Scan-based sound visualisation methods using sound pressure and particle velocity
Sound visualisation techniques have played a key role in the development of acoustics throughout history. Progress in measurement apparatus and the techniques used to display sound and vibration phenomena has provided excellent tools for understanding specific acoustic problems. Traditional methods, however, such as step-by-step measurements or simultaneous multichannel systems, require a significant trade-off between time requirements, flexibility, and cost. This thesis explores the foundations of a novel sound field mapping procedure. The proposed technique, Scan and Paint, is based on the acquisition of sound pressure and particle velocity by manually moving a p-u probe (pressure-particle velocity sensor) across a sound field, whilst filming the event with a camera. The sensor position is extracted by applying automatic colour tracking to each frame of the recorded video. It is then possible to directly visualise sound variations across the space in terms of sound pressure, particle velocity or acoustic intensity. The high flexibility, high resolution, and low cost characteristics of the proposed measurement methodology, along with its short time requirements, define Scan and Paint as an efficient sound visualisation technique for stationary sound fields. A wide range of specialised applications have been studied, proving that the measurement technique is not only suitable for near-field source localisation purposes but also for vibro-acoustic problems, panel noise contribution analysis, source radiation assessment, intensity vector field mapping and far field localisation.
Fernandez Comesana, D., 2014. Scan-based sound visualisation methods using sound pressure and particle velocity. PhD Thesis, University of Southampton.