Comparing nebulized water versus saline after laryngeal desiccation challenge in Sjögren's Syndrome

The Effect of Laryngeal Dehydration and Nebulized Osmotic Agents on the Voice

OBJECTIVE

This study investigates the effects of dehydration induced by dry air breathing and the nebulization of various osmotic agents on vocal parameters, including perceptual, acoustic, and electroglottographic measures.

METHODS

Thirty normophonic females (age x̅ = 26, SD = 1.67) participated over three consecutive days. On the first day, the baseline data were meticulously collected before the participants underwent a 22-minute session of transoral dry air breathing. Immediately after this desiccation protocol, measurements were taken to establish the initial effects. Subsequently, one of three osmotic agents was randomly selected for each participant. These agents included hypotonic distilled water, 0.9% isotonic saline, and 3% hypertonic saline. Each participant then underwent a 10-minute nebulization session with 5 mL of the assigned osmotic agent. The process was repeated on the second and third days. Each day, the participants again experienced the 22-minute transoral dry air breathing session. The evaluations were performed by Borg CR-10 (perceived vocal effort), electroglottography (EGG), voice onset time (VOT), nasalance score (NS), and cepstral peak prominence analyses with CAPE-V sentences (s).

RESULTS

No statistically significant differences were found in the EGG parameters between the preliminary recordings, post transoral medical-grade dry air protocol, and after each of task-hypotonic, task-isotonic, and task-hypertonic. Following the transoral medical-grade dry air protocol, both /s1/-CPP and /s5/-CPP values decreased compared with the preliminary recordings. Only /s1/-CPP values increased after the 0.9% isotonic saline nebulization. NS from preliminary measurements was higher for both oronasal and nasal texts compared with scores after the dry air protocol and nebulization. Voiceless plosive VOT values decreased solely after the 0.9% isotonic saline nebulization. Participants' Borg CR-10 scores increased after transoral medical-grade dry air protocol and decreased after nebulization with distilled water and 0.9% isotonic saline.

CONCLUSIONS

Isotonic saline and distilled water nebulization protocols demonstrated a trend toward mitigating the adverse effects of the transoral medical-grade dry air inhalation protocol on vocal parameters.

Thermal, Acoustic, and Self-Perceptual Measures of Pre-Post Vocal Change After Surface Hydration in Speech-Language Pathologists

PURPOSE

Numerous clinical findings support the idea that increased surface laryngeal hydration prevents and manages voice problems in professional voice users. However, empirical evidence for surface laryngeal hydration (nebulized saline solution) through multidimensional voice measures is lacking, especially in speech-language pathologists (SLPs). Hence, the present study investigated the effect of surface hydration using nebulized saline solution on voice quality using thermal, acoustic, and self-perceptual measures in SLPs.

METHODS

The study involved 30 SLPs divided into three groups: group I had no voice usage, group II read aloud passage for 1 hour without surface hydration, and group III read aloud passage for 1 hour with surface hydration for 10 minutes. Multidimensional voice outcomes such as thermal (front, right, and left view of the throat), acoustic (Multidimensional Voice Program), and self-perceptual (perceived phonatory effort, perceived vocal tiredness) were measured for the pretest and post test condition in all the group.

RESULTS

Pre-post comparison shows that thermal measures showed a significant increase in group II and a significant decrease in group III. Also, fundamental frequency, perturbation, and self-perceptual measures showed a significant increase in group II compared to group III. Further, the between-group post test comparisons revealed a significant decrease in many outcome measures in group III compared to group II. The above results support that surface hydration significantly influenced the voice quality during the vocal loading task.

CONCLUSION

The study confirms the benefits of surface hydration using saline solution in SLPs. Surface hydration preserves vocal quality compared to those not hydrated during vocal loading.

Volitional and Non-volitional Devices Used in Voice Therapy and Training: A Scoping Review-Part A

OBJECTIVE

To map the volitional and non-volitional devices used by speech and language pathologists (SLPs) in voice training and therapy and characterize their use in research on voice interventions.

METHODS

This scoping review is the first part of a larger study. The electronic search was carried out by mapping the references in PubMed/Medline, LILACS/BVS, Scopus, Web of Science, EMBASE, and the Cochrane Library, and the manual search was carried out in the grey literature. Two blind independent reviewers selected and extracted data; divergences were solved by consensus. The data extracted in this part of the study were the authorship and year of publication, country, study design, sample characteristics, intervention modality, ingredient, target, mechanism of action, dosage, and outcome measures. They were addressed with descriptive analysis.

RESULTS

Publications that use devices as ingredients are mostly from the last two decades, mainly carried out in the United States of America and Brazil, in adults of both sexes with behavioral dysphonia. Forty-two types of devices were used, many of them with similar approaches but different nomenclatures. Most devices were used voluntarily, focusing on vocal function, and aiming to increase source and filter interaction. Most studies used silicone tubes. The most reported technical specification to apply the ingredient was surface electrodes on the neck. Device dosage was time-controlled, and the most used outcomes were self-assessment and acoustic analysis.

CONCLUSION

Devices are currently used as ingredients in vocal interventions, with a greater focus on increasing the source and filter interaction, associated with silicone tubes (the most used devices in these studies), which have been dosed with performance time. Outcomes were measured with self-assessment instruments.

Reduction in postoperative sore throat by preoperative nebulization with dexmedetomidine, ketamine or saline: A prospective, randomized-controlled trial

Background and Aims

Postoperative sore throat (POST) is a minor but distressing complication following general anesthesia. The current literature on the effect of preoperative nebulization with dexmedetomidine, or ketamine on POST is, however, sparse. So, we compared the effect of preoperative nebulization with these drugs on POST.

Material and Methods

One hundred and thirty-two American Society of Anaesthesiology (ASA) grade I-II patients undergoing elective laparoscopic surgeries under general anesthesia were randomized into three equal groups: D, K, or C to receive dexmedetomidine, ketamine, or saline as preoperative nebulization, respectively. The primary objective was to compare the incidence and severity of POST, as inferred from the patient interviews at 2, 6, 12, 24-h postoperatively.

Results

Group D had a significantly lower incidence (29.5%) and severity (12: mild; 1: moderate) of POST compared to group K (54.5% [21: mild; 3: moderate]) and group C (56.8% [19: mild; 6: moderate]), at 2-h postoperatively. The same trend was observed at 6-h postoperatively (group D: 22.7% [9: mild; 1: moderate]); group K: (40.9% [17: mild; 1: moderate]); group C (50% [17: mild; 5: moderate]). The mean arterial pressure was significantly lower in group D at 15 min intraoperatively (84.09 mmHg, P = 0.018) and immediate postoperatively (97.60 mmHg, P = 0.034). The postoperative sedation, nausea, and vomiting was not statistically significant.

Conclusion

Preoperative nebulization with dexmedetomidine is effective in the reduction of the incidence and severity of early POST.

National Sjögren's Foundation Survey: Burden of Oral and Systemic Involvement on Quality of Life

OBJECTIVE

To define the association between oral and systemic manifestations of Sjögren syndrome (SS) and quality of life (QOL).

METHODS

We analyzed a cross-sectional survey conducted by the Sjögren's Foundation in 2016, with 2961 eligible responses. We defined oral symptom and sign exposures as parotid gland swelling, dry mouth, mouth ulcers/sores, oral candidiasis, trouble speaking, choking or dysphagia, sialolithiasis or gland infection, and dental caries. Systemic exposures included interstitial lung disease, purpura/petechiae/cryoglobulinemia, vasculitis, neuropathy, leukopenia, interstitial nephritis, renal tubular acidosis, autoimmune hepatitis, primary biliary cholangitis, or lymphoma. Outcomes included SS-specific QOL questions generated by SS experts and patients.

RESULTS

Using multivariable regression models adjusted for age, sex, race, and employment, we observed that mouth ulcers or sores, trouble speaking, and dysphagia were associated with poor quality of life. The following oral aspects had the greatest effect on the following QOL areas: (1) mouth ulcers/sores on the challenge and burden of living with SS (OR 4.26, 95% CI 2.89-6.28); (2) trouble speaking on memory and concentration (OR 4.24, 95% CI 3.28-5.48); and (3) dysphagia on functional interference (OR 4.25, 95% CI 3.13-5.79). In contrast, systemic manifestations were associated with QOL to a lesser extent or not at all.

CONCLUSION

Oral manifestations of SS, particularly mouth ulcers or sores, trouble speaking, and dysphagia, were strongly associated with worse QOL. Further study and targeted treatment of these oral manifestations provides the opportunity to improve quality of life in patients with SS.

Immediate effect of surface laryngeal hydration associated with tongue trill technique in amateur singers

PURPOSE

To analyze the immediate effect of laryngeal surface hydration associated with the performance of Tongue Trills (TT) on singers.

METHODS

Thirty singers without vocal complaints or laryngeal alterations divided into control (CG) and experimental (EG) groups. The CG performed the TT for five minutes. The EG was submitted a nebulization with 3 ml of saline solution followed by TT for five minutes. Voice self-assessment, acoustic analysis and perceptual assessment were performed at Pre (Pre TT) and post (PTT) moments in CG and pre (Pre TT), post hydration (PH) and post hydration + TT (PHTT) in GE. In the self-assessment were evaluated quality, stability, vocal intensity and hoarseness. There were extract the values of the Fundamental frequency; Jitter%; Shimmer%, Noise-to-harmonic Ratio e Cepstral Peak Prominence-Smoothed (CPPs) in the acoustic analyze. The perceptual evaluation was performed by an experienced speech therapist.

RESULTS

Comparing the results of self-assessment between groups showed improvement in the perception of stability and vocal intensity in the PTT (CG) in relation to PH (EG). Comparison between the EG moments showed a statistical difference in the vocal intensity perception, indicating a better results for PHTT. There was no statistical difference between the groups investigated in the perceptual assessments and acoustic analysis.

CONCLUSION

Surface laryngeal hydration does not potentiate the effect of TT on naturally hydrated singers with 3ml nebulization. For voice professionals with high vocal demand, surface hydration can be introduced during voice use to maintain vocal quality.

Quantifying the auto-oscillation complexity following water spraying with interest for phonation

Human voiced sound production or phonation is the result of a fluid-structure instability in the larynx leading to vocal folds auto-oscillation. In this paper, the effect of surface hydration following water spraying (0 up to 5 ml) on an ongoing auto-oscillation is studied experimentally using different mechanical deformable vocal folds replicas. The complexity of the oscillation is quantified on the upstream pressure by a phase space recurrence and complexity analysis. It is shown that: (1) the ratio of the degree of determinism to the recurrence rate of the phase space states γ and (2) estimated correlation dimension D_{2} are suitable parameters to grasp the effect of hydration on the oscillation pattern. The oscillation regime after hydration can either remain deterministic or approach a chaotic regime depending on initial conditions prior to water spraying, such as elasticity, glottal aperture, as well as oscillation complexity.

Nebulizer Use in Adults With Subglottic Stenosis: A Survey Study

Objective:

People with subglottic stenosis (SGS) may experience laryngeal symptoms that pose significant challenges to management. This study surveyed the use and effects of nebulized treatments on laryngeal symptoms in a large cohort of adults with SGS.

Methods:

A survey of nebulized treatment practices was distributed to an online international community of over 2000 members; 316 individuals (298 female, 1 male, 17 declined to specify; age 25+ years) completed the survey.

Results:

Nearly half (144) of participants had tried a nebulizer in the past. Among those, half currently used nebulized treatments; the majority used these treatments regularly and for greater than 1 year. The most frequently reported treatments included isotonic saline (0.9% Na+Cl–) or hypertonic saline (3% Na+Cl–). Symptoms improved by these treatments included thick mucus (69%), cough (57%), throat dryness (31%), stridor (28%), and voice (15%). The most frequently reported limitations to nebulizer use included time, noise, and portability.

Conclusion:

Among those individuals with SGS who have tried nebulized treatments, nearly half experienced relief from secondary laryngeal symptoms. Additional efficacy research is needed, particularly with respect to treatment type and dosage. The results are encouraging given the adverse impact these laryngeal symptoms can have on activities of daily living and quality of life.

Voice Disorders in Obstructive Sleep Apnea: Prevalence, Risk Factors, and the Role of CPAP

OBJECTIVE

Obstructive sleep apnea (OSA) is characterized by frequent interruptions in breathing related to upper airway collapse during sleep and may adversely affect phonatory function. This study aimed to: (1) establish the prevalence, risks, and quality of life burden of voice disorders in OSA and (2) explore the relation between voice disorders and positive airway pressure (PAP) therapy.

STUDY DESIGN

Cross-sectional, descriptive epidemiology study.

METHODS

Analyses were based on 94 individuals with OSA (53 men, 41 women; mean age = 54.7 ± 12.8 years) who completed a telephone interview.

RESULTS

Twenty-eight percent of participants reported having a current voice disorder. Of those with a current voice disorder, 83% had experienced symptoms for at least a year, and 58% had symptoms for at least 4 years. The prevalence of a current voice disorder was greater in women than men (44% vs 15%, P = .0020) but did not vary significantly across different age groups, body mass index (BMI), apnea/hypopnea index (AHI) severity, or medical history. After adjusting for sex, consistent use of PAP therapy (with humidification) was associated with (1) lower occurrence of voice disorders in women (Mantel-Haenszel [MH] χ²P = .0195), (2) reduced snoring severity accompanied by fewer voice disorders in men (MH χ²P = .0101), and (3) fewer reports of acid reflux as a possible trigger for voice problems (MH χ²P = .0226). Patients with OSA who also had a current voice disorder experienced lower overall quality of life compared to those without.

CONCLUSIONS

Chronic, longstanding voice disorders are common in women with OSA and produce significant adverse effects on quality of life. Nightly PAP use (with humidification) was associated with fewer voice symptoms and reduced severity of snoring and acid reflux as possible contributors. Further research is necessary to better understand the origin of these voice disorders in OSA and their potential response to treatment.

Self-perception of surface hydration effect on teachers’ voice quality: an intervention study

ABSTRACT Objective: to assess the effects of surface hydration on vocal quality according to teachers’ self-perception. Methods: an examiner-blinded pre-test and post-test intervention study carried out with a single group of 27 teachers. Sociodemographic characteristics and work questionnaire, Screening Index for Voice Disorder, Vocal Severity Rating Scale, Expected Effects Pre-intervention, Perceived Effects Post-intervention and Post-intervention Perception instruments, were applied. The intervention lasted 4 weeks and consisted of 5 minutes of nebulization with saline solution (sodium chloride 0.9%), after 10 minutes of mouth dehydration, prior to teaching. Results: screening Index for Voice Disorder scores demonstrated a statistically significant reduction (p=0.001). Frequency of voice disorders in the Vocal Severity Rating Scale was reduced without a statistical significance (p= 0.172). Expected Effects, Pre-intervention, and Perceived Effects, Post-intervention, showed improvement in vocal quality (40.7%), vocal comfort (40.7%) and vocal folds hydration (37%). Post-intervention perception form showed moderate improvement of the symptoms (59.3%), cleared voice (55.6%) and ease speaking (48.1%) as well as intense belief in the intervention (74.1%) and intense compliance to the intervention (74.1%). Conclusion: surface hydration with saline solution promoted self-perceived improvement in vocal quality.

A Method to Administer Agents to the Larynx in an Awake Large Animal

PURPOSE

This research note describes an adapted experimental methodology to administer an exogenous agent to the larynx and upper airway of awake animals. The exogenous agent could be a perturbation. In the current study, the agent was isotonic saline. Isotonic saline was selected because it is safe, of similar composition to extracellular fluid, and used in voice studies. The described approach allowed large animals such as pigs to be comfortably restrained without chemical sedation or anesthesia for extended periods while receiving the agent.

METHOD

Six Sinclair pigs were successfully trained with positive reinforcement to voluntarily enter and then be restrained in a Panepinto Sling. Once restrained, the pigs accepted a nose cone that delivered nebulized isotonic saline. This procedure was repeated 3 times per day for 20 days. At the end of the study, the larynx and airway tissues were excised and examined using histology and transmission electron microscopy.

RESULTS

Pathology related to the procedure (i.e., nebulized inhaled isotonic saline or stress) was not identified in any examined tissues.

CONCLUSIONS

This methodology allowed for repeated application of exogenous agents to awake, unstressed animals. This method can be used repeatedly in the laboratory to test various therapeutics for safety, toxicity, and dosage. Future studies will specifically manipulate the type of agent to further our understanding of laryngeal pathobiology.

Vocal Loading and Environmental Humidity Effects in Older Adults

The goal of this study was to investigate the effects of a vocal loading challenge that combined prolonged speaking, in child-directed voice within a noisy environment, in older adults. An additional goal was to determine whether increased environmental humidity would attenuate the negative effects of this vocal loading challenge.

METHOD

Thirteen healthy subjects (five males and eight females; >65 years) completed a vocal loading challenge. The challenge involved 45 minutes of child-directed speech in the presence of 65 dB multitalker babble background noise. Subjects completed this challenge in both low humidity and moderate humidity in counterbalanced order. Vocal function was assessed before and after the challenge using phonation threshold pressure (PTP), cepstral peak prominence (CPP), low/high spectral ratio (LHR), perceived phonatory effort (PPE), and perceived vocal tiredness.

RESULTS

Negative changes were observed in the aging larynx following the 45-minute vocal loading challenge. Measures of PTP, PPE, and perceived vocal tiredness demonstrated statistically significant loading effects. Increased ambient humidity significantly alleviated the negative changes observed in PPE and perceived vocal tiredness. Increased humidity significantly improved CPP measures both before and after the vocal loading challenge.

CONCLUSIONS

This study furthers our understanding of how older adults respond to a vocal loading challenge of prolonged nonhabitual speech in a noisy environment. Our data suggest that the aging voice is negatively affected by prolonged loud speaking and that humidification may be beneficial in reducing some of these negative effects.

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

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.

Management of interstitial lung disease associated with connective tissue disease

The lung is a common site of complications of systemic connective tissue disease (CTD), and lung involvement can present in several ways. Interstitial lung disease (ILD) and pulmonary hypertension are the most common lung manifestations in CTD. Although it is generally thought that interstitial lung disease develops later on in CTD it is often the initial presentation ("lung dominant" CTD). ILD can be present in most types of CTD, including rheumatoid arthritis, scleroderma, systemic lupus erythematosus, polymyositis or dermatomyositis, Sjögren's syndrome, and mixed connective tissue disease. Despite similarities in clinical and pathologic presentation, the prognosis and treatment of CTD associated ILD (CTD-ILD) can differ greatly from that of other forms of ILD, such as idiopathic pulmonary fibrosis. Pulmonary hypertension (PH) can present as a primary vasculopathy in pulmonary arterial hypertension or in association with ILD (PH-ILD). Therefore, detailed history, physical examination, targeted serologic testing, and, occasionally, lung biopsy are needed to diagnose CTD-ILD, whereas both non-invasive and invasive assessments of pulmonary hemodynamics are needed to diagnose pulmonary hypertension. Immunosuppression is the mainstay of treatment for ILD, although data from randomized controlled trials (RCTs) to support specific treatments are lacking. Furthermore, treatment strategies vary according to the clinical situation-for example, the treatment of a patient newly diagnosed as having CTD-ILD differs from that of someone with an acute exacerbation of the disease. Immunosuppression is indicated only in select cases of pulmonary arterial hypertension related to CTD; more commonly, selective pulmonary vasodilators are used. For both diseases, comorbidities such as sleep disordered breathing, symptoms of dyspnea, and cough should be evaluated and treated. Lung transplantation should be considered in patients with advanced disease but is not always feasible because of other manifestations of CTD and comorbidities. Clinical trials of novel therapies including immunosuppressive therapies are needed to inform best treatment strategies.

Subjective and objective voice evaluation in Sjögren's syndrome

Objective The aim of this study is to assess the subjective and objective aspects of voice in Sjögren's syndrome. Methods The study enrolled 10 women with Sjögren's syndrome and 12 healthy women. Maximum phonation time, fundamental frequency, jitter, shimmer, and noise-to-harmonics ratio were determined during acoustic voice analysis. The Stroboscopy Evaluation Rating Form was used for the laryngostroboscopic evaluation. A subjective evaluation was performed using the Turkish version of Voice Handicap Index-10. Results The mean age of the Sjögren's syndrome and control groups was 46 ± 13.89 and 41.27 ± 6.99 years, respectively, and did not differ (P = 0.131). In the laryngostroboscopic evaluation, the smoothness and straightness of vocal folds, regularity, and glottal closure differed significantly. In the acoustic and aerodynamic analyses, none of the parameters differed statistically, while the Sjögren's syndrome group had significantly higher Voice Handicap Index-10 scores than the controls. Conclusion Sjögren's syndrome affects the voice and voice quality.

The Quality of Life Burden Associated With Voice Disorders in Sjögren's Syndrome

OBJECTIVES

This study examined quality of life burden of voice disorders in Sjögren's syndrome (SS).

METHODS

Patients with SS (n = 101) completed interviews involving patient-reported histories of voice disorders, specific voice symptoms, SS disease severity, the Voice-Related Quality of Life (V-RQOL), and the general health-related quality of life Short Form 36 (SF-36) questionnaires. Relationships among voice symptoms, disease severity, and quality-of-life measures were examined and compared with patient-reported voice disorders.

RESULTS

Significant correlations were observed among voice symptoms, disease severity, V-RQOL, SF-36, and patient-reported voice disorders (P < .05). Patients with SS who reported a voice disorder experienced a greater burden on general quality of life as compared with those without voice disorders. Specific voice symptoms significantly correlated with reduced SF-36 scores included frequent throat-clearing, throat soreness, difficulty projecting, and vocal discomfort. Despite the added burden of a voice disorder on quality of life in SS, voice-related treatment seeking was low (15.8%). However, the majority of patients who received voice treatment reported voice improvement.

CONCLUSIONS

Individuals with SS frequently experience voice disorders and specific voice-related symptoms that are associated with reduced quality of life. These findings have important implications for voice referral practices and voice disorder symptom management in this population.

Nebulized isotonic saline improves voice production in Sjögren's syndrome

OBJECTIVE

This study examined the effects of a topical vocal fold hydration treatment on voice production over time.

STUDY DESIGN

Prospective, longitudinal, within-subjects A (baseline), B (treatment), A (withdrawal/reversal), B (treatment) experimental design.

METHODS

Eight individuals with primary Sjögren's syndrome (SS), an autoimmune disease causing laryngeal dryness, completed an 8-week A-B-A-B experiment. Participants performed twice-daily audio recordings of connected speech and sustained vowels and then rated vocal effort, mouth dryness, and throat dryness. Two-week treatment phases introduced twice-daily 9-mL doses of nebulized isotonic saline (0.9% Na(+)Cl(-)). Voice handicap and patient-based measures of SS disease severity were collected before and after each 2-week phase. Connected speech and sustained vowels were analyzed using the Cepstral Spectral Index of Dysphonia (CSID). Acoustic and patient-based ratings during each baseline and treatment phase were analyzed and compared.

RESULTS

Baseline CSID and patient-based ratings were in the mild-to-moderate range. CSID measures of voice severity improved by approximately 20% with nebulized saline treatment and worsened during treatment withdrawal. Posttreatment CSID values fell within the normal-to-mild range. Similar patterns were observed in patient-based ratings of vocal effort and dryness. CSID values and patient-based ratings correlated significantly (P < .05).

CONCLUSION

Nebulized isotonic saline improves voice production based on acoustic and patient-based ratings of voice severity. Future work should optimize topical vocal fold hydration treatment formulations, dose, and delivery methodologies for various patient populations. This study lays the groundwork for future topical vocal fold hydration treatment development to manage and possibly prevent dehydration-related voice disorders.

LEVEL OF EVIDENCE

2b.

Reducing the negative vocal effects of superficial laryngeal dehydration with humidification

OBJECTIVES

Environmental humidification is a simple, cost-effective method believed to reduce superficial laryngeal drying. This study sought to validate this belief by investigating whether humidification treatment would reduce the negative effects of superficial laryngeal dehydration on phonation threshold pressure (PTP). Phonation threshold pressure data analysis may be vulnerable to bias because of lack of investigator blinding. Consequently, this study investigated the extent of PTP analysis reliability between unblinded and blinded investigators.

METHODS

Healthy male and female adults were assigned to a vocal fatigue (n = 20) or control group (n = 20) based on their responses to a questionnaire. PTP was assessed after 2 hours of mouth breathing in low humidity (dehydration challenge), following a 5-minute break in ambient humidity, and after 2 hours of mouth breathing in high humidity (humidification).

RESULTS

PTP significantly increased following the laryngeal dehydration challenge. After humidification, PTP returned toward baseline. These effects were observed in both subject groups. PTP measurements were highly correlated between the unblinded and blinded investigator.

CONCLUSIONS

Humidification may be an effective approach to decrease the detrimental voice effects of superficial laryngeal dehydration. These data lay the foundation for future investigations aimed at preventing and treating the negative voice changes associated with chronic, surface laryngeal drying.