Mrs. Davies, a 55-year-old voice teacher and community theater director, came to our clinic complaining of hoarseness, vocal fatigue and throat pain that had worsened suddenly in the past two weeks. Videolaryngostroboscopy revealed a left vocal-fold hemorrhagic polyp, a right-fold localized hemorrhage and reflux.

In a case such as this, with obvious behavioral contributors, what's the best course of treatment? Offer surgery? Advise voice rest? Prescribe anti-reflux medicine? Educate the patient about voice health? Recommend voice treatment?

The answer may be none of these—alone.

Providers and their clients must combine treatment strategies to achieve the best results. For proof, look no further than a population of workers who can't do their job without a voice: our nation's teachers. An estimated five to 10 percent of Americans rely on the voice as their primary tool of trade, report Ingo Titze and colleagues in the Journal of Voice in 1997. And at almost 4 million, teachers make up most of this group.

The teaching profession can be hazardous to vocal health: Teachers tend to burden their voices by speaking loudly for long periods without sufficient rest or recovery. Complicating the problem are noisy classrooms; repeated exposure to upper respiratory infections; and inhalation of airborne irritants, including mold, dust and other air pollutants.

To help ease this voice burden on teachers, many speech-language pathologists advocate vocal hygiene—educating teachers about voice preservation measures like pacing and resting. Such education is critical in voice treatment, but outcome studies indicate that more intervention is needed once a teacher's voice is affected: Vocal function exercises, resonant therapy and amplification play key roles in voice rehabilitation.

Scope of the problem

Teachers spend much of their time delivering lessons, reading aloud and directing children. So it's not surprising that 11 percent of them report a current voice disorder, and 58 percent report a history of a voice disorder, as we found in research we published in the Journal of Speech, Language, and Hearing Research in 2004. Our research also found that vocal dysfunction interferes with job satisfaction, performance and attendance, causing 18 percent of teachers to miss work, and 40 percent of them to limit classroom activities.

Compared with the general population, teachers are more likely to consult a medical professional regarding a voice disorder and to consider a career change due to voice-related dysfunction. Laryngeal discomfort, increased effort during voice use, vocal fatigue and difficulty projecting the voice contribute disproportionately to voice-related work disruption and absenteeism. Because of lost workdays and treatment expenses, the societal costs in the United States alone have been estimated at a staggering $2.5 billion annually by Katherine Verdolini and Lorraine Ramig in their 2001 article in Logopedics, Phoniatrics, Vocology.

Furthermore, teachers who specifically engage in vocally intense activities—such as loud talking and singing—for extended periods are at greatest risk for developing voice disorders. This group includes teachers of vocal music, drama and the performing arts, with vocal music teachers at the greatest risk, as reported in research led by Susan Thibeault in the Annals of Epidemiology in 2004. In contrast, special and vocational education teachers, who typically have small classes, report the fewest voice problems. In addition, it's important to note that students' learning suffers when they cannot hear and understand their teachers.

Voice fixes

Until recently, little was known about which voice treatments can best help teachers. To find answers, we've conducted several randomized clinical trials with teachers over the past decade. In the first study, we compared the effectiveness of vocal hygiene instruction and vocal function exercises with nontreatment. In vocal hygiene, we aim to reduce vocal fold tissue injury and facilitate recovery by eliminating unhealthy behaviors—such as loud shouting—and replacing them with healthier practices, such as reducing background noise and moving closer to listeners when speaking.

In vocal function exercises, we systematically aim to strengthen and rebalance the subsystems involved in voice production: respiration, phonation and resonance. As reported in the Journal of Speech, Language, and Hearing Research in 2001, our study results show that only teachers who adhere to the exercise program report a significant benefit. Thus, vocal hygiene alone is not sufficient to reverse an already established voice disorder. Exercises appear key to making that happen.

In a second trial, we compared the effects of portable voice amplification and voice hygiene instruction. As published in the Journal of Speech, Language, and Hearing Research in 2002, we found that only the amplification group experienced significant reductions in mean scores on the Voice Handicap Index, which assesses voice-related functioning and quality of life. Other research has confirmed the benefits of voice amplification for teachers and students, who report that it aids their learning and concentration.

In the final trial, we compared the effects of voice amplification with two other interventions: resonance therapy and respiratory muscle training. In resonant voice therapy, we train the teacher to produce voice sounds in an easier, more resonant way. The goals are to achieve the strongest possible voice with minimal effort and to reduce impact stress on the vocal folds, thus minimizing chances of injury. In respiratory muscle training, we use an expiratory pressure threshold training device to help teachers bolster their expiratory muscle strength. The technique is designed to help patients generate sufficient subglottal pressures for voice production, easing potentially harmful effects on the larynx.

The results, published in the Journal of Speech, Language, and Hearing Research in 2003, reveal that only the teachers who receive amplification or resonance therapy report significant reductions in mean Voice Handicap Index scores. These findings replicate results from the earlier clinical trial confirming the efficacy of amplification, and provide new evidence to support resonance therapy as an effective treatment for voice problems in teachers. Since this randomized trial, more published studies have supported resonance therapy as a stand-alone treatment or in combination with other treatment approaches, including voice hygiene instruction and vocal function exercises.

The prevention question

Despite the prevalence of voice problems among teachers, teacher training programs rarely provide instruction in care and preservation of the voice. Although voice hygiene instruction early in a teacher's career makes intuitive sense, using it as a primary means of preventing voice disorders is controversial. Disease prevention research suggests a schism between possessing knowledge about healthy practices and actually incorporating such practices into daily routines and making them habitual.

Several recent studies have evaluated the preventive effects of voice care approaches in preservice and public school music teachers, and confirmed that such indirect approaches are relatively ineffective unless combined with direct, individualized vocal training. This sort of one-on-one instruction and periodic, careful monitoring seem necessary to establish behaviors that prevent voice problems.

Other unresolved issues in primary prevention concern whether highest-risk teachers—versus all teachers—should be targeted for intervention, and whether student teachers and new hires should receive baseline screening for voice disorders and periodic screenings thereafter. Perhaps most important, who is responsible for designing, implementing, funding and tracking the effectiveness of such prevention programs?

Meanwhile, school teachers represent the highest-volume and highest-risk occupation for voice disorders. And the research suggests that, when it comes to treatment, direct behavioral interventions are necessary. Let's return to the case of Mrs. Davies, the 55-year-old voice teacher and community theater director with worsening hoarseness and vocal fatigue. She received four sessions of voice treatment, including manual circumlaryngeal techniques, vocal function exercises and resonant therapy. And she practiced these techniques at home. Her follow-up evaluation revealed resolution of the polyp and reduced voice symptoms. Ultimately, her voice returned to normal and she happily returned to her studio—to help her music students' voices soar.

This article is adapted from the November 2010 issue of Perspectives on Voice and Voice Disorders of ASHA Special Interest Group 3.