The purpose of this study was to examine the bidirectional effects of simulated driving and conversations using different speaking modalities. Participants included 30 males and 30 females with no history of speech, language or hearing disorders. The participants were divided into three age groups: 20s, 40s, and 60s. They completed a driving simulation task in isolation and also while speaking on a hand-held or hands-free cell phone or with a passenger in the car. Speech measures included speaking time ratio, mean, and standard deviation of intensity, as well as mean and standard deviation of fundamental frequency in semitones. Driving measures included standard deviation of lane position, mean, and standard deviation of speed, standard deviation of steering wheel position, and the average number of steering wheel turns. There were significant effects of speaking while driving on mean intensity, speaking time ratio, standard deviation of steering wheel position, and the number of steering wheel turns. There were significant gender effects for speaking time ratio, standard deviation of intensity, and mean intensity, with the females having higher speaking time ratios, and the males having a higher standard deviation and mean of intensity. There was a significant age effect for mean fundamental frequency, standard deviation of lane position, and the standard deviation of steering wheel position. For mean fundamental frequency, the 60s group were lower than the 20s group. The 60s group had a higher standard deviation of lane position and standard deviation of steering wheel position. These findings reveal effects on both speaking and driving performance when speaking and driving concurrently. This has potential clinical implications for planning therapy activities that will help individuals generalize their learned skills from quiet, distraction-free clinic rooms to more realistic situations with distractions and background noise.
College and Department
David O. McKay School of Education; Communication Disorders
BYU ScholarsArchive Citation
Glenn, Katy, "Effects of Conversational Modalities on Driving and Speaking Performance" (2017). All Theses and Dissertations. 6294.
driving, speech acoustics, divided attention, bidirectional interference