Sound synthesis and composition with compression-controlled feedback

This paper introduces a method of sound synthesis that is based on the use of automatic gain control (AGC) in a time-delayed feedback loop. The approach, which the author calls "Compressed Feedback Synthesis" (CFS), can be conceptualized as a special expansion of a generalized comb filter, where feedback gain can be unity or greater. The system can be expanded with additional processing in the feedback loop to create a highly flexible and sensually engaging sound materials. The use of CFS in the author's audiovisual composition Sinus Aestum is discussed, including specific solutions to the challenging of controlling such a system compositionally

Towards musical interaction : 'Schismatics' for e-violin and computer.

This paper discusses the evolution of the Max/MSP patch used in schismatics (2007, rev. 2010) for electric violin (Violectra) and computer, by composer Sam Hayden in collaboration with violinist Mieko Kanno. schismatics involves a standard performance paradigm of a fixed notated part for the e-violin with sonically unfixed live computer processing. Hayden was unsatisfied with the early version of the piece: the use of attack detection on the live e-violin playing to trigger stochastic processes led to an essentially reactive behaviour in the computer, resulting in a somewhat predictable one-toone sonic relationship between them. It demonstrated little internal relationship between the two beyond an initial e-violin ‘action’ causing a computer ‘event’. The revisions in 2010, enabled by an AHRC Practice-Led research award, aimed to achieve 1) a more interactive performance situation and 2) a subtler and more ‘musical’ relationship between live and processed sounds. This was realised through the introduction of sound analysis objects, in particular machine listening and learning techniques developed by Nick Collins. One aspect of the programming was the mapping of analysis data to synthesis parameters, enabling the computer transformations of the e-violin to be directly related to Kanno’s interpretation of the piece in performance

The ixiQuarks: merging code and GUI in one creative space

This paper reports on ixiQuarks; an environment of instruments and effects that is built on top of the audio programming language SuperCollider. The rationale of these instruments is to explore alternative ways of designing musical interaction in screen-based software, and investigate how semiotics in interface design affects the musical output. The ixiQuarks are part of external libraries available to SuperCollider through the Quarks system. They are software instruments based on a non- realist design ideology that rejects the simulation of acoustic instruments or music hardware and focuses on experimentation at the level of musical interaction. In this environment we try to merge the graphical with the textual in the same instruments, allowing the user to reprogram and change parts of them in runtime. After a short introduction to SuperCollider and the Quark system, we will describe the ixiQuarks and the philosophical basis of their design. We conclude by looking at how they can be seen as epistemic tools that influence the musician in a complex hermeneutic circle of interpretation and signification

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 140

This bibliography lists 306 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1975

Sound feedback control model for live electronic performance in the Ecos Study

Through the Ecos Study we investigate possibilities for musical structuring based on theories of emergence, finding a fertile territory for experimentations within Agostino Di Scipio's paradigm of Audible Ecosystems. The inclusion of the acoustic environment as an active component of the musical system led us to rethink classical techniques of sound synthesis and modelling, some traditional models of electroacoustic performance, and to criticize the very role of interactions in a qualitative perspective. A positive feedback control model has been developed aiming at understanding the behaviour and the structure of the ecosystem supporting the implementation of the Spatial Instrument, a core element implemented through MAX/MSP patch and that offers a logical rationale for organizing speakers and microphones in the acoustic space. We introduce the underlying theoretical debate and present the feedback control mechanism as the basis from which the Spatial Instrument is developed

Index to NASA Tech Briefs, January - June 1967

Technological innovations for January-June 1967, abstracts and subject inde