Work-Related Communicative Profile of Voice Teachers: Effects of Classroom Noise on Voice and Hearing Abilities

PurposeVocal instructors during their normal workday are exposed to high noise levels that can affect their voice and hearing health. The goal of this study was to evaluate the voice and hearing status of voice instructors before and after lessons and relate these evaluations with voice and noise dosimetry taken during lessons.MethodsEight voice instructors volunteered to participate in the study. The protocol included (1) questionnaires, (2) pre/post assessment of voice quality and hearing status, and (3) voice and noise dosimetry during lessons. Acoustic measurements were taken of the unoccupied classrooms.ResultsIn six of eight classrooms, the measured noise level was higher than the safety recommendations set by National Institute for Occupational Safety and Health. The background noise level and the reverberation time in the classrooms were in compliance with the national standard recommendations. We did not find a clear pattern comparing pre- and post-measurements of voice quality consistent among genders. In all subjects, the Sound Pressure Levels mean increased, and the standard deviation of fundamental frequency decreased indicating association to vocal fatigue. Previous studies link these changes to increasing vocal fatigue. The audiometric results revealed seven out of eight instructors have sensorineural hearing loss.ConclusionsThe interaction of the acoustic space and noise levels can contribute to the development of hearing and voice disorders for voice instructors. If supported by larger sample size, the results of this pilot study could justify the need for a hearing and voice conservation program for music faculty.     

The effect of voice amplification on occupational vocal dose in elementary school teachers

Two elementary school teachers, one with and one without a history of vocal complaints, wore a vocal dosimeter all day at school for a 3-week period. In the second week, each teacher wore a portable voice amplifier. Each teacher showed a reduction in vocal intensity during the week of amplification, with a larger effect for the teacher with vocal difficulties. This teacher also showed a decrease in hourly vocal fold distance dose as measured by the dosimeter despite incurring longer phonation times. Fundamental frequency and vocal fold cycle dose did not appear to be affected by the use of amplification during the teaching day. Both teachers showed evidence of a possible moderate effect of adjusting vocal intensity in the week after amplification, possibly as a means to recalibrate their perceived vocal loudness. This study demonstrates the usefulness of both vocal dosimetry and amplification in monitoring and modifying vocal dose in an occupational setting and reinforces previous data suggesting the effectiveness of amplification in reducing the vocal load in schoolteachers. Implications of the data for future research regarding prevention and treatment of occupational voice disorders are discussed.     

The Influence of Auditory Feedback and Vocal Rehabilitation on Prelingual Hearing-Impaired Individuals Post Cochlear Implant

ObjectiveTo verify changes in the perceptual and acoustic vocal parameters in prelingual hearing-impaired adults with cochlear implants after vocal rehabilitation.HypothesisAuditory feedback restoration alone after cochlear implant is not enough for vocal adjustments. A targeted and specific voice therapy intervention is required.Study DesignProspective and pre–post repeated measures design.MethodsTwenty literate adults with severe to profound prelingual bilateral sensorineural hearing loss participated in the study; individuals were implanted late and were fluent users of oral language. Ages ranged from 17 to 48 years. All individuals presented normal results in laryngoscopy, and hearing thresholds with the cochlear implant were over 40 dB HL. Individuals were randomly distributed into two groups: Group 1 (treatment group) and Group 2 (control group), both with ten patients each, five men and five women, matching mean age and hearing deprivation time before the cochlear implantation. Patients from Group 1 underwent a protocol of vocal therapy including 12 individual sessions with the same clinician. Group 2 only underwent vocal recordings. The vocal recordings occurred before and after the participation in the therapy protocol for Group 1 and after the same period, 3 months later, without any intervention, for Group 2. The recording sessions used the Consensus Auditory-Perceptual Evaluation of Voice protocol sentence reading and emission of sustained vowel /a/. Auditory-perceptual evaluation of voices was performed by three judges, and the acoustical analysis used the Praat program.ResultsStatistically significant reductions in the overall vocal degree, vocal instability, and degree of resonance change were observed after vocal rehabilitation in Group 1. Statistically, individuals from Group 1 did not differ in regard to the modification of acoustic parameters. Group 2 did not present significant changes in any of the analyzed parameters.ConclusionsThe cochlear implanted adults submitted to vocal rehabilitation presented changes in the auditory-perceptual parameters, with reduction of the overall voice severity, vocal instability, and degree of resonance after vocal intervention. There were no changes in the acoustic parameters in the implanted prelingual hearing-impaired adult subjects.     

Vocal Fatigue—Do Young Speech-Language Pathologists Practice What They Preach?

PurposeSpeech-Language Pathologists can be categorized as Level II professional voice users who play the roles of voice therapist or vocal coach to treat voice problems. SLPs may be at the risk of experiencing vocal fatigue due to vocal loading and other contributing factors. The present study was undertaken to find the percentage of SLPs reporting vocal fatigue, the probable factors resulting in vocal fatigue, the measures that are taken to avoid/reduce the occurrence of vocal fatigue, its effect on their professional and personal life and the measures taken to tackle it.ResultsThe results of this study are based on data collected from 142 SLPs and 50 controls using a questionnaire. 71.13% SLPs reported that they experience vocal fatigue. Some of the contributing factors that are mainly reported are long durations of voice use, voice use for recreational purposes, speaking loudly, frequent throat clearing, lack of adequate hydration and working in noisy or air-conditioned environments. The major symptoms reported were dryness in throat, tightness in neck and shoulder, choking sensation, effortful speech and pain in the throat. 59% SLPs reported that vocal fatigue affected their professional life while 44% SLPs reported that it affects their personal life also to varying degrees. Measures taken to avoid/ reduce the occurrence of vocal fatigue included vocal warm up, break in between sessions, and play activities. Only a few SLPs took intervention measures like ENT consultation, voice therapy, and home remedies.ConclusionSLPs are inevitably at high risk of experiencing vocal fatigue which, if left untreated, will lead to organic voice problems. However, many young SLPs who experience vocal fatigue reported vocal abuse, do not follow vocal hygiene program and do not follow evidence-based preventive or intervention practices to treat vocal fatigue.     

The aging adult voice

Advancing age produces physiologic changes that may alter voice. Some of these changes are inevitable; others may be avoidable or reversible. In addition, many treatable medical conditions may cause voice changes similar to those of aging. It is essential that all voice care providers be familiar with the expected changes of aging, and be alert to reversible conditions that may adversely affect phonation and be mistaken for presbyphonia.     

Pitch (F0) and formant profiles of human vowels and vowel-like baboon grunts: the role of vocalizer body size and voice-acoustic allometry

Key voice features--fundamental frequency (F0) and formant frequencies--can vary extensively between individuals. Much of the variation can be traced to differences in the size of the larynx and vocal-tract cavities, but whether these differences in turn simply reflect differences in speaker body size (i.e., neutral vocal allometry) remains unclear. Quantitative analyses were therefore undertaken to test the relationship between speaker body size and voice F0 and formant frequencies for human vowels. To test the taxonomic generality of the relationships, the same analyses were conducted on the vowel-like grunts of baboons, whose phylogenetic proximity to humans and similar vocal production biology and voice acoustic patterns recommend them for such comparative research. For adults of both species, males were larger than females and had lower mean voice F0 and formant frequencies. However, beyond this, F0 variation did not track body-size variation between the sexes in either species, nor within sexes in humans. In humans, formant variation correlated significantly with speaker height but only in males and not in females. Implications for general vocal allometry are discussed as are implications for speech origins theories, and challenges to them, related to laryngeal position and vocal tract length.     

Vocal aging and the impact on daily life: a longitudinal study

Longitudinal studies on vocal aging are scarce, and information on the impact of age-related voice changes on daily life is lacking. This longitudinal study reports on age-related voice changes and the impact on daily life over a time period of 5 years on 11 healthy male speakers, age ranging from 50 to 81 years. All males completed a questionnaire on vocal performance in daily life, and perceptual and acoustical analyses of vocal quality and analyses of maximum performance tasks of vocal function (voice range profile) were performed. Results showed a significant deterioration of the acoustic voice signal as well as increased ratings on vocal roughness judged by experts after the time period of 5 years. An increase of self-reported voice instability and the tendency to avoid social parties supported these findings. Smoking males had a lower speaking fundamental frequency compared with nonsmoking males, and this seemed reversible for males who stop smoking. This study suggests a normal gradual vocal aging process with clear consequences in daily life, which should be taken into consideration in clinical practice as well as in studies concerning communication in social life.     

A Preliminary Study of Vocal Health Among Collegiate A Cappella Singers

ObjectiveCollegiate a cappella groups have grown significantly in popularity and prominence; however, there have been few studies that evaluate the vocal health of this subgroup of young singers. The objective of this preliminary study was to conduct a multiparametric evaluation of the vocal health characteristics of a sample of collegiate a cappella singers. We further tested whether differences in vocal health assessments exist between a cappella singers with and without vocal training and trained collegiate singers who do not participate in a cappella groups.Study designPoint prevalence study.MethodsForty-one collegiate singers participated in this study. Participants were divided into the following three groups: trained singers (TS), trained a cappella singers (ATS), and untrained a cappella singers (AUS). Participants were administered a set of surveys to assess self-perception of singing voice health and perceived access and attitudes toward voice-related health care. Acoustic and laryngoscopic assessments of participant's speaking and singing voice was performed and validated vocal health questionnaires administered as a means to objectively evaluate for the presence of voice problems.ResultsOverall, 87.5% of the ATS and 60% of the AUS groups reported experiencing problems with their singing voice. However, no vocal abnormalities were detected during laryngoscopic and acoustic assessments. Furthermore, minimal differences between any of the measured vocal health parameters were observed between the TS, ATS, and AUS groups.ConclusionCollectively, a high percentage of collegiate a cappella singers with and without vocal training report singing voice problems. However, our sample of a cappella singers did not have increased singing voice problems as compared to vocally trained collegiate singers not in a cappella groups. We did find that a cappella singers may be more inclined to seek information about maintaining a healthy singing voice from their fellow musicians as opposed to singing teachers or other voice health professionals. Singing teachers, otolaryngologists, and speech-language pathologists may need to play a more active role in educating a cappella singers regarding maintaining good vocal health.     

Studying vocal fold vibrations in Parkinson's disease with a nonlinear model

A nonlinear model is applied to study pathologic vocal vibratory characteristics and voice treatments of Parkinson's disease. We find that a number of pathologic vocal characteristics commonly observed in Parkinson's disease, including reduced vibratory intensity, incomplete vocal closure, increased phonation threshold pressure, glottal tremor, subharmonics, and chaotic vocal fold vibrations, can be studied with this nonlinear model. We also find that two kinds of clinical voice treatments for Parkinson's disease, including respiratory effort treatment and Lee Silverman voice treatment can be studied with this computer model. Results suggest that respiratory effort treatment, in which subglottal pressure is increased, might aid in enhancing vibratory intensity, improving glottal closure, and avoiding vibratory irregularity. However, the Lee Silverman voice treatment, in which both subglottal pressure and vocal fold adduction are increased, might be better than respiratory effort treatment. Increasing vocal fold thickness would be further helpful to improve these pathologic characteristics. The model studies show consistencies with clinical observations. Computer models may be of value in understanding the dynamic mechanism of disordered voices and studying voice treatment effects in Parkinson's disease.     

Investigating the Effects of Caffeine on Phonation

Objective

A core component of vocal hygiene programs is the avoidance of agents that may dry the vocal folds. Clinicians commonly recommend that individuals reduce caffeine intake because of its presumed dehydrating effects on the voice. However, there is little evidence that ingestion of caffeine is detrimental to voice production. The first objective of this study was to evaluate whether caffeine adversely affects voice production. The second objective was to evaluate if caffeine exacerbates the adverse phonatory effects of vocal loading.

Study Design

Prospective, double-blinded, sham-controlled study.

Methods

Sixteen healthy adults participated in two sessions where they consumed caffeine (caffeine concentration = 480 mg) or sham (caffeine concentration = 24 mg) beverages. Voice measures (phonation threshold pressure and perceived phonatory effort) were collected. Subjects then completed a vocal loading challenge and voice measures were obtained again.

Results

There were no significant differences in voice measures between the caffeine and sham conditions. Ingestion of caffeine did not adversely affect voice production (P > 0.05) or exacerbate the detrimental phonatory effects of vocal loading (P > 0.05).

Conclusions

Our findings contribute to emerging knowledge on the effects of caffeine on voice production. Recommendations to completely eliminate caffeine from the diet, as a component of a vocal hygiene program, should be evaluated on an individual basis.     

Voice and Lifestyle Behaviors of Speech-Language Pathology Students: Impact of History Gathering Method on Self-Reported Data

ObjectivesThis study described voice use and lifestyle information from student speech-language pathologists (SLP) and assessed the impact of history gathering method on the acquired data.MethodsOne hundred sixty-two SLP students completed a detailed history form and estimated voice and life style parameters at study intake and subsequently tracked the same parameters daily for three consecutive weeks. Nonparametric statistical comparisons were applied to assess differences in estimates at intake versus the 3-week log.ResultsVoice problems diagnosed by a physician or SLP were reported by 11% of the students. A similar percentage reported frequent loud talking and heavy occupational voice demands beyond clinical training use. Furthermore, high stress was reported by 49%, frequent anxiety by 53%, and depression by 17%. Comparing data from study intake relative to the 3-week log, SLP students statistically significantly overestimated speaking time, and underestimated singing, second hand smoke exposure time, and hours of sleep. Additionally, they overestimated water intake and daily stress, and underestimated caffeine and alcohol intake, at the study onset versus the log. The experience of vocal fatigue was common within the 3-week log, but how a student identified at study intake on this parameter (experiencing it frequently or not) did not differentiate how many days of vocal fatigue were reported in 3 weeks.ConclusionsSLP students engage in some voice use and lifestyle behaviors that place them at risk for voice problems. The method of soliciting information about the voice and lifestyle of SLP students impacted the information obtained. Optimal methods of gathering accurate and reliable clinical history and voice us data are needed.     

Average speaking fundamental frequency in soprano singers with and without symptoms of vocal attrition

Nineteen trained soprano singers aged 18–30 years vocalized tasks designed to assess average speaking fundamental frequency (SFF) during spontaneous speaking and reading. Vocal range and perceptual characteristics while singing with low intensity and high frequency were also assessed, and subjects completed a survey of vocal habits/symptoms. Recorded signals were digitized prior to being analyzed for SFF using the Kay Computerized Speech Lab program. Subjects were assigned to a normal voice or impaired voice group based on ratings of perceptual tasks and survey results. Data analysis showed group differences in mean SFF, no differences in vocal range, higher mean SFF values for reading than speaking, and 58% ability to perceive speaking in low pitch. The role of speaking in too low pitch as causal for vocal symptoms and need for voice classification differentiation in vocal performance studies are discussed.     

The singing/acting voice in the mature adult

With years of training and performance, the mature vocal performer experiences less vocal changes with aging than does his/her age peer who is not a performer. We have considered, some physical problems that may adversely influence the voice of the older performer. With some awareness and effective management of these possible problems, the negative effects on the older performer's voice can be minimized.     

Evaluation of Voice Quality in Patients With Vocal Fold Polyps: The Size of a Polyp Matters or Does it?

ObjectiveThis study aimed to investigate the correlation between morphological features of vocal fold polyps (VFPs) and subjective/objective voice parameters.MethodsPerceptual evaluations, aerodynamic and acoustic tests were performed on 47 patients with VFPs. Still images were captured from video and the morphological features associated with the size of VFP were quantified. To reveal the correlation between size-related morphological features (length of polyp base, the ratio of polyp base to vocal fold length, glottal gap area) and objective/subjective parameters of voice, Pearson's and Spearman's tests were carried out.ResultsThis cohort was composed of 30 (63.8 %) male and 17 (36.2%) female patients with the mean age of 45.2 years and 41.3 years, respectively. No correlation was found between the morphological features of VFPs and any of perceptual, aerodynamic and acoustic voice parameters.ConclusionsOur findings indicated that controversies still exist regarding the role of vocal fold polyp morphology in clinical decision making.     

Laryngeal function and vocal fatigue after prolonged reading in individuals with unilateral vocal fold paralysis

The purpose of the present study was to examine the effect of prolonged loud reading, intended to induce fatigue, on vocal function in adults with unilateral vocal fold paralysis (UVFP). Subjects were 20 adults, 37–60 years old, with UVFP secondary to recurrent laryngeal nerve paralysis. Subjective ratings and instrumental measures of vocal function were obtained before and after reading. Statistical analysis revealed subjects rated their vocal quality and physical effort for voicing more severely following prolonged loud reading, whereas expert raters did not detect a significant perceptual difference in vocal quality. Reading fundamental frequency (Fo) was significantly increased following prolonged loud reading, as were mean airflow rates at all pitch conditions. Maximum phonation times for comfort and low pitches significantly decreased during posttests. Multiple regression analyses revealed significant associations between ratings of posttest physical effort and select posttest measures. Interpretation of results indicates the prolonged loud reading task was successful in vocally fatiguing most of the UVFP subjects. Key physiologic correlates of vocal fatigue, in individuals with UVFP, include further reduction of glottic efficiency, resulting in decreased regulation of glottic airflow and a temporary destabilization of speaking fundamental frequency.     

Protocol Challenges for On-the-Job Voice Dosimetry of Teachers in the United States and Finland

The occupational voice use of teachers has been an important research topic over the last 10 years. However, data collection on vocal loading in teachers at and away from the workplace poses significant challenges to the research protocol. The challenges include recruitment of subjects, voice data collection on the job, and subject compliance and retention. The present article offers recommendations for coping with these protocol difficulties. The recommendations are based on the authors' experiences with long-term, on-the-job voice dosimetry of large subject groups of teachers in the United States and Finland.