Respiratory and Laryngeal Function During Spontaneous Speaking in Teachers with Voice Disorders

Abstract

Purpose: The purpose of this study was to determine if respiratory and laryngeal function during spontaneous speech production were different for teachers with voice disorders as compared to teachers without voice problems. The basic research questions posed in this study, as assessed during spontaneous speaking were: 1) Do subjects with a voice disorder show differences in lung volume patterns relative to control subjects? 2) Do subjects with a voice disorder show differences in vocal fold approximation as measured by contact quotient and contact index relative to control subjects? 3) Are these between-group differences most pronounced for mock teaching tasks versus a conversational speaking task? 4) Do subjects with a voice disorder rely more on laryngeal versus respiratory-based strategies for increasing loudness level as compared to control subjects?Method: Nine teachers with and nine teachers without voice problems were included in this study. Respiratory function was measured with magnetometry, and laryngeal function was measured with electroglottography. Respiratory and laryngeal function were measured during three spontaneous speaking tasks: a simulated teaching task at a typical and increased loudness level, and a conversational speaking task. Two structured speaking tasks were included for comparison of electroglottography measures: a paragraph reading task and a sustained vowel.Results: Lung volume termination level in spontaneous speaking was significantly lower for the teachers with voice disorders relative to teachers without voice problems. Lung volume initiation level was lower for the teachers with versus without voice problems during teaching-related speaking tasks. Laryngeal function as assessed with electroglottography did not show between-group differences. Across tasks, the measure of contact index was lower (more negative) during the conversational speaking task as compared to the sustained vowel task, indicating greater contact phase asymmetry during vocal fold vibration.Conclusions: These findings suggest that teachers with a voice disorder use different speech breathing strategies than teachers without voice problems. Management of teachers with voice problems may need to incorporate respiratory training that alters lung volume levels during speaking. Future research is needed to determine whether altering such patterns results in improved voice parameters and self-perceived improvement in vocal symptoms.