Date of Award

Summer 2007

Document Type

Thesis - Open Access

Degree Name

Master of Science in Human Factors & Systems


Human Factors and Systems

Committee Chair

Shawn Doherty, Ph.D.

Committee Member

Albert Boquet, Ph.D.

Committee Member

Peter Ragan, Ph.D.


The present study examines the effect of foreign accent interference with the ability to execute commands presented in speech format. The objective of this study was to demonstrate that a foreign accent influences performance. Participants were between 18 and 40 years of age. Half of the participants were native speakers of Spanish who began learning English as a second language via the classroom setting. The other half were native English-speaking with little or no exposure to the Spanish language. The experimental design was similar to an aviation scenario where participants listened to simulated ATC procedural commands and execute them on a simulated control panel. Response time (in milliseconds) and accuracy were recorded. Accuracy was measure by incorrect responses and false starts. Incorrect responses were measured when participants pressed an arrow key different from the commanded direction. False starts occurred when the participant pressed a key before the command was presented. The results of this study did not reveal an effect of language for reaction time. However, the false start data indicated a significant effect on accent for native English speakers, but not an effect on accent for non-native English speakers. On the contrary, the data from incorrect responses does not show a significant effect of accent for native English speakers but a significant difference in effect of accent on non-native English speakers. Therefore, the accuracy hypotheses were not supported.