ACCESSIBLE DIGITAL MUSICAL INSTRUMENTS FOR QUADRIPLEGIC MUSICIANS

This thesis explores a particular research topic in the field of Sound and Music Computing, dedicated to the creation of Accessible Digital Musical Instruments (ADMIs) designed for users affected by quadriplegia or similar motor impairments. With such conditions an user is completely paralyzed from the neck down. The impossibility to control the upper and lower limbs, particularly fingers, makes it impossible for such users to play conventional musical instruments, both acoustic and digital. This makes it necessary to introduce specific and non-trivial design and development solutions. A first part of the work is dedicated to the analysis of the related context. After defining the pertinent jargon, an analysis of different physical interaction channels available to people with quadriplegic disabilities is provided, with a review of the sensors suitable for their detection. Some of these channels are then evaluated through an experimental methodology. Further chapters provide an analysis of the state of the art in ADMIs for quadriplegic users, as well as design tools dedicated to ADMIs in general. A chapter is dedicated to the design of musical interfaces controlled through gaze, one of the most employed channels in this context. The second part describes the design, development and testing of new ADMIs suitable for quadriplegic users. The implementation of a software library for developing or fast-prototyping software instruments is described, as well as two Open-Source Hardware sensor peripherals developed ad-hoc for the detection of breath and head rotation. The remaining chapters describe the design, implementation and evaluation of Netytar, Netychords and Resin, three ADMIs that are played through the detection of gaze, breath, head movement, and stimulated resonances in the upper vocal tract, therefore playable hands-free.