Analyzing journeys in sound: usability of graphical interpolators for sound design

Abstract

Graphical interpolation systems provide a simple mechanism for the control of sound synthesis by providing a level of abstraction above the engine parameters, allowing users to explore different sounds without awareness of the underlying details. Typically, a graphical interpolator presents the user with a two-dimensional pane where a number of synthesizer presets, each representing a collection of synthesis parameter values, can be located. Moving an interpolation cursor within the pane results in the calculation of new parameter values, based on its position, the relative locations of the presets, and the mathematical interpolation function, thus generating new sounds. These systems supply users with two sensory modalities in the form of sonic output and visual feedback from the interface. A number of graphical interpolator systems have been developed over the years, with a variety of user-interface designs, but few have been subject to formal user evaluation. Our testing studied both user interaction with, and the perceived usability of, graphical interpolation systems by comparing alternative visualizations in order to establish whether the visual feedback provided by the interface aids the locating of sounds within the space. The outcomes of our study may help to better understand design considerations for graphical interpolators and inform future designs.