The efficacy of traditional and physiological
biofeedback methods for modifying abnormal speech breathing patterns was investigated in a child with persistent
dysarthria following severe
traumatic brain injury (TBI). An A-B-A-B single-subject experimental research design was utilized to provide the subject with two exclusive periods of
therapy for speech breathing, based on traditional
therapy techniques and physiological
biofeedback methods, respectively. Traditional
therapy techniques included establishing optimal posture for speech breathing, explanation of the movement of the respiratory muscles, and a hierarchy of non-speech and speech tasks focusing on establishing an appropriate level of sub-glottal air pressure, and improving the subject's control of inhalation and exhalation. The
biofeedback phase of
therapy utilized variable inductance plethysmography (or Respitrace) to provide real-time, continuous visual
biofeedback of ribcage circumference during breathing. As in traditional
therapy, a hierarchy of non-speech and speech tasks were devised to improve the subject's control of his respiratory pattern. Throughout the project, the subject's respiratory support for speech was assessed both instrumentally and perceptually. Instrumental assessment included kinematic and spirometric measures, and perceptual assessment included the Frenchay
Dysarthria Assessment, Assessment of Intelligibility of Dysarthric Speech, and analysis of a speech sample. The results of the study demonstrated that real-time continuous visual
biofeedback techniques for modifying speech breathing patterns were not only effective, but superior to the traditional
therapy techniques for modifying abnormal speech breathing patterns in a child with persistent
dysarthria following severe TBI. These results show that physiological
biofeedback techniques are potentially useful clinical tools for the remediation of speech breathing impairment in the paediatric dysarthric population.