Toward the design and evaluation of continuous sound in tangible interfaces: The Spinotron

This paper reports on an approach to the design of continuous sonic feedback in tangible interfaces, and on quantitative evaluation methods intended to guide such design tasks. The issues it addresses may be of central relevance to areas of the emerging discipline of sonic interaction design that have begun to address the unique problems of designing sound for highly interactive contexts. Three experiments were conducted to assess two key aspects of the sound design developed for an abstract object designed for these experiments, which we refer to as the Spinotron. First, a comparison of sound source identification was made between three cases: passive listening to temporally static sounds; passive listening to dynamically evolving sounds; and listening to sounds generated through active manipulation of the artifact. The results show that control over the sound production process influences the material of the objects in interaction identified as the source of the sounds. Second, in a learning experiment, users’ performance with the Spinotron device was compared between a group of participants that were provided only with passive proprioceptive information, and for another group who were also presented with synthetic sound produced by the artifact. The results indicated that the sound, when present, aided users in learning to control the device, whereas without the sound no learning was observed. Together, these results hold promise toward creating a foundation for the design of continuous sound that is intended to accompany control actions on the part of users, and toward establishing a basis for experimental/quantitative evaluation methods and gathering basic knowledge about sensory-motor activity engaged in tangible sonic interactions.