Effects of Instruction Method on Vital Capacity and Maximum Sustained Phonation in Adult Female Controls

Abstract

Angela Ohlhaut. Effects of Instruction Method on Vital Capacity and Maximum Sustained Phonation in Adult Female Controls (Under the direction of Kathleen T. Cox, Ph.D.) Department of Communication Sciences and Disorders, May 2012. The collection of aerodynamic measurements including vital capacity and maximum sustained phonation is common practice in Speech-Language Pathology to aid in the assessment and treatment of vocal dysfunction. Current research lacks information regarding the ideal instructions to be given to a patient about how to exhale for vital capacity or what type of feedback is reasonable to provide to a patient during maximum sustained phonation collection. The purpose of this study is to determine the effect of instruction and visual feedback during the collection of vital capacity and maximum sustained phonation tasks, respectively. Fifty female participants were included in this study. Each participant performed a total of 12 maximum sustained phonation tasks. 6 trials were conducted while sustaining the vowel /i/, and 6 trials during the vowel /a/. For each vowel sound /i/ and /a/, 3 trials received visual feedback from the examiner during collection and 3 did not. Each participant also performed 6 vital capacity tasks. Participants were instructed to exhale utilizing a "slow" exhalation for half the trials (8-10 seconds) and a "fast" exhalation (3-6 seconds) for the other half. The order of maximum sustained phonation and vital capacity tasks was randomized for each patient. Descriptive analyses of the data revealed that instruction and visual feedback provided no practical significance in predicting length of maximum sustained phonation or amount of air exhaled during vital capacity collection.