Sound radiation characteristics of a box-type structure

The finite element and boundary element methods are employed in this study to investigate the sound radiation characteristics of a box-type structure. It has been shown [T.R. Lin, J. Pan, Vibration characteristics of a box-type structure, Journal of Vibration and Acoustics, Transactions of ASME 131 (2009) 031004-1–031004-9] that modes of natural vibration of a box-type structure can be classified into six groups according to the symmetry properties of the three panel pairs forming the box. In this paper, we demonstrate that such properties also reveal information about sound radiation effectiveness of each group of modes. The changes of radiation efficiencies and directivity patterns with the wavenumber ratio (the ratio between the acoustic and the plate bending wavenumbers) are examined for typical modes from each group. Similar characteristics of modal radiation efficiencies between a box structure and a corresponding simply supported panel are observed. The change of sound radiation patterns as a function of the wavenumber ratio is also illustrated. It is found that the sound radiation directivity of each box mode can be correlated to that of elementary sound sources (monopole, dipole, etc.) at frequencies well below the critical frequency of the plates of the box. The sound radiation pattern on the box surface also closely related to the vibration amplitude distribution of the box structure at frequencies above the critical frequency. In the medium frequency range, the radiated sound field is dominated by the edge vibration pattern of the box. The radiation efficiency of all box modes reaches a peak at frequencies above the critical frequency, and gradually approaches unity at higher frequencies.

Beyond the sound barrier

Freeway barriers used to be just great slabs of concrete that lined the road to tr and protect nearby residents from the constant rumble of the traffic. But in recent years, their visual appeal has become as important as their practical purpose with architects and designers clamouring to show off their ideas to the vast traveling public. Melbourne's Craigieburn Bypass is the latest to be recognised for its dual appeal winning the Urban Design Award at the recent Victorian Architecture Awards.

Aural auteur : sound in the films of Rolf de Heer

An interpretative methodology for understanding meaning in cinema since the 1950s, auteur analysis is an approach to film studies in which an individual, usually the director, is studied as the author of her or his films. The principal argument of this thesis is that proponents of auteurism have privileged examination of the visual components in a film-maker’s body of work, neglecting the potentially significant role played by sound. The thesis seeks to address this problematic imbalance by interrogating the creative use of sound in the films written and directed by Rolf de Heer, asking the question, “Does his use of sound make Rolf de Heer an aural auteur?” In so far as the term ‘aural’ encompasses everything in the film that is heard by the audience, the analysis seeks to discover if de Heer has, as Peter Wollen suggests of the auteur and her or his directing of the visual components (1968, 1972 and 1998), unconsciously left a detectable aural signature on his films. The thesis delivers an innovative outcome by demonstrating that auteur analysis that goes beyond the mise-en-scène (i.e. visuals) is productive and worthwhile as an interpretive response to film. De Heer’s use of the aural point of view and binaural sound recording, his interest in providing a ‘voice’ for marginalised people, his self-penned song lyrics, his close and early collaboration with composer Graham Tardif and sound designer Jim Currie, his ‘hands-on’ approach to sound recording and sound editing and his predilection for making films about sound are all shown to be examples of de Heer’s aural auteurism. As well as the three published (or accepted for publication) interviews with de Heer, Tardif and Currie, the dissertation consists of seven papers refereed and published (or accepted for publication) in journals and international conference proceedings, a literature review and a unifying essay. The papers presented are close textual analyses of de Heer’s films which, when considered as a whole, support the thesis’ overall argument and serve as a comprehensive auteur analysis, the first such sustained study of his work, and the first with an emphasis on the aural.

Predictions of angle dependent tortuosity and elasticity effects on sound propagation in cancellous bone

The anisotropic pore structure and elasticity of cancellous bone cause wave speeds and attenuation in cancellous bone to vary with angle. Previously published predictions of the variation in wave speed with angle are reviewed. Predictions that allow tortuosity to be angle dependent but assume isotropic elasticity compare well with available data on wave speeds at large angles but less well for small angles near the normal to the trabeculae. Claims for predictions that only include angle-dependence in elasticity are found to be misleading. Audio-frequency data obtained at audio-frequencies in air-filled bone replicas are used to derive an empirical expression for the angle-and porosity-dependence of tortuosity. Predictions that allow for either angle dependent tortuosity or angle dependent elasticity or both are compared with existing data for all angles and porosities.

Soundcipher : a music and sound library for processing

SoundCipher is a software library written in the Java language that adds important music and sound features to the Processing environment that is widely used by media artists and otherwise has an orientation toward computational graphics. This article introduces the SoundCipher library and its features, describes its influences and design intentions, and positions it within the field of computer music programming tools. SoundCipher enables the rich history of algorithmic music techniques to be accessible within one of today’s most popular media art platforms. It also provides an accessible means for learning to create algorithmic music and sound programs.

Sound in the Aboriginal Australian Films of Rolf de Heer

Anna Hickey-Mody and Melissa Iocca invented a new name for the cinema-goer at "Bad Boy Bubby" (1993) when they wrote: "In de Heer's film, the viewer is primarily a listener, or aurator, and secondly a spectator" and I have argued the label 'aurator' can also be used for the person experiencing "Ten Canoes" (2006). This Aboriginal Australian Dreamtime fable features dialogue recorded entirely in the Ganalbingu language of the Indigenous people it stars, and is a prime example of what I would suggest can be labeled 'The Aboriginal Australian Films of Rolf de Heer'. "The Tracker" (2002) and "Dr. Plonk" (2007) have also included depictions of Aboriginal Australians and each of the trio utilizes Cat Hope's "innovative sound ideas" to present what I argue is an aural auteur's signature revealing a post-colonial Australian world-view that privileges the justice system and eco-spirituality of Aboriginal Australians.

An interview with sound artist Guy Webster by Jillian Hamilton and Jeremy Yuille

Guy Webster is a sound artist who has been featured in numerous festivals, galleries, conferences and theatres in Australia, Japan, UK and Europe. As part of the Transmute Collective he developed the immersive soundscape of Intimate Transactions. On 2nd November, 2005 Jilliann Hamilton and Jeremy Yuille met with Guy Webster to discuss his approach to immersion in soundsapes.

YouTube versus the national film and sound archive: Which is the more useful resource for historians of Australian television?

This article compares YouTube and the National Film and Sound Archive (NFSA) as resources for television historians interested in viewing old Australian television programs. The author searched for seventeen important television programs, identified in a previous research project, to compare what was available in the two archives and how easy it was to find. The analysis focused on differences in curatorial practices of accessioning and cataloguing. NFSA is stronger in current affairs and older programs, while YouTube is stronger in game shows and lifestyle programs. YouTube is stronger than the NFSA on “human interest” material—births, marriages, and deaths. YouTube accessioning more strongly accords with popular histories of Australian television. Both NFSA and YouTube offer complete episodes of programs, while YouTube also offers many short clips of “moments.” YouTube has more surprising pieces of rare ephemera. YouTube cataloguing is more reliable than that of the NFSA, with fewer broken links. The YouTube metadata can be searched more intuitively. The NFSA generally provides more useful reference information about production and broadcast dates.

Continuous and pedagogically sound assessment : A new economy of power relations in Australian Law schools

In recent decades, assessment practices within Australian law schools have moved from the overwhelming use of end-of-year closed-book examinations to an increase in the use of a wider range of techniques. This shift is often characterised as providing a ‘better’ learning environment for students, contributing more positively to their own ‘personal development’ within higher education, or, considered along the lines of critical legal thought, as ‘liberating’ them from the ‘conservatising’ and ‘indoctrinating’ effects of the power relations that operate in law schools. This paper seeks to render problematic such liberal-progressive narratives about these changes to law school assessment practices. It will do so by utilising the work of French historian and philosopher Michel Foucault on power, arguing that the current range of assessment techniques demonstrates a shift in the ‘economy’ of power relations within the law school. Rather than ‘liberating’ students from relations of power, these practices actually extend the power relations through which students are governed. This analysis is intended to inform legal education research and assessment practice by providing a far more nuanced conceptual framework than one that seeks to ‘free’ law students from these ‘repressive’ practices, or hopes to ‘objectively’ contribute to their ‘personal development’.

Characteristics of modal sound radiation of finite cylindrical shells

Characteristics of modal sound radiation of finite cylindrical shells are studied using finite element and boundary element methods in this paper. In the low frequency range, modal radiation efficiencies of finite cylindrical shells are found to asymptotically approach those of the corresponding infinite cylindrical shell when structural trace wavelengths of the cylindrical shells are greater than the acoustic wavelength. Modal radiation efficiencies for each group of modes having the same circumferential modal index decrease as the axial modal index increases. They converge to each other when the axial trace wavelength is much greater than the circumferential trace wavelength. The mechanism leading to lower radiation efficiency of modes with higher circumferential modal index of short cylinders is explained. Similar to those of flat plate panels, change in slope or waviness is observed in modal radiation efficiency curves of modes with higher order axial modal index at medium frequencies. This is attributed to the interference of sound radiated by neighbouring vibrating cells when the distance between nodal lines of a vibrating mode is in the same order or smaller than the acoustic wavelength. Effects of the internal sound field on modal radiation efficiencies of a finite open-end cylinder are discussed.

Sound thinking : tips and tools for understanding popular music

Sound Thinking provides techniques and approaches to critically listen, think, talk and write about music you hear or make. It provides tips on making music and it encourages regular and deep thinking about music activities, which helps build a musical dialog that leads to deeper understanding.

Physically sound vehicle-driver model for realistic microscopic simulation

In microscopic traffic simulators, the interaction between vehicles is considered. The dynamics of the system then becomes an emergent property of the interaction between its components. Such interactions include lane-changing, car-following behaviours and intersection management. Although, in some cases, such simulators produce realistic prediction, they do not allow for an important aspect of the dynamics, that is, the driver-vehicle interaction. This paper introduces a physically sound vehicle-driver model for realistic microscopic simulation. By building a nanoscopic traffic simulation model that uses steering angle and throttle position as parameters, the model aims to overcome unrealistic acceleration and deceleration values, as found in various microscopic simulation tools. A physics engine calculates the driving force of the vehicle, and the preliminary results presented here, show that, through a realistic driver-vehicle-environment simulator, it becomes possible to model realistic driver and vehicle behaviours in a traffic simulation.