Stockhausen’s graphically notated Pole für 2 was created for the multi-channel diffusion system in the spherical auditorium at the German pavilion at the Osaka World’s Fair in 1970. The work is remarkable for the way in which spatiality is explored through new developments in graphic notation – both for three-dimensional and sound projection, and to indicate musical imitation and transformation of short-wave radio signals. These two notational systems unite through the synchronous unfolding of time in Pole, and similarly through the spatial structure of auditorium’s architecture that housed over 50 loudspeakers in 6 layers. By using the sound projection score as the basis for the construction of a NURBS (non-uniform rational B-spline) model, each of the player’s sound projection geometries within the auditorium can be transmediated, thus allowing for a visual representation of the spatial design of the work. Examining the topology of the models produced from the work’s six sections further allows for emergent architectonic characteristics of volume, manifold and envelope to be tracked, thus pointing to Stockhausen’s characterisation of design space. The strong connection of the work to the auditorium’s spherical structure also points to the nature of the composer’s sound design as one predicated on the ability of patterns of sound projection to articulate tangible space, and therefore produce ephemeral aural architectures.

This article is an introduction to the specialised area of spatialised broadcasting experiments associated with radio art practices. This subject is investigated primarily from two perspectives: artistic works that explore the dissemination of radio waves (the ‘spectrumscape’) and the multichannel broadcasting/listening experience. It also discusses some of the history and ideas that form the undercurrents for radio art practice and explores radio art’s uses and concepts of spatiality.

In the context of current developments towards an exchange format for spatial audio, it is important to consider the interactions and tensions between spatial composition techniques and spatial audio technologies. This paper gives an overview of common compositional techniques and audio technologies used for spatial compositions, and discusses various forms of hybrid uses of audio technologies. A spatial composition created using certain audio technologies may lose integrity when transferred to another audio technology, when the compositional intent is not taken into account. Tools that are flexible with regard to the spatial audio reproduction technology applied are useful for the comparison of various spatialisation methods during the compositional process, but are also essential to enable a hybrid use of technologies within one composition.

The introduction of new techniques for audio reproduction such as HRTF-based technology, wave field synthesis and higher-order Ambisonics is accompanied by a paradigm shift from channel-based to object-based transmission and storage of spatial audio. Not only is the separate coding of source signal and source location more efficient considering the number of channels used for reproduction by large loudspeaker arrays, it also opens up new options for a user-controlled interactive sound field design. This article describes the need for a common exchange format for object-based audio scenes, reviews some existing formats with potential to meet some of the requirements and finally introduces a new format called Audio Scene Description Format (ASDF) and presents the SoundScape Renderer, an audio reproduction software which implements a draft version of the ASDF.

Listeners experience electroacoustic music as full of significance and meaning, and they experience spatiality as one of the factors contributing to its meaningfulness. If we want to understand spatiality in electroacoustic music, we must understand how the listener’s mental processes give rise to the experience of meaning. In electroacoustic music as in everyday life, these mental processes unite the peripheral auditory system with human spatial cognition. In the discussion that follows we consider a range of the listener’s mental processes relating space and meaning from the perceptual attributes of spatial imagery to the spatial reference frames for places and navigation. When considering multichannel loudspeaker systems in particular, an important part of the discussion is focused on the distinctive and idiomatic ways in which this particular mode of sound production contributes to and situates meaning. These include the phenomenon of image dispersion, the important consequences of the precedence effect and the influence of source characteristics on spatial imagery. These are discussed in close relation to the practicalities of artistic practice and to the potential for artistic meaning experienced by the listener.

This paper outlines some recent developments in multichannel composition at the Electroacoustic Music Studios, University of Birmingham and its performance wing, BEAST (Birmingham ElectroAcoustic Sound Theatre). In doing so it attempts to codify and define some emerging aspects of spatialisation practice which are found both within the BEAST community and beyond. The discussion covers software and techniques developed and adapted for use with BEAST, new and pragmatic approaches to composing for large-scale multichannel systems, such as n-channel composition and composing in ‘stems’, and issues arising from a resulting blurring between composition and performance practices.

Approaches to the multichannel spatialisation of electroacoustic music are described here with reference to musical case studies which focus upon the expressive functions of space and the theatricality of sound diffusion in an acousmatic context. A site-specific approach to spatialisation is proposed to enhance theatrical aspects of musical performance. Case studies include proposals for novel layouts of the diffusion system within the performance space and compositional techniques that are designed to re-evaluate our understanding of individual listening spaces.

This paper describes a new sound spatialisation system which is an integral part of Rensselaer Polytechnic Institute’s new Experimental Media and Performing Arts Center (EMPAC). The Cinematic Spatial Sound Display (CSSD) was originally conceived for interactive panorama video installations, but the architecture goes beyond this particular application. The CSSD is characterised by its scalability to various loudspeaker configurations. It spatialises sound from dry sound files or live sources using control data that describe the spatial scenes. The time lines for source positions and other experimental parameters can be stored and edited in the CSSD, and the system can also process live user input to control selected parameters. The CSSD is more than just a sound positioning tool, and the underlying Virtual Microphone Control (ViMiC) technology was developed to support artists in designing new forms of spatial imagery. The software enables the user to create computer-generated rooms with virtual microphones and sound sources. The algorithm uses physical laws to auralise acoustic scenes – allowing realistic effects such as the Doppler shift and the simulation of various classical microphone techniques. Various parameters of ViMiC can be adjusted in real time, including the directivity patterns and orientations of both the microphones and sound sources as well as their precise locations. Surreal scenes can be created by assigning artificial directivity patterns to microphones or changing the laws of physics in the model. An algorithm to extract the sound-source positions in recordings using a microphone array is also part of the CSSD. The algorithm was specifically designed to operate in multiple sound-source scenarios and can also be used for telematic music applications.

In this article we describe our ongoing research and development efforts towards integrating the control of sound spatialisation in computer-aided composition. Most commonly, the process of sound spatialisation is separated from the world of symbolic computation. We propose a model in which spatial sound rendering is regarded as a subset of sound synthesis, and spatial parameters are treated as abstract musical materials within a global compositional framework. The library OMPrisma is presented, which implements a generic system for the control of spatial sound synthesis in the computer-aided composition environment OpenMusic.

This article presents some musical and technical considerations on the handling of space in multichannel electroacoustic composition, making reference to three of my eight-channel acousmatic works: Percursos Enredados, Maresia and Sons Adentro.1 It comments on some relevant bibliography on the topic, outlining the main notions of space that informed the approach taken in the works. It also highlights how the spatial dimension of the sounds was enhanced and explored through Max/MSP patches that were used for processing the sound materials of the compositions. Finally, the article suggests some possible developments on this subject for the future.