 508 adults with voice disorders. Acoustic measures included noise to harmonic ratio, jitter%, shimmer%, highest fundamental frequency (F0) of vocal range, lowest F0 of vocal range, maximum phonation time and dysphonia severity index. Aerodynamic measures included phonation threshold pressure, subglottal pressure, mean transglottal airflow and laryngeal airway resistance. Patient-reported quality of life measures included the Vocal Handicap Index (VHI) and Glottal Function Index (GFI). GRBAS ratings were significantly correlated with several acoustic and aerodynamic measures, VHI and GFI. The strongest significant correlations for acoustic measures were observed between GRBAS ratings of overall voice quality and perturbation measures (jitter% r = 0.58, shimmer% r = 0.45, noise to harmonic ratio r = 0.36, Dysphonia Severity Index r=-0.56). The strongest significant correlation for aerodynamic voice measures was observed between GRBAS ratings of breathiness and transglottal airflow (r = 0.23), subglottal pressure (r = 0.49), and phonation threshold pressure (r = 0.26). GRBAS ratings were also significantly correlated with both VHI and the GFI scales. R values were higher for the VHI, but remained largely in low range for both scales. Although GRBAS ratings were significantly correlated with multiple objective voice and patient related quality of life ratings, r values were low. These findings support the need for multiple voice measures when performing voice evaluations as no single voice measure was highly correlated with voice quality as measured by the GRBAS scale.

Chronic Refractory Cough: Objective Improvement With Aerodynamic-Focused

Previous investigations have reported that a chronic cough that is refractory to medical therapies improves with behavioral therapies. However, the treatment parameters that may account for improvement in cough symptoms have not yet been objectively documented. The purpose of this study was to document changes in chronic refractory cough using a breath training protocol. The charts of 27 patients with a long-term chronic cough (>6 months) refractory to various medical treatments were reviewed. These patients received 2-4 sessions of breath training therapy over a 6-month period. Treatment sessions consisted of breathing modification exercises such as those reported in the literature. Aerodynamic parameters including mean estimated subglottal air pressure, mean airflow rate, laryngeal airway resistance, and maximum phonation time were obtained before treatment and 6 months after therapy. Patients also completed the Cough Severity Index at the first visit and 6 months after treatment. Twenty four of the 27 patients (M:F = 6:21), with a mean age of 62.4 (range = 28-78, median = 66) had significant Cough Severity Index improvement from 16.74 to 10.04 (P< 0.001) after therapy. Maximum phonation time increased significantly from 12.00 to 16.38 seconds (P= 0.006); mean estimated subglottic air pressure decreased significantly from 7.58 to 6.36 cm H2O (P= 0.004); laryngeal airway resistance decreased significantly from 52.97 to 40.64 ppm (P= 0.013). This investigation provides evidence that patients who followed a protocol that focused on a breath training program reduced their chronic cough. Significant relationships between patient self-assessment of chronic cough and aerodynamic measures of subglottic pressure and glottal airway resistance were found in this group.

Phonation Demonstrates Goal Dependence Under Unique Vocal Intensity and Aerobic Workload Conditions.

Purpose This study investigated whether metabolic respiratory requirements (treadmill workload) affected glottal valving in phonation, based on aerodynamic measures, when a sound pressure level (vocal SPL) is dictated as a target goal. Consistent with a theory of action, we hypothesized that adjustments in glottal valving as measured by laryngeal airway resistance would be dependent upon vocal SPL level, even as workload increased, and loud vocal SPL would interfere more with respiratory homeostasis than spontaneous vocal SPL. Method Thirty-two women enrolled who were ages 18-35 years. A repeated-measures design was used with random assignment of workload and vocal SPL conditions. Aerodynamic and acoustic data were collected during phonation, as were gas volume and concentration data. Analyses were performed with generalized estimating equations. Results Laryngeal airway resistance at a low workload significantly increased when vocal SPL changed from spontaneous to loud. At a loud vocal SPL, laryngeal airway resistance decreased when workload changed from rest to either low or high. Regarding the respiratory system response, minute ventilation increased at a loud vocal SPL when workload changed from rest to either low or high. End-tidal CO2 increased under low and high workloads relative to rest at loud and spontaneous vocal SPLs. Conclusions Mostly consistent with a theory of action, in which motor control is goal dependent (i.e., vocal SPL targets), speakers can achieve a loud vocal SPL despite increases in workload requirements. In contrast, laryngeal airway resistance stays relatively low when vocal SPL occurs spontaneously, suggesting glottal adjustments are made to improve gas exchange as metabolic respiratory requirements become prioritized. Metabolic respiratory requirements appear to be overcome by the overlay of motor control for voicing when a loud vocal SPL is targeted. The implication of goal-dependent phonation for clinicians is that real-world conditions (i.e., loud vocal SPL) matter in vocal testing and voice therapy.

A Comparison of the s/z Ratio to Instrumental Aerodynamic Measures of Phonation

The purpose of this study was to examine how the s/z ratio and instrumental measures of laryngeal valving and voicing efficiency. Prospective, cohort design. Fifteen adult males (mean age 28.3 years) and 15 adult females (mean age 29.2 years) with normal voice quality were recruited and compared on productions of the s/z ratio and instrumental aerodynamic measures. The aerodynamic measures included vital capacity, maximum phonation time, airflow rate during sustained and sentence production, subglottal pressure, and laryngeal airway resistance. These measures were obtained on the Phonatory Aerodynamic System Model 6600. Statistical analyses included a univariate analysis of variance to examine for differences between sexes for all the variables, and between the s/z ratios for each of the three trials. Pearson's Product Moment Correlations were performed to identify the strength and nature of any significant relationships between the s/z ratio and instrumental aerodynamics. There were significant differences in the mean values between males and females only for the measures of vital capacity and maximum phonation time. There were no significant differences between the three trials for the s/z ratio. There was a significant moderate negative correlation between the s/z ratio and laryngeal airway resistance in females and between the s/z ratio and sentence airflow rate in males. The s/z ratio demonstrated only a moderate correlation with limited instrumental measures of laryngeal valving. In the absence of clear evidence of its ability to accurately assess laryngeal valving, the s/z ratio should be used in combination with other instrumental measures of laryngeal aerodynamics for a better representation of aerodynamic functioning.

Biobehavioral Measures of Presbylaryngeus

The objective of this observational study was to assess the relationship between established aging biobehavioral measures and voice decline in normally aging adults. Cross-sectional study. Participants 60-85 years of age were divided into two age and sex-matched groups, based on the presence or absence of presbylaryngeus. Both groups underwent a battery of tests measuring anthropometric variables, inflammatory markers, general health measures, and vocal function parameters. Differences from the norm were calculated for all variables. Parametric and nonparametric tests were performed to assess group differences. In addition, variable selection analysis was performed to determine variables that were most influential in predicting the occurrence of presbylaryngeus in our current sample. Fifty-three participants were divided into age and sex-matched groups of "presbylaryngeus" (n = 26) and "non-presbylaryngeus" (n = 27). The two groups were statistically different in select measures of inflammatory markers, general health measures, and vocal function parameters. Anthropometric measures were not statistically different. Based on variable selection, the variables most predictive of the presence of presbylaryngeus were measures of the Physical Activity Scale of the Elderly, C-reactive protein, laryngeal airway resistance, and vocal roughness. In addition to group differences in vocal function measures, results for the presbylaryngeus group consistently trended sub-optimally on anthropometric measures, two inflammatory markers, and general health measures. These results suggest that this sample of individuals with presbylaryngeus demonstrated greater biobehavioral deficits associated with aging as compared to age and sex-matched non-presbylaryngeus individuals.

Effect of bilateral ventriculocordectomy via ventral laryngotomy on laryngeal airway resistance in larynges of canine cadavers.

OBJECTIVE To evaluate the effect of bilateral ventriculocordectomy via ventral laryngotomy on laryngeal airway resistance (LAR) in canine cadaver larynges. SAMPLE 6 clinically normal canine cadaver larynges. PROCEDURES LAR was determined for each specimen before (baseline) and after bilateral ventriculocordectomy with the epiglottis open and closed. After ventral laryngotomy was performed, the vocal cords were sharply excised, and the incised mucosal edges were apposed with 4-0 glycomer 631 suture in a simple continuous pattern. The thyroid cartilage was apposed with 3-0 polypropylene suture in a simple continuous pattern. RESULTS With the epiglottis closed, baseline median LAR was 27.6 cm H2O/L/s (range, 21.2 to 30.6 cm H2O/L/s), which did not differ significantly from the median LAR after bilateral ventriculocordectomy (24.7 cm H2O/L/s [range, 20.6 to 27.7 cm H2O/L/s]). With the epiglottis open, baseline median LAR was 7.3 cm H2O/L/s (range, 5.4 to 7.8 cm H2O/L/s), which did not differ significantly from the median LAR after bilateral ventriculocordectomy (7.2 cm H2O/L/s [range, 6.6 to 7.6 cm H2O/L/s]). CONCLUSIONS AND CLINICAL RELEVANCE Bilateral ventriculocordectomy did not affect LAR with an open epiglottis in canine cadaver larynges. Therefore, it may not be an effective treatment for laryngeal paralysis. It also did not affect LAR with a closed epiglottis, which may indicate protection against aspiration pneumonia.

Contribution of Glottic Insufficiency to Perceived Breathiness in Classically Trained Singers.

Breathiness in the singing voice is problematic for classical singers. Voice students and singing teachers typically attribute breathiness to breath management issues and breathing technique. The present study sought to determine whether glottic insufficiency may also contribute to breathiness in a singer's voice. Studies have revealed a relationship between insufficient vocal fold closure and inefficiency in the speaking voice. However, the effect of insufficient vocal fold closure on vocal efficiency in singers has yet to be determined. Two groups of voice students identified with and without breathiness issues underwent aerodynamic and acoustic voice assessment as well as laryngeal stroboscopy of the vocal folds to quantify the prevalence of insufficient vocal fold closure, also known as glottic insufficiency. These assessments revealed four groups: 1) those with glottic insufficiency and no perceived voice breathiness; 2) those with glottic sufficiency and perceived voice breathiness; 3) those with glottic insufficiency and perceived breathiness; and 4) those with glottic sufficiency and no perceived breathiness. Results suggest that previously undiscovered glottal insufficiency is common in young singers, particularly women, though the correlation with identified breathiness was not statistically significant. Acoustic and aerodynamic measures including noise-to-harmonics ratio, maximum phonation time, airflow rate, subglottal pressure, and laryngeal airway resistance were most sensitive to glottic insufficiency.

Aerodynamic Outcomes of Four Common Voice Disorders: Moving Toward Disorder-Specific Assessment

The two goals of the present study were to (1) determine the ability of commonly used aerodynamic voice measures to capture change as a function of known interventions and (2) determine if certain aerodynamic measures demonstrate better responsiveness to change in specific disorder types than others. This is a retrospective, longitudinal, single-blinded, cross-sectional study. Patients (n = 70) with a single voice disorder diagnosis of benign vocal fold lesions (lesions), unilateral vocal fold paralysis (UVFP), primary muscle tension dysphonia (MTD-1), or vocal fold atrophy (atrophy) underwent baseline testing, a single intervention (phonosurgery or voice therapy), and follow-up testing. Common aerodynamic measurements were completed in repeated syllables and an all-voiced sentence. Statistically significant improvements were observed for two outcome measures, average airflow in syllables, and average airflow in the all-voiced sentence. Patients with lesions, UVFP, and MTD-1 improved in average airflow in the all-voiced sentence. Patients with UVFP also improved in airflow in syllables. Average airflow in the all-voiced sentence changed as a function of treatment for the lesion, MTD-1, and UVFP groups, demonstrating a disorder-specific pattern. Laryngeal airway resistance, and estimates of average subglottal pressure did not show significant change. Average airflow in the all-voiced sentence measurements is recommended as a routine voice measure, and further investigation of other aerodynamic measures' sensitivity to change is warranted.

The Effects of Hyper- and Hypocapnia on Phonatory Laryngeal Airway Resistance in Women.

The larynx has a dual role in the regulation of gas flow into and out of the lungs while also establishing resistance required for vocal fold vibration. This study assessed reciprocal relations between phonatory functions-specifically, phonatory laryngeal airway resistance (Rlaw)-and respiratory homeostasis during states of ventilatory gas perturbations. Twenty-four healthy women performed phonatory tasks while exposed to induced hypercapnia (high CO2), hypocapnia (low CO2), and normal breathing (eupnea). Effects of gas perturbations on Rlaw were investigated as were the reciprocal effects of Rlaw modulations on respiratory homeostasis. Rlaw remained stable despite manipulations of inspired gas concentrations. In contrast, end-tidal CO2 levels increased significantly during all phonatory tasks. Thus, for the conditions tested, Rlaw did not adjust to accommodate ventilatory needs as predicted. Rather, stable Rlaw was spontaneously accomplished at the cost of those needs. Findings provide support for a theory of regulation wherein Rlaw may be a control parameter in phonation. Results also provide insight into the influence of phonation on respiration. The work sets the foundation for future studies on laryngeal function during phonation in individuals with lower airway disease and other patient populations.

Laryngeal aerodynamic analysis of vocal nodules

The present study is aimed to investigate the effects of vocal nodules on the aerodynamic analysis of the voice. The study included twelve females with normal laryngeal and respiratory functions and twelve age, gender and language matched females with bilateral vocal nodules within the age group of 18-40 years. All participants were subjected to non-invasive aerodynamic analysis using Aeroview 1.4.4 version (Glottal Enterprises Inc, USA). The participants were instructed to produce the CV syllable train papapapa into the circumvented mask at comfortable pitch and loudness. The recorded stimuli were analyzed to obtain laryngeal aerodynamic measures such as estimated subglottic pressure, mean airflow rate, laryngeal airway resistance, and laryngeal airway conductance. Mean and standard deviation for all the four laryngeal aerodynamic measures were calculated separately for both control and clinical groups. The results revealed significant effect of voice on laryngeal measures such as estimated subglottic pressure and mean airflow rate. Thus, results suggest that indirect measurement of laryngeal aerodynamic parameters are effective and essential investigative tools in assessment of vocal nodules.

Evaluation of Auditory and Visual Feedback for Airflow Interruption

Clinical application of mechanical interruption methods for measuring aerodynamic parameters has been hindered by relatively high intrasubject variability. To improve the intrasubject reliability, we evaluated the effect of auditory and visual feedback on subject performance when measuring aerodynamic parameters with the airflow interrupter. Eleven subjects performed four sets of 10 trials with the airflow interrupter: no feedback (control); auditory feedback (tone matching subject's F0 played over headphones); visual feedback (real-time feedback of sound pressure level, frequency, and airflow); and combined auditory and visual feedback. Task order was varied across subjects. The effect of each feedback method on mean and coefficient of variation (CV) of subglottal pressure (Ps), mean flow rate (MFR), and laryngeal airway resistance (RL; Ps/MFR) compared with that of the control trials was determined using paired t tests. Feedback methods were compared against each other using one-way repeated measures analysis of variance. Each feedback method significantly decreased CV of RL compared with that of the control trials (auditory feedback: P=0.005; visual feedback: P=0.008; and combined feedback: P<0.001). Auditory feedback (P=0.011) and combined feedback (P=0.026) also decreased CV of MFR. Mean MFR was significantly higher during trials with visual feedback compared with that of the auditory feedback. Each feedback method improved the intrasubject consistency when measuring RL. Feedback appeared to have a greater effect on MFR than Ps. Although there is no clear optimal feedback method, each is preferable to not providing any feedback during trials. Evaluating new methods of visual feedback to further improve MFR and thus RL measurement would be valuable.

Treatment of laryngeal hyperfunction with flow phonation: A pilot study

Context: While clinical successes and descriptions have been reported in a few texts, no data exist to define the utility of flow phonation to improve voice quality in patients with laryngeal hyperfunction. Aims: To provide pilot data regarding the utility of three exercises (gargling, cup bubble blowing, and stretch-and-flow) to improve phonatory airflow during voicing in patients with laryngeal hyperfunction. Settings and Design: Outpatient Voice and Swallowing Center in a University Medical Center. Materials and Methods: Participants received five treatment sessions and were evaluated prior to treatment and after each session using a Phonatory Aerodynamic System to measure airflow during voicing tasks. Noise-to-harmonic ratio and perceptual voice measures were also obtained, as was self-perception of voice handicap. Statistical Analysis Used: Repeated All increased airflow and decreased laryngeal airway resistance over five sessions. Measures Analysis of Variance. Results: Six participants completed the protocol. All participants decreased self-perception of voice handicap and improved on noise-to-harmonic ratio and perceptual ratings of vocal quality. Conclusions: Data derived on a small sample of patients in an exploratory investigation suggest further research into the use of these three exercises to improve airflow with voicing and improve vocal quality in patients with laryngeal hyperfunction is warranted.

The effects of cigarette smoking on the female voice

To investigate voice changes as they develop over time due to cigarette smoking, women who never smoked (NS), women who smoked less than 10 years (S1), and women who smoked 10 or more years (S2) were compared. Acoustic (fundamental frequency, jitter, shimmer, signal-to-noise ratio), electroglottographic (open, closing, and speed quotients), aerodynamic (subglottal pressure, airflow, laryngeal airway resistance), and perceptual measures were obtained. Fundamental frequency and open quotient significantly decreased and speed quotient significantly increased in S1 and S2; jitter and shimmer significantly increased in S2 only. NS were perceived as non-smokers more reliably than S1 and S2 as smokers. Fundamental frequency, open quotient, and speed quotient were the most sensitive indicators of smoking effects on the female voice.

Assessment of Phonation Threshold Pressure: A Critical Review and Clinical Implications

To describe the origins of the task elicitation procedure for determining phonation threshold pressure and, through a literature review and online survey, describe published procedural, environmental, and participant variable departures from the original methodology. Literature search terms included phonation threshold pressure, subglottal pressure and phonation, pressure measurement and phonation, lung pressure and phonation, and vocal fold oscillation onset. Inclusion criteria were limited to indirect assessment of phonation threshold pressure, English language publications between 1980 and 2009, and peer-reviewed journals. Studies including animals, computer or physical models, alaryngeal speakers, laryngeal airway resistance, or any airflow interruption technique were excluded. Twenty-four articles matched the inclusionary criteria. An online survey to query task elicitation procedures was then developed from the literature review. The scientific rationale for inclusion of phonation threshold pressure data was consistent across published studies; however, variations in procedural methodology for task elicitation were identified, as were environmental and participant inconsistencies that might affect phonation threshold pressure values. Findings of the online survey mirrored the inconsistencies identified in the literature review. The methodological differences for task elicitation identified in this comprehensive review of the literature and the online survey, while bringing into question the reliability of phonation threshold pressure measurement, illuminate scientific questions yet to be answered to further refine and potentially standardize phonation threshold pressure as a more reliable research and clinical measurement.

Aerodynamic Evaluation of the Postthyroidectomy Voice

Changes in vocal function before and after thyroidectomy were examined using aerodynamic and related assessments. Laryngeal airway resistance (R(law)) and phonation threshold pressure (PTP) were hypothesized to be sensitive to changes in laryngeal function that may occur after thyroidectomy separate from changes that may occur from endotracheal intubation alone. Prospective longitudinal clinical trial with comparison group. Eighty patients were evaluated preoperatively, and 2 weeks and 3 months postoperatively to assess voice outcomes after thyroidectomy. In addition, 16 patients who underwent a nonneck operation were tested as a control group. Maximum phonation time (MPT), mean airflow, R(law), and PTP were determined at two vocal fundamental frequency (F0) levels (30% and 80% of the F0 range). No systematic differences were detected for MPT, mean airflow, or R(law) as a short-term or intermediate-term outcome of either surgical group. PTP decreased significantly over time for both groups of participants and at both F0 levels. F0 range decreased significantly at the short-term postsurgical assessment and covaried with the PTP results, thereby explaining some of the variability in the PTP data. Aerodynamic assessment did not reveal systematic changes in vocal function associated with thyroidectomy, although PTP decreased postoperatively for both surgical groups. This may be attributable in part to a learning effect or to postoperative reductions in F0 range.

Do Obesity and Weight Loss Affect Vocal Function?

Obesity may be associated with increased tissue bulk in the laryngeal airway, neck, and chest wall, and as such may affect vocal function. Eight obese and eight nonobese adults participated in this study; the obese participants underwent bariatric surgical procedures. This mixed-design study included cross-sectional analysis for group differences and longitudinal analysis for multidimensional changes in vocal function from four assessments collected over 6 months. No significant differences were detected between groups from the preoperative assessment. Further, no changes were detected over time for acoustic parameters, maximum phonation time, laryngeal airway resistance, and airflow during a sustained vowel for either group. Only minor differences were detected for strain, pitch, and loudness perceptions of voice over time, but not between groups. Phonation threshold pressure (PTP), at comfortable and high pitches (30% and 80% of the F0 range) changed significantly over time, but not between groups. Examination of individual data revealed a trend for PTP at 30% F0 to decrease as body mass index decreased. PTP may be informative for assessing vocal function in clients who present with obesity and voice symptoms.

Laryngeal aerodynamics associated with oral contraceptive use: Preliminary findings

The purpose of this study was to examine possible differences in laryngeal aerodynamic measures during connected speech associated with oral contraceptive (OC) use. Eight women taking an OC, and eight others not taking an OC, participated in the study. Three trials of syllable /p ▪/repetitions were obtained using a circumferentially vented face mask and small translabial tube. All participants were recorded on or near days 7 and 14 of their menstrual cycle. Subglottal pressure ( P SG) and average airflow rates were obtained to determine laryngeal airway resistance. Glottal airflow measures of peak flow, minimum flow, alternating flow, as well as relative sound level (RSL) were obtained. P SG was obtained from the pressure peak associated with/p/. All airflow parameters and RSL were obtained from the vowel portion. No significant differences were found related to day of recording or OC use, indicating that OC use does not significantly affect laryngeal airflow regulation. Learning outcomes The reader will better understand the effects of hormones and oral contraceptives on the female voice, as well as the specific changes in vocal function that may occur in conjunction with the use of oral contraceptives.