The effects on decision task performance of computer synthetic voice output

Abstract

Computer-synthesized voice has reached technological maturity and is expected to help resolve some of the human-computer interface difficulties. Research was conducted which focused on the utility of adding computer voice output to a microcomputer work station for decision support. Specifically the computer voice duplicated instructions that were printed on the screen for a visual display task in order to facilitate “eyes on” the visual problem. Response time and the number of errors were compared with conditions without computer voice. Since cognitive style, or decision style, has been recognized as an important individual difference for interface design, subjects were classified as having an analytic, heuristic or neutral decision style. The results found a surprising interaction effect between decision style and computer synthetic voice. Response time and errors improved for the analytic subjects, were degraded for the heuristic subjects, and were unchanged for the neutral subjects. These findings are important for the design of the human-computer interface because 45% of the subjects were in the affected groups. This paper is thought to be the first evaluation of the effects of adding computer synthesized voice instructions to a computer work station for decision making.