Nuance: Adding Multi-touch Force Detection to the iPad

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Perception of attributes in real and synthetic string instrument sounds

This thesis explores the perceptual features of natural and synthetic string instrument sounds. The contributions are in formal listening experiments on a variety of features in musical sounds that have not been studied in detail previously. The effects of inharmonicity on timbre and pitch have been measured. The results indicate that the implementation of inharmonicity is not always necessary. The timbre effect is more salient in natural instruments, but for high tones a pitch difference may also be detected. Guidelines were given for compensation of the pitch effect. A perceptual study of the decaying parameters showed that large deviations from the reference value are tolerated perceptually. The studies on the audibility of initial pitch glides and dual-polarization effects provides practical knowledge that helps in the implementation of these features in digital sound synthesis. Related to expression rather than basic string behavior, the study on perception-based control of the vibrato parameters has a sligthly different background. However, all of the studied features are more or less player-controlled by different ways of plucking the string or pressing the key. The main objective of the thesis is to find answers to current problems in digital sound synthesis, such as parameter quantization. Another aim is to gain more general understanding of how we perceive musical sounds.reviewe

Physically-based auralization : design, implementation, and evaluation

The aim of this research is to implement an auralization system that renders audible a 3D model of an acoustic environment. The design of such a system is an iterative process where successive evaluation of auralization quality is utilized to further refine the model and develop the rendering methods. The work can be divided into two parts corresponding to design and implementation of an auralization system and evaluation of the system employing objective and subjective criteria. The presented auralization method enables both static and dynamic rendering. In dynamic rendering positions and orientations of sound sources, surfaces, or a listener can change. These changes are allowed by modeling the direct sound and early reflections with the image-source method. In addition, the late reverberation is modeled with a time-invariant recursive digital filter structure. The core of the thesis deals with the processing of image sources for auralization. The sound signal emitted by each image source is processed with digital filters modeling such acoustic phenomena as sound source directivity, distance delay and attenuation, air and material absorption, and the characteristics of spatial hearing. The digital filter design and implementation of these filters are presented in detail. The traditional image-source method has also been extended to handle diffraction in addition to specular reflections. The evaluation of quality of the implemented auralization system was performed by comparing recorded and auralized soundtracks subjectively. The compared soundtracks were prepared by recording sound signals in a real room and by auralizing these signals with a 3D model of the room. The auralization quality was assessed with objective and subjective methods. The objective analysis was based on both traditional room acoustic criteria and on a simplified auditory model developed for this purpose. This new analysis method mimics the behavior of human cochlea. Therefore, with the developed method, impulse responses and sound signals can be visualized with similar time and frequency resolution as human hearing applies. The evaluation was completed subjectively by conducting listening tests. The utilized listening test methodology is explained and the final results are presented. The results show that the implemented auralization system provides plausible and natural sounding auralizations in rooms similar to the lecture room employed for evaluation.reviewe

Being sound: FLOSS, flow and event in the composition and ensemble performance of free open computer music

This commentary describes my recent approach to writing compositions for the ensemble performance of computer music. Drawing on experimental music and improvisation, I contend that such music is best considered in terms of people’s situated and relational interplay. The compositional and performative question that permeates this thesis is ‘what can we do, in this time and space, with these tools available to us?’. As themes of equality and egalitarian access underpin this work throughout, I highlight my engagement with Free Libre Open Source Software (FLOSS) ideology and community, reflecting on how this achieves my aims. I describe my writing of text score compositions, making use of the term bounded improvisation, whose purposeful requirements for indeterminate realisation extends most current computer-based performance practice. Though no single strand of this research is perhaps unusual by itself, such an assemblage as that outlined above (incorporating composition, computer coding and ensemble performance practice) is, when allied to an understanding of electronic and computer music praxis, currently an underdeveloped approach. Such an approach I have thus chosen to term free open computer music. I incorporate two further pre-existing conceptual formulations to present a framework for constructing, reflecting on, and developing my work in this field. Firstly flow or 'immersed experience' is useful to explicate difficult to capture aspects of instrumental engagement and ensemble performance. Secondly, this portfolio of scores aims to produce well-constructed situations, facilitating spaces of flow which contain within their environments the opportunity for an event to take place. I present the outcomes of my practice as place-forming tactics that catalyse something to do, but not what to do, in performative spaces such as those described above. Such intentions define my aims for composition. These theoretical concerns, together with an allied consideration of the underpinning themes highlighted above, is a useful framework for refection and evaluation of this work

Establishing a laptop orchestra in South Africa : an emic-centred inquiry into computer music performance

Dissertation (MMus (Music Technology))--University of Pretoria, 2022.A few months into the final year of my undergraduate degree an opportunity emerged to oversee and coordinate the technical and organisational aspects of UPLOrc (University of Pretoria Laptop Orchestra), an ensemble of laptops consisting of undergraduate and post-graduate students whose focus is to explore collective live coding practices. In addition to coordinating the activities of UPLOrc, in April 2020 I was invited to collaborate with SuperContinent, a networked live coding ensemble whose members are located across various continents at a minimum distance of more than 500 kilometres apart. A qualitatively-driven mixed-methods research paradigm was implemented guiding the collection of data from multiple sources in order to obtain a broader understanding of the complexities involved with live coding in collaborative contexts. A netnographic methodology was chosen for the qualitative component of this research, and incorporated an intersecting secondary quantitative component in the form of a survey administered to members of the networked performance community. The research is presented from an emic (insider’s) perspective in the form of an autoethnographic account of my experiences as a performer and instructor of live-coded music. Adopting the perspective of an insider initiated a process of critical self-reflection in which I attempted to understand my role as a student, teacher and collaborator in both performance and educational contexts. The procedures implemented in this research prompted by my collaboration, communication, active participation, and performance with the members of both ensembles over a two-year period, have allowed me to realise the purpose and power of collaborative networked live coding in terms of its potential for cultivating transformative spaces for musical creativity. In addition, conducting this research has provided me with the opportunity to begin the process of building an identity as a live coder, an identity that is multifaceted, complex and constantly negotiated no matter the context in which it operates.MusicMMus (Music Technology)Unrestricte