Sonification and the Interaction of Perceptual Dimensions: Can the Data Get Lost in the Map?                                    

John G. Neuhoff                     Gregory Kramer               Joseph Wayand
Department of Psychology            Metta Foundation             Department of Psychology
Lafayette College                   310 NW Brynwood Lane         Kent State University
Easton, PA, 18042-1781              Portland, OR 97229           Kent, OH 44242
+1 610 330 5287                     +1 503 292 8550              +1 330 672 7834
neuhoffj@lafayette.edu              greg@metta.org               jwayand@kent.edu


ABSTRACT                                                                                          
Many sonification techniques use acoustic attributes such as frequency, intensity, and timbre to represent different
characteristics of multidimensional data.  Here we demonstrate a perceptual interaction between changes in pitch and
loudness, as well as perceived asymmetries in directional change.  Three experiments show that changes in loudness can
influence judgments of pitch change, changes in pitch can influence loudness change, and that increases in loudness are
judged to change more than equivalent decreases.  Within a sonification of stock market data, these characteristics created
perceptual distortions in the data set.  The results imply that in situations where precision is critical, caution should be
exercised when using lower level acoustic dimensions such as frequency and intensity to represent multidimensional data.

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