Searching for attractors in speech and nonspeech respiration

Abstract

Our recent study of breathing during speech revealed that a nonlinear equation, originally proposed as a description of respiration during quiet breathing, may also provide a description of respiratory behavior during speech. This equation interrelates variables such as lung volume, airway resistance, and the duration of the utterance, and captures commonalities in the basic organization of the respiratory system during what have been considered different tasks or modes of behavior (i.e., speech and nonspeech). Further explorations of these data suggest that the mechanism underlying the behavior may be viewed as an attractor, possibly chaotic. The presence of such an attractor in respiratory patterns is supported by the findings of other researchers and is consistent with the adaptive nature of the system during speech and nonspeech tasks [e.g., M. P. Sammon and E. N. Bruce, J. Appl. Physiol. 70(4), 1748–1762 (1991)]. Descriptions of the attractor and some of its characteristics will be presented.