Spatial audio engineering: exploring height in acoustic space

Techniques for recording and reproducing an authentic immersive 3D audio experience are evolving rapidly as new technologies and new delivery platforms emerge for sound art installations, museum and gallery exhibits, and immersive cinema formats. A creative practitioner in this field requires a broad range of skills: spatial composition, creating unique sounds specifically intended for use in a spatial sound work; spatial sound design, using existing sounds and manipulating them into 3D acoustic space; and spatial recording, capturing the location and movement of sounds in space and the sonic identity of acoustic spaces. This practice-led research explored the continuum of skills, knowledge and experience between the art, craft and science of audio engineering and the creative practice of a spatial composer and spatial sound designer. As a lifelong, passionate listener and professional audio engineer, the integration of psycho-acoustic theories about spatial hearing into my focussed listening formed the foundation of my transition into spatial audio engineering, expanding my knowledge and skills from stereo and horizontal-only surround to full 3D reproduction through the exploration of height in acoustic space. This research examined these complex issues of aural perception in terms of spatialization techniques, spatial sound design and spatial compositional approaches to the use of 3D space as an aesthetic parameter. An affordable project studio for a 3D listening environment is presented as a consistent reference for reproducing an authentic immersive 3D audio experience. The practice-led research program developed innovative techniques for spatial recording and established a repertoire of electronic and acoustic techniques for spatializing existing recordings into 3D acoustic space. A series of spatial sound works are presented and analysed for the perceptual effectiveness of their spatialization techniques, with particular attention paid to the role of height in aural perception. The research has been listener focussed, with no front bias in sound works and no intention of linking sounds to a visual image or creating a virtual stage or screen. This thesis outlines the development of a spatial audio creative practice from the perspective of an audio engineer, in the light of published research and interviews with practitioners, examining creative workflows and linking spatialization techniques to their perceptual effects through thousands of hours of focussed listening. The sound works produced translate effectively from the studio to a listener in a reproduced 3D aural environment