Cardiovascular response patterns and speech: a study of air traffic controllers

The present study examined the relationship between cardiovascular (CVS) response and speech among air traffic controllers (ATCs). During two one-hour work sessions continuous EKG, ear pulse, and audio recordings were obtained individually from 24 male ATCs. In one session the controller actively controlled aircraft, while in the other he worked in a support/coordinator position. Session time in both conditions was partitioned on the basis of audio recordings into four mutually exclusive activities: Radio/Phone Talk, Radio/Phone Listening, Casual Talk, and Silence. Change in cardiovascular response pattern as a function of these activities, as well as the influence of a series of moderator variables on cardiovascular response, was assessed by examining heart rate (HR) and the EKG R-wave to ear pulse interval (RPI) relative to a pre-session baseline. The RPI index was employed as a means of unobtrusively tracking blood pressure on a beat-by-beat basis. Although reliable, the overall changes in CVS response were modest. Speech-associated reactivity was expressed exclusively by the RPI index. HR changes were not evident in response to speech, rather, the HR index appeared to be most sensitive to situational demand. Discrepancies between the present pattern and magnitude of speech-associated CVS response and those reported previously are discussed in terms of the nature of speech in laboratory versus field settings and measurement methodologies.