Computed fingertip touch for the instrumental control of musical sound with an excursion on the computed retinal afterimage

In this thesis, we present an articulated, empirical view on what human music making is, and on how this fundamentally relates to computation. The experimental evidence which we obtained seems to indicate that this view can be used as a tool, to systematically generate models, hypotheses and new technologies that enable an ever more complete answer to the fundamental question as to what forms of instrumental control of musical sound are possible to implement. This also entails the development of two novel transducer technologies for computed fingertip touch: The cyclotactor (CT) system, which provides fingerpad-orthogonal force output while tracking surface-orthogonal fingertip movement; and the kinetic surface friction transducer (KSFT) system, which provides fingerpad-parallel force output while tracking surface-parallel fingertip movement. In addition to the main research, the thesis also contains two research excursions, which are due to the nature of the Ph.D. position. The first excursion shows how repeated and varying pressing movements on the already held-down key of a computer keyboard can be used both to simplify existing user interactions and to implement new ones, that allow the rapid yet detailed navigation of multiple possible interaction outcomes. The second excursion shows that automated computational techniques can display shape specifically in the retinal afterimage, a well-known effect in the human visual system.Computer Systems, Imagery and Medi

Tangibility and Richness in Digital Musical Instrument Design

PhDThe sense of touch plays a fundamental role in musical performance: alongside hearing, it is the primary sensory modality used when interacting with musical instruments. Learning to play a musical instrument is one of the most developed haptic cultural practices, and within acoustic musical practice at large, the importance of touch and its close relationship to virtuosity and expression is well recognised. With digital musical instruments (DMIs) – instruments involving a combination of sensors and a digital sound engine – touch-mediated interaction remains the foremost means of control, but the interfaces of such instruments do not yet engage with the full spectrum of sensorimotor capabilities of a performer. This poses compelling questions for digital instrument design: how does the nuance and richness of physical interaction with an instrument manifest itself in the digital domain? Which design parameters are most important for haptic experience, and how do these parameters affect musical performance? Built around three practical studies which utilise DMIs as technology probes, this thesis addresses these questions from the point of view of design, of empirical musicology, and of tangible computing. In the first study musicians played a DMI with continuous pitch control and vibrotactile feedback in order to understand how dynamic tactile feedback can be implemented and how it influences musician experience and performance. The results suggest that certain vibrotactile feedback conditions can increase musicians’ tuning accuracy, but also disrupt temporal performance. The second study examines the influence of asynchronies between audio and haptic feedback. Two groups of musicians, amateurs and professional percussionists, were tasked with performing on a percussive DMI with variable action-sound latency. Differences between the two groups in terms of temporal accuracy and quality judgements illustrate the complex effects of asynchronous multimodal feedback. In the third study guitar-derivative DMIs with variable levels of control richness were observed with non-musicians and guitarists. The results from this study help clarify the relationship between tangible design factors, sensorimotor expertise and instrument behaviour. This thesis introduces a descriptive model of performer-instrument interaction, the projection model, which unites the design investigations from each study and provides a series of reflections and suggestions on the role of touch in DMI design.Doctoral Training Centre for Media and Arts Technolog