Factors Influencing the Performance Advantage of Speech Technology

This report addresses two factors that potentially influence the use of auditory displays and speech responses in a time-sharing environment. (1) S-C-R compatibility is proposed as a condition of enhanced performance when a verbal task employs the auditory/speech (A/S) modes and a spatial task employs the visual/manual (V/M) modes of input and output. (2) Task interference is enhanced to the extent that tasks performed concurrently compete for common input and output modes. An experiment is described in which a tracking task (V/M) is time-shared with a Sternberg Memory Search Task employing all four i/o combinations. As predicted by factor (2), dual task interference increased as a function of shared modalities between tasks. An asymmetry of interference effects was observed such that tracking was most disrupted by common output channels while RT was disrupted by common input modes.