Effects of Biofeedback on Vocal Behavior on a Child with a Unilateral Vocal Fold Lesion

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At any given time, 3-9% of the general population experiences a voice problem. The incidence of voice disorders in children can vary anywhere between 6 and 23%, yet, only 2-4% of the population are seen by speech-language pathologists for further assessment and treatment. Voice disorders have negative effects on the social, emotional, and physical functioning of the child. Unfortunately, there is little known about the appropriate management of children with voice disorders. Depending on the nature of the voice disorder, different approaches, including behavioral voice therapy, vocal hygiene management, or medical intervention, are available. However, a concern with behavioral voice therapy is the ability of the child to transfer skills learned in clinic to an outside setting - limiting generalization and adaptation of the new behavioral approach. Biofeedback has been successfully used in adults with voice disorders to help generalize new vocal behaviors. Such data is lacking in the treatment of voice problems in the pediatric population. The current case study aimed to understand the use of biofeedback in an eight-year-old male who was diagnosed with a unilateral vocal fold lesion, who exhibited difficulty maintaining and generalizing his new vocal behaviors. It was hypothesized that the child would benefit from biofeedback and would maintain new vocal behaviors including the use of a safe and efficient voice pattern outside the clinic setting. Longitudinal data on vocal parameters including the pitch, loudness, and vocal fold vibration were obtained over a period of five weeks using an ambulation phonation monitor (APM). The APM uses an accelerometer attached to the sternal notch and measures pitch, loudness, and vocal fold vibration, which helps determine an individual’s daily voice use pattern and thereby determines the appropriate biofeedback setting. The five week period included (a) a week of pretesting, (b) two weeks of biofeedback, (c) a week of post-testing immediately following the week of biofeedback, and (d) a generalization testing two months post-study. During the five-week period, vocal parameters were monitored for an average of 7- 10 hours for 2-3 days each week. On weeks two and three, the child was provided with biofeedback on loudness levels based on his data from the pretesting week. Results indicated change in vocal parameters including loudness and vocal fold vibration patterns during the weeks of biofeedback. However, such generalization was not observed neither during immediate post feedback monitoring nor two months following the study protocol. Such data provide immediate effects from biofeedback on vocal behavior, however, motor learning principles, dose, and frequency of biofeedback will be discussed to further understand the long-term effects of biofeedback in children with voice problems.


Johnson City, TN

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