Educative processes in the vocal health of teachers: a literature review of Brazilian studies in Speech-Language Pathology and Audiology
This literature review analyzes the educative processes of vocal healthc actions aimed at teachers discussed in Speech-Language Pathology and Audiology literature produced in Brazil. Our corpus consisted of 63 studies on collective intervention published between 1994 and 2008. The analysis emphasizes the distribution of publications over time; the characterization of the type of educative process (unilateral or dialogic, democratic, participatory and problema-based); the themes/content addressed; the form of development (precise or procedural); and the organization of actions (individually centered or expanded towards working issues). It was observed that 74% of the actions were developed in processes, such as courses, workshops or voice training. The average length of each meeting ranged from 20 minutes to four hours. Seventy nine percent of the educative strategies employed were characterized as unilateral and inconsistent with proposals based on healthcare promotion. The most common themes and topics were: vocal habits/behaviors and vocal hygiene/health (71%); warming up and cooling down, vocal exercises and techniques (50%); anatomy and physiology of vocal production and oral sensorimotor system (44%); vocal parameters (23%); work environment (22%), and use of voice, communication and expression (20%). The focus of the educative process is the individual (100%) and it is generally conducted without considering work conditions, health and quality of life. Work environment aspects were contemplated in only 17% of the publications, teachers’ work organization, in 6%, and school community, in 1%. It was identified the need for organization and revision of forms of development, dynamics, strategies, themes and contents, type and focus of the educative process of public healthcare actions aiming at teachers’ vocal health, according to the perspective of health promotion.
The Effect of Resonance Tubes on Glottal Contact Quotient With and Without Task Instruction: A Comparison of Trained and Untrained Voices
Phonation into narrow tubes or straws has been used as a voice training and voice therapy technique and belongs to a group of techniques known as semi-occluded vocal tract exercises. The use of what are called resonance tubes has received renewed attention in the voice research literature, in both theoretical and empirical studies. The assumption is that the partially occluded and lengthened vocal tract alters supraglottal acoustics in such a way as to allow phonation near a lowered first vocal tract formant, which has been suggested as a way to bring about a more efficient glottal closure pattern for sustained oscillation. In this study, two groups of male participants, 10 with no vocal training and 10 with classical vocal training, phonated into a resonance tube for approximately 1 minute. Electroglottography was used to estimate glottal contact quotient (CQ) during spoken /a/ vowels before tube phonation, during tube phonation, and again during spoken /a/ vowels after tube phonation. Half of each group of participants was made to keep pitch and loudness consistent for all phases of the experiment, replicating the method of a previous study by this author. The other half was instructed to practice phonating into the resonance tube before collecting data and was encouraged to find a pitch and loudness combination that maximized ease of phonation and a sense of forward oral resonance. Glottal CQ altered considerably from baseline for almost all participants during tube phonation, with a larger variability than that during vowel production. Small differences in glottal CQ were found as a function of training and instruction, with most participants’ CQ increasing during tube phonation. A small post-tube phonation effect was found primarily for the trained and instructed group. Secondary single-subject analyses revealed large intersubject variation, highlighting the highly individualized response to the resonance tube task. Continued study of resonance tubes is recommended, comparing both male and female as well as vocally trained and untrained participants. Future studies should continue to examine systematic variations in task instruction, length of practice, and resonance tube dimensions.
from the Journal of Voice
CONCLUSION: The term oral expressiveness is not generally used by the subjects interviewed, due to the fact that its concept is new to them. The term comprises the conveyance of emotions and intention by the speaker. The following aspects were considered to interfere on oral expressiveness: listeners’ judgment; adequacy of the speech to the context; style of the radio station; and textual content of the message, evidencing the dynamics between subjective and social. More theoretical studies in Linguistics may subsidize less conceptually diverse practices when considering speech-language interventions.
Some Vocal Consequences of Sleep Deprivation and the Possibility of “Fatigue Proofing” the Voice With Voicecraft® Voice Training
When a person is sleep deprived, someone who knows them and their usual voice may comment that they sound tired, often supporting their observation with comments, which may include, “you sound croaky” or “rough,” or “you don’t sound too bright,” (meaning the voice and not intellectual capacity) or “you sound down” or “flat.” To explore the concept that fatigue may produce such recognizable, consistent, and measurable voice changes, a study was designed in which 15 participants underwent 24 hours of sleep deprivation. They were recorded at specific intervals reading a standard passage and the results indicated that the voices deteriorated. The team of trained listener judges perceived the voices as sounding more tired, specifically rougher and less brilliant and the acoustic analysis revealed that the mean fundamental frequency fell, providing some validation for the comments “croaky,” “not so bright,” and “down,” respectively. To explore the possibility of prevention of such deterioration, the participants subsequently received a specific voice training, followed by a second, identical sleep deprivation study. The results of the second, posttraining sleep deprivation study indicated that the voices had become more resilient to the effects of sleep deprivation. The results are discussed in light of the fact that such deterioration as a consequence of sleep deprivation may compromise the quality of vocal performance, contributing to vocal disorder, proving costly should it result in absence from work. Furthermore, for those fatigued individuals for whom a robust voice is essential, there may be a way to “fatigue proof” the voice.
from the Journal of Voice
Spectrographic analysis of male actors’ voices showed a cluster, the “actor’s formant” (AF), which is related to the perception of good and projected voice quality. To date, similar phenomena have not been described in the voices of actresses. Therefore, the objective of the current investigation was to compare actresses’ and nonactresses’ voices through acoustic analysis to verify the existence of the “AF” cluster or the strategies used to produce the performing voice. Thirty actresses and 30 nonactresses volunteered as subjects in the present study. All subjects read a 40-second text at both habitual and loud levels. Praat (v.5.1) was then used to analyze equivalent sound pressure level (Leq), speaking fundamental frequency (SFF), and in the long-term average spectrum window, the difference between the amplitude level of the fundamental frequency and first formant (L1 − L0), the spectral tilt (alpha ratio), and the amplitude and frequency of the “AF” region. Significant differences between the groups, in both levels, were observed for SFF and L1 − L0, with actresses presenting lower values. There were no significant differences between groups for Leq or alpha ratio at either level. There was no evidence of an “AF” cluster in the actresses’ voices. Voice projection for this group of actresses seemed to be mainly a result of a laryngeal setting instead of vocal tract resonances.
from the Journal of Voice
CONCLUSION: The voiced tongue vibration technique was more effective after a period of three minutes. The results confirmed the effectiveness of this technique, which is widely used in Speech-Language Pathology practice, defining the optimal period of time to perform it.
Effects of Vocal Training on Singing and Speaking Voice Characteristics in Vocally Healthy Adults and Children Based on Choral and Nonchoral Data
Significant positive effect of voice training on vocal capabilities, mostly singing voice, was confirmed. The presented norms for trained singers, with key parameters differentiated by gender and age, are suggested for clinical practice of otolaryngologists and speech-language pathologists.
from the Journal of Voice
Considerations regarding vocal and laryngeal modifications caused by vocal fry in women without voice complaints
The aim of this study was to verify vocal and laryngeal modifications caused by vocal fry in five female subjects without vocal or laryngeal complaints. For this purpose, the sustained emission of the vowel /a/ was digitally recorded, as well as the recording of a videostroboscopic examination of the larynx. Subsequently, the subjects performed the vocal fry in three series of 15 repetitions, with a 30-second interval of passive rest between series, and carried out a second evaluation (recording of the sustained emission of the vowel /a/ and the videostroboscopic examination of the larynx). Both laryngeal and vocal data found prior to and after the vocal fry technique were submitted to acoustic, auditory-perceptive, and videostroboscopic analyses. The acoustic analysis was generated by the Multi Speech program. Analyses showed the following effects of the vocal fry: increase of the vibration of the vocal folds mucosa; alteration or maintenance of voice type and pitch; decrease or maintenance of measures related to jitter and shimmer, as well as the index that suggests glottic noise; decrease of the soft phonation index; maintenance or alteration of the vocal quality and resonance focus, with laryngopharyngeal prevalence; decrease of the fundamental frequency; and increase of frequency and width variations. The study allowed the conclusion that vocal fry had a positive effect on the vibration of the vocal folds mucosa as well as on voice noise, and a negative effect on voice resonance and stability.
Tongue trill performance duration interfered with the vocal response of dysphonic women, with positive response predominance at m5. At m7, there was an increase of vocal tension and a drop in vocal quality.
from the Journal of Voice
Review of the Impact of Voice Training on the Vocal Quality of Professional Voice Users: Implications for Vocal Health and Recommendations for Further Research
Findings indicate that there is no conclusive evidence that voice training improves the vocal effectiveness of professional voice users, as a result of a range of methodological limitations of the included studies. However, some studies did show that voice training significantly improved the knowledge, awareness, and quality of voice. Therefore, there is a need for robust research to empirically confirm this, with implications for vocal health, and occupational safety and health policies.
from the Journal of Voice
Impact stress (IS) has been regarded as the main loading factor in voice production. To quantify the cost of voice production, an output-cost ratio (OCR) was proposed, which concerns acoustic output (pressure P) in relation to IS: OCR = 20 log Psup/P0 – 20 log IS/IS0 [1,2]. IS is difficult to measure directly in humans. However, it has been found to correlate with closed quotient (CQ, closed time/period length) measured by electroglottogram (CQEGG) . The present study proposes a noninvasive estimate of OCR, the quasi-output-cost ratio (QOCR): (sound pressure level (SPL)/CQEGG) × (period length (T)/T0). T0 is set at 0.005 for females and 0.01 for males, corresponding to the respective period lengths of the mean F0 in female and male speech (i.e. 200 and 100 Hz). QOCR was tested for 62 healthy females (23 teachers, 18 university students with voice training and 21 without). The teachers had a higher QOCR than the students in loud speech, but QOCR did not correlate with symptoms of vocal fatigue after a vocal loading test. QOCR seems to be a promising tool to quantify vocal loading but naturally not vocal loadedness.
Abstract The objective of this study was to design a voice training program for Chinese speakers, and to evaluate its efficacy. It was a prospective, randomized, case–control study practiced in three middle schools in Beijing, China. Teachers in the treatment group received voice training for 4 weeks, whereas the control group subjects received no treatment. The voice training program, which was adapted for Chinese, contained vocal hygiene education and group voice training. The outcome was assessed by voice handicap index (VHI), maximum phonation time (MPT) and acoustic analysis parameters including, noise to harmonic ratio (NHR), jitter and shimmer. The results showed that at the onset of the study, no significant differences were found between the subjects in two groups for VHI, MPT and NHR. VHI of treatment group subjects who received voice training decreased significantly, whereas VHI of control group subjects showed no significant change. Treatment group MPT was significantly increased after training, whereas the control group one presented no significant change during the same period. NHR in treatment group decreased significantly after training, whereas the one in control group showed no significant change. There were no significant changes for jitter and shimmer in both groups before and after the study. So we conclude that the voice training program is suitable to treat voice diseases, particularly for middle school teachers. This result provided reliable evidence for carrying out further voice training in China.
Training specific vocal techniques can be effective in treating nonorganic dysphonias. Evaluation of vocal function in these studies has included auditory-perceptual assessment, aerodynamic measurement, acoustic analysis, self-report, and visual inspection of the larynx. Reliability of judgments made using visual rating tools for nasendoscopic and videostroboscopic visualization of the larynx when diagnosing vocal function and disorder has been the focus of previous research. However, detailed analysis of factors that affect reliability and consistency of perceptual ratings of laryngoscopic footage has not been investigated in voice therapy outcome studies. This study evaluated clinicians’ judgments of the effectiveness of training differentiated vocal tract control of false vocal fold activity (FVFA), true vocal fold mass (TVFM) and larynx height (LH). A within-subject, experimental design was used to assess participants’ mastery in manipulating FVFA, TVFM, and LH assessed via laryngoscopic visualization of the larynx. Three experienced speech pathologists rated the nasendoscopy footage with accompanying acoustic recordings of 12 speakers. Intrajudge consistency, interjudge reliability, and interjudge agreement of perceptual ratings were investigated. Twelve vocally trained unimpaired speakers used differentiated biomechanical manipulation of various laryngeal muscles to produce eight specific vocal qualities each. These manipulated vocal qualities were rated by three experienced voice clinicians who demonstrated higher levels of intrajudge consistency and interjudge agreement when identifying rather than quantifying the degree of a voice quality based on their visual and auditory perceptions of the different vocal features. The findings suggest that unimpaired speakers can be trained successfully to manipulate and change individual biomechanical aspects of their vocal functions as demonstrated by the visual- and auditory-perceptual judgments of expert voice clinicians. These judgments are vulnerable to issues of reliability and suggests that judges used auditory-perceptual judgments when interpreting laryngoscopic footage, particularly when the view of laryngeal features is compromised.
from the Journal of Voice
CONCLUSION: Reverse phonation promoted a positive effect over the vibration of the mucosa of the vocal folds and over their stretching. This result suggests an effect over the vocal muscles, favoring changes of fundamental frequency; and over the homogenization and modification of mucus layer. Moreover, it promoted a global improvement of the vocal signal and of the sensations during its production.
Effects of voice training and voice hygiene education on acoustic and perceptual speech parameters and self-reported vocal well-being in female teachers
Voice education programs may help in optimizing teachers’ voice use. This study compared effects of voice training (VT) and voice hygiene lecture (VHL) in 60 randomly assigned female teachers. All 60 attended the lecture, and 30 completed a short training course in addition. Text reading was recorded in working environments and analyzed for fundamental frequency (F0), equivalent sound level (Leq), alpha ratio, jitter, shimmer, and perceptual quality. Self-reports of vocal well-being were registered. In the VHL group, increased F0 and difficulty of phonation and in the VT group decreased perturbation, increased alpha ratio, easier phonation, and improved perceptual and self-reported voice quality were found. Both groups equally self-reported increase of voice care knowledge. Results seem to indicate improved vocal well-being after training.