The equivalence of visual and auditory graphical displays was examined in two experiments. In Experiment 1, multidimensional scaling techniques were applied to paired comparison similarity judgments of both auditory and visual displays of simple periodic wave forms. In Experiment 2, a subset of perceptually similar pairs of wave forms was selected as the stimulus set for an AB-X discrimination task in both auditory and visual modalities. Results suggest much greater apparent visualauditory equivalence for the similarity rating task than for the more difficult discrimination task, implying that one should consider the demands of the task when deciding whether auditory graphic displays are suitable alternatives to more traditional visual displays.Advances in computer technology offer possibilities for data summary and presentation in highly nontraditional formats. Flowers and Hauer (1992, 1993, 1995 have demonstrated that the perceptual structures ofvision and audition are highly similar for the representation ofgraphs depicting statistical distribution and time series functions. The present investigation was designed to extend previous research to a new form ofdata: periodic wave forms.This project included both an assessment of visualauditory perceptual equivalence for these graphs (based on similarity ratings) and an assessment of the equivalence of accuracy performance for the two modalities on a more demanding AB-X discrimination task. If auditory displays are to be used as substitutes for visual graphics, it is necessary to assess the degree of accuracy achievable by the two modalities for demanding tasks such as discriminating between different data sets. Knowing the relative performance levels of the two modalities for such discriminations is useful in decisions about the appropriateness of auditory graphics in general, the optimal design of auditory displays, and the appropriate measures for training people to use them.
EXPERIMENT!In this study, we assessed whether the degree ofvisualauditory perceptual equivalence ofthese wave-form stimCorrespondenceshould be addressed to K. D. Turnage,Department of Psychology, 209 Burnett Hall, University of Nebraska, Lincoln, NE 68588-0308. uli would parallel the perceptual equivalence reported for other types of graphs. If wave-form data are as suitable for auditory presentation as distributional and trend data are, visual and auditory perceptions of these stimuli should be very equivalent.
MethodSubjects. Twenty-six undergraduate psychology students who reported having normal or corrected-to-normal vision and hearing participated to fulfill a course research requirement. Thirteen subjects (balanced for gender) participated in each modality condition.Materials. Eighteen data samples, each consisting of 100 numbers that described a periodic wave-form function, were computer generated. These 18 wave forms varied in shape (sine, square, and a composite, which was a weighted sum ofthe two), frequency (low, medium, and high, which were 4, 6, and 8 cycles per 100 points, re...