Teachers are a population at high risk for voice disorders given their occupational demands. In a teaching career, a common debilitating symptom among all vocal symptoms experienced is - vocal fatigue. The impact of the experience of vocal fatigue is three fold, as this symptom: (a) predicts and leads to chronic voice problems, (b) affects occupational performance, and (c) impacts student learning and academic performance. Thus, vocal fatigue leads to a broader burden on healthcare costs of a chronic disorder, the economy of education [and the educator], and student learning. Although investigated in the voice literature, vocal fatigue lacks clarity in the definition, underlying mechanisms, and specific treatment or prevention approaches. A lack of such clarity can be attributed to the fact that vocal fatigue reflects a constellation of mechanisms which all manifest as tiredness of voice. On the contrary, fatigue is well documented in the exercise physiology literature including potential mechanisms and treatment options. We utilized principles from the well-described exercise physiology literature pertaining to the pattern of oxygen consumption and metabolic fuel used during task performance to examine the manifestation of vocal fatigue associated with a vocal task. Our preliminary data on potential mechanisms of vocal fatigue suggest two factors associated with this vocal symptom: 1) a greater reliance on anaerobic resources for fuel for vocal performance (i.e. less or no use of aerobic [oxygen] resources), and 2) poor physiological recovery from the vocal task. Vocally healthy cardiovascularly conditioned individuals showed greater reliance on oxygen resources during a vocal task and a more rapid recovery post task. Traditionally, voice production exercises are widely used to improve vocal skill and enhance neuromuscular efficiency to alleviate vocal fatigue. On the contrary, cardiovascular conditioning is widely used to increase endurance and decrease the early onset of fatigue in neuromotor task performance, but has not been systematically applied as a potential treatment for the problem of vocal fatigue. In a preliminary test, four-weeks of submaximal cardiovascular conditioning treatment in individuals with vocal fatigue (recruited using scores on the different factors of the Vocal fatigue Index-VFI) resulted in a shift in the metabolic source of fuel for a vocal task from predominantly anaerobic to greater aerobic resources in all three participants, with improvement of self-reported fatigue symptoms in 1 of 3 participants. Voice production exercises alleviated the symptoms of self-reported vocal fatigue in 2/3 participants. The proposed study's objective is (a) to determine the influence of cardiovascular conditioning exercise on the physiology of vocal task performance, post task recovery and self-reported symptoms of vocal fatigue in comparison to voice production exercises and (b) to predict differential treatment options for vocal fatigue based on baseline scores on the VFI. We will recruit 52 female teachers with vocal fatigue, ages 21-45 years, to be randomized to one of the two study arms: submaximal continuous cardiovascular conditioning exercise regimen or voice production exercises regimen. In these individuals, pre- and post-intervention physiologic cost of speaking, pattern of oxygen uptake and recovery kinetics, and self-reported vocal fatigue will all be recorded to determine impact of cardiovascular conditioning compared to the voice production exercise group on the physiology of vocal task performance. The outcomes will be used (a) to inform the development of a cardiovascular conditioning regimen to enhance physiologic vocal task management, (b) to determine the differential impact of cardiovascular conditioning and voice production exercise on vocal task management and alleviation of vocal fatigue symptoms and (c) to predict differential treatment approaches based on baseline VFI scores.
Teachers are a population at high risk for voice disorders. A common debilitating symptom experienced by teachers is vocal fatigue, impacting teachers? occupational performance and increasing health care costs. It is imperative to identify potential treatment options to alleviate the experience of such symptoms. The purpose of the proposed project is to utilize a novel and an unintuitive approach, specifically, a body-system level cardiovascular conditioning protocol in comparison to voice production exercises to alleviate symptoms of vocal fatigue in female teachers.
