Vocal problems among teachers: a review of prevalence, causes, prevention, and treatment

Voice disorders are thought to be one of the major occupational hazardsof school teaching. The resulting symptoms can affect teachers' ability to function in the classroom and prevent them from developing effective working relationships with other staff and students. Sick leave, speech pathology management, and surgical intervention can be costly. Severe voice problems can also result in a teacher permanently leaving the classroom. Despite the significant implications of voice disorders for teachers, this review of published research demonstrates that findings concerning the prevalence of voice problems in teachers and the causes and contributing factors of those voice problems are inconclusive. Similarly, previous research on the efficacy of prevention programs and treatment of voice problems in teachers provide few firm conclusions. Further research based on sound empirical data is needed, as many past studies have relied on anecdotal or self-report data. More operational definitions of what constitutes a voice disorder and the associated contributing factors should be adopted, along with the use of more instrumental measures and careful attention to methodology and appropriate statistical analyses. Only then will we have a sound basis for the development of effective prevention and education programs for teachers.     

Prevalence of voice problems in teachers

Teachers are frequently cited as experiencing a high rate of vocal dysfunction (1–7). Despite considerable research in the area of voice problems in teachers, the prevalence of voice disorders in this group is unknown. This study investigated the prevalence of self-reported voice problems in teachers using a mail survey of a simple random sample of 1168 state school teachers (preschool-Grade 12) in South Australia. As part of the survey, teachers were asked to report voice problems for the day of the survey, during the current teaching year, and during their careers. The response rate was 75%, with 16% of teachers reporting voice problems on the day of the survey, 20% reporting problems during the current teaching year, and 19% reporting problems at some time during their career. Females were twice as likely as males to report voice problems. These findings clearly indicate a need for further investigation of the causes of vocal dysfunction in teachers and for the development of educational programs aimed at preventing voice problems in this group of professional voice users.     

Changes in the Prevalence of Vocal Symptoms Among Teachers During a Twelve-Year Period

Vocal symptoms and voice disorders among teachers were studied in 1988 using a questionnaire designed to obtain information on six vocal symptoms that had appeared during the past 2 years. Twelve percent of the 478 respondents reported vocal symptoms occurring weekly or more often. The study was repeated using the same questionnaire in 2001. The results of this second study (n=241) indicate that vocal symptoms had increased considerably. Twenty-nine percent of the teachers reported symptoms occurring weekly or more often, and 20% reported two symptoms or more occurring at least once a week, which is significantly more than in 1988. Accordingly, voice disorders are probably a growing problem among teachers. Several factors may explain these increases. In 2001, the teachers complained more often about increases in the size of their classes. Factors that disturbed normal work routines, such as noisy or misbehaving pupils, had also increased significantly. A growing number of misbehaving pupils probably cause increased background noise and stress and, thus, increase the vocal symptoms in teachers.     

Frequency of voice problems among teachers and other occupations

This study describes the frequency of reporting vocal problems among a random sample of elementary and high school teachers (n = 554) compared to individuals working in other occupations (n = 220). Teachers were more likely to define themselves as ever having a voice problem (32% versus. 1 %, p < .05); having a tired, weak, or effortful voice (p < .05 each); and having a higher frequency of symptoms of physical discomfort with speaking (p < .05). They also were more likely to perceive that their voice problem negatively affected current job performance (p < .05) and limited options regarding change in work (p < .05). About 20% of teachers but only 4% of nonteachers had missed work due to their voice. These findings suggest that teachers are at highrisk for disability from voice disorders and that this health problem may have significant work-related and economic effects.     

Frequency and risk factors for voice problems in teachers of singing and control subjects

Using a questionnaire format, 125 teachers of singing and 49 control subjects indicated whether they had a current or past voice problem, and provided information about their demographic characteristics, voice use patterns, and medication use. The results revealed similar rates of current voice problems reported by the two subject groups. However, teachers of singing were considerably more likely to report ever having had a voice problem than controls (64 vs. 33%). Risk factors were similar for the two groups. Dehydrating medications and a report of a past voice problem both increased the likelihood of perceiving a current problem, by a factor of three and five, respectively. Females were twice as likely to report a past voice problem as males, and younger subjects were slightly more likely to report a past problem as compared with older subjects. The implications of the findings are discussed from a theoretical as well as pragmatic perspective.     

Prevalence of voice disorders in African American and European American preschoolers

Several studies have reported prevalence rates for voice disorders in school-aged children. Less is known, however, about such prevalence in preschoolers, and whether racial, ethnic, or cultural diversity may influence it. The presence of voice disorders in a total of 2445 African-American and European-American preschool children, 1246 males and 1199 females, from 2 to 6 years of age is reported here. Presence of a voice disorder characterized by hoarseness was identified by a three-prong approach including teacher identification, investigator screening, and parent identification. Speech-language pathologists listened individually to each child's speech as they engaged each child in play-conversation activities. A voice disorder was identified on the basis of the judgment of two speech-language pathologists. Voice disorders characterized by hoarseness were identified in 95 children or 3.9% of the total sample by the investigators. Statistical analysis revealed no significant differences for age, gender, or race.     

Vocal Problems Among Teachers: Evaluation of a Preventive Voice Program

Vocal education programs for teachers may prevent the emergence of vocal disorders; however, only a few studies have tried to evaluate the effectiveness of these preventive programs, particularly in the long term. Two hundred and sixty-four subjects, mostly kindergarten and primary school female teachers, participated in a course on voice care, including a theoretical seminar (120 minutes) and a short voice group therapy (180 minutes, small groups of 20 subjects). For 3 months, they had to either attend the vocal ergonomics norms and, as psychological reinforcement, they had to make out a daily report of vocal abuse, or to follow the given exercises for a more efficient vocal technique, reporting on whether the time scheduled was respected or not. The effectiveness of the course was assessed in a group of 21 female teachers through a randomized controlled study. Evaluation comprehended stroboscopy, perceptual and electro-acoustical voice analysis, Voice Handicap Index, and a course benefit questionnaire. A group of 20 teachers matched for age, working years, hoarseness grade, and vocal demand served as a control group. At 3 months evaluation, participants demonstrated amelioration in the global dysphonia rates (P=0.0003), jitter (P=0.0001), shimmer (P=0.0001), MPT (P=0.0001), and VHI (P=0.0001). Twelve months after the course, the positive effects remained, although they were slightly reduced. In conclusion, a course inclusive of two lectures, a short group voice therapy, home-controlled voice exercises, and hygiene, represents a feasible and cost-effective primary prevention of voice disorders in a homogeneous and well-motivated population of teachers.     

Voice handicap index change following treatment of voice disorders

Outcome measurements of voice disorders is an important new area for both the evaluation of voice-disordered patients and evaluation of treatment efficacy. The Voice Handicap Index (VHI) measures the patient's perception of the impact of his or her voice-disorder. The VHI was used in this study to measure the changes of the patient's perception following treatment for four different voice disorders. The VHI showed a significant change following treatment for unilateral vocal fold paralysis, vocal cyst/polyp, and muscle tension dysphonia. Results of this paper indicate that the VHI is a useful instrument to monitor the treatment efficacy for voice disorders.     

Mechanical and dynamic aspects of voice production as related to voice therapy and phonosurgery

Laryngeal framework surgery can change the position and tensionof the vocal folds safely without direct surgical intervention in the vocal fold proper. Some 23 years of experience with phonosurgery have proved its usefulness in treating dysphonia related to unilateral vocal fold paralysis, vocal fold atrophy, and pitch-related dysphonias. Meanwhile, much information about the mechanism of voice production has been obtained through intraoperative findings of voice and fiberscopic examination of the larynx . Based on such knowledge together with information obtained through model experiments, the human vocal organ was reconsidered mainly from the mechanical view point, and the roles of voice therapy and singing pedagogy were discussed in relation to phonosurgery. The vocal organ may not be an ideal musical organ and is rather vulnerable, but its potential is enormous.     

Perceived phonatory effort and phonation threshold pressure across a prolonged voice loading task: a study of vocal fatigue

Although the problem of vocal fatigue is not uncommon in people with voice disorders, research on objective quantifiable indicators of vocal fatigue is limited. It has been suggested that a speaker's perception of increased phonatory effort associated with periods of prolonged voice use is related to increased lung pressure required to initiate and sustain phonation. The purpose of this study was to examine the relationship among perceived phonatory effort (PPE), which was used as a subjective index of vocal fatigue, and phonation threshold pressure (PTP), a quantifiable measure defined as the minimal lung pressure required to initiate and sustain vocal fold oscillation. PTP and PPE were recorded before, during, and after five adult male and five adult female speakers engaged in a prolonged oral reading task designed to induce vocal fatigue. The results supported a direct, moderately strong relationship between PTP and PPE, particularly when PTP was measured during speech produced at comfortable and low-speaking pitch levels. No gender effects were found. PTP returned to baseline levels within 1 hour after the fatiguing task. PPE returned to baseline within 1 day. The data support the use of PTP as an objective index of vocal fatigue.     

Effects of sound-field frequency modulation amplification on reducing teachers'' sound pressure level in the classroom

Voice problems are a frequent difficulty that teachers experience. Common complaints by teachers include vocal fatigue and hoarseness. One possible explanation for these symptoms is prolonged elevations in vocal loudness within the classroom. This investigation examined the effectiveness of sound-field frequency modulation (FM) amplification on reducing the sound pressure level (SPL) of the teacher's voice during classroom instruction. Specifically, SPL was examined during speech produced in a classroom lecture by 10 teachers with and without the use of sound-field amplification. Results indicated a significant 2.42-dB decrease in SPL with the use of sound-field FM amplification. These data support the use of sound-field amplification in the vocal hygiene regimen recommended to teachers by speech-language pathologists.     

Effects of head extension and tongue protrusion on voice perturbation measures

Head extension with protruded tongue is the position for video-laryngoscopy and simultaneous glottographic recordings including photoglottographic signals. This study investigated the effect of head extension and tongue protrusion on the measures of fundamental frequency, frequency perturbation (jitter), and amplitude perturbation (shimmer). Acoustic signals recorded during sustained vowels were obtained from 49 women and 66 men with no speech or voice disorders in different head-tongue positions. Head extension was associated with increased fundamental frequency and decreased shimmer. In men, head extension did not appear to affect jitter. When the tongue was protruded, head extension tended to lower jitter. For both genders, tongue protrusion was associated with decreased fundamental frequency with head extension. In the men, tongue protrusion tended to increase shimmer when the head was in the neutral position. In the women, tongue protrusion was associated with increased jitter and increased shimmer and was most evident in the head-neutral position. These findings supported a physical linkage hypothesis of the relationship between vocal tract configuration and vocal fold vibration, suggesting that head-tongue position must be taken into account when comparing voice measures.     

A critical view of the yawn-sigh as a voice therapy technique

The purpose of this study was to take a critical look at a voice therapy technique known as the yawn-sigh. The voiced sigh as an approach in voice therapy has had increased use in recent years, particularly with problems of vocal hyperfunction. In this study, the physiology of the yawn-sigh was studied with video nasoendoscopy in eight normal subjects; their taped voices were also studied acoustically for possible fundamental frequency and formant changes in producing selected vowels under normal and sigh conditions. Although each subject was given a model by the examiner of a yawn-sigh, one of the eight subjects could not produce a true yawn-sigh. Endoscopic findings for seven of the eight subjects performing the yawn-sigh demonstrated retracted elevation of the tongue, a lower positioning of the larynx, and a widened pharynx. Acoustic analyses for the seven subjects producing the sigh found a marked lowering of the second and third formants. Implications for using the yawn-sigh in voice therapy are given, such as using a modified “silent” yawn-sigh, as an easy method for producing greater vocal tract relaxation.     

The Prevalence of Voice Disorders Among Day Care Center Teachers Compared with Nurses: A Questionnaire and Clinical Study

The acceptance of voice disorders by day care center teachers as an occupational disease is not an invariably established practice. This is due to the lack of reliable evidence of a higher risk for voice disorders in this profession. To find out the risk of voice disorders, an epidemiological study was conducted among day care center teachers (n = 262), using hospital nurses (n = 108) as a control group. Symptoms were charted by a questionnaire. In a clinical examination made by a laryngologist, the voice quality was assessed and the laryngeal status noted. Teachers at day care centers had significantly more voice disorders than did nurses. Vocal nodules and laryngitis findings appeared significantly more frequently among day care center teachers than among those in the control group. The results prove voice disorders to be more frequent among day care center teachers than among control group subjects, and also that the main cause for this may be a higher vocal loading among day care center teachers than among control group subjects.     

Expanding perspectives in care of the speaking voice

The effective voice clinician has always had to borrow from various disciplines: voice science, otolaryngology, psychology, and speech-language pathology. Such eclecticism requires, however, that the clinician integrate the perspectives of these various disciplines into some kind of theoretical clinical bias. One bias might be that with greater use of instrumentation in voice therapy, the voice clinician must not substitute data collection for attending to the feelings of the patient. By using the clinical input from various disciplines, for example, voice clinicians might develop a useful clinical perspective that vocal hyperfunction is one of the primary causes of many voice disorders. Consequently, from such a clinical view might come a treatment perspective that can clearly define the problem (too much effort while speaking) and offer a rationale for voice remediation.     

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.     

The Impact of Voice Disorders Among Teachers: Vocal Complaints, Treatment-Seeking Behavior, Knowledge of Vocal Care, and Voice-Related Absenteeism

Objectives

Teachers are at increased risk for developing voice disorders. Occupational risk factors have been extensively examined; however, little attention has been paid to the consequences of the vocal complaints. The objective of this study was to investigate the knowledge that teachers have about vocal care, treatment-seeking behavior, and voice-related absenteeism.

Methods

The study group comprised 994 teachers and 290 controls whose jobs did not involve vocal effort. All participants completed a questionnaire inquiring about vocal complaints, treatment-seeking behavior, voice-related absenteeism, and knowledge about vocal care. Comparisons were made between teachers with and without vocal complaints and with the control group.

Results

Teachers reported significantly more voice problems than the control population (51.2% vs 27.4%) (χ² = 50.45, df = 1, P < 0.001). Female teachers reported significantly higher levels of voice disorders than their male colleagues (38% vs 13.2%, χ² = 22.34, df = 1, P < 0.001). Teachers (25.4%) sought medical care and eventually 20.6% had missed at least 1 day of work because of voice problems. Female teachers were significantly more likely to seek medical help (χ² = 7.24, df = 1, P = 0.007) and to stay at home (χ² = 7.10, df = 1, P = 0.008) in comparison with their male colleagues. Only 13.5% of all teachers received information during their education.

Conclusions

Voice disorders have an impact on teachers' personal and professional life and imply a major financial burden for society. A substantial number of teachers needed medical help and was obligated to stay at home because of voice problems. This study strongly recommends the implementation of vocal education during the training of teacher students to prepare the vocal professional user.     

Changes in sustained production tasks among women with bilateral vocal nodules before and after voice therapy

The purpose of the current study was to determine how maximum phonationduration (MPD) of five notes (C4, D4, E4, F4, 134) sustained on /o/, sustained vowels (/i/, //, /a/, /u/), and s/z ratio (sustained /s/ and /z/ changed during voice therapy for vocal nodules. Voices of adult females before treatment and after resolution of vocal nodules were analyzed via the PM Pitch Analyzer. Treatment included tension reduction, abuse identification and elimination, laryngeal strengthening, and home exercises. Results indicate there was no significant difference in maximum phonation duration or S/Z ratio before and after treatment. Results revealed that females with vocal nodules demonstrate measurements before therapy similar to measures considered to be normal in persons without vocal nodules. Application of findings to clinical practice is discussed.