Using Psychophysics to Design Speech Warnings

Abstract

An experiment is reported which applies psychophysical scaling techniques to the design of speech warnings. Participants used magnitude estimation to rate the perceived urgency of computer generated warning signal words (Deadly, Danger, Warning, Caution, Note) that varied systematically in speed. Stevens (1957) Power Law was used to model the relationship between changes in the acoustic parameter and changes in the perceived urgency of a particular signal word. The value for warning designers of the power function exponent, which quantifies and predicts the effect of acoustic changes on perceived urgency, is discussed.