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Vol 40 No 2

CONTENTS

August 2012


ARTICLES

Accounting for listening level in the prediction of reverberance using early decay time
Doheon Lee, Densil Cabrera and William L. Martens
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Estimation of noise model and denoising of wind driven ambient noise in shallow water using the LMS algorithm
S. Sakthivel Murugan,V. Natarajan and R. Rajesh Kumar
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Submarine underwater structure-borne noise and flow noise due to propeller excitation
Wei Yingsan, Yongsheng Wang, Ke Ding and Jian Fu
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TECHNICAL NOTES

Manipulation of interaural level coupled with a performer's head motion for headphone reproduction of piano sound
Sungyoung Kim, Anandhi Ramesh and William L. Martens
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Materials and musical instruments
Neville Fletcher
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The Speech Transmission Index after four decades of development
Sander van Wijngaarden, Jan Verhave and Herman Steeneken
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Wind farm noise ? an ethical dilemma for the Australian Acoustical Society?
Steven Cooper
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Effect of a 35 dB(A) minimum criterion on a wind farm development
Adam Cook, Tom Evans and Rhys Brown
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Draft national airports safeguarding framework - review of airport noise guidelines
Najah Ishac
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Protecting recreational users of firearms from impulsive noise

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Accounting for listening level in the prediction of reverberance using early decay time

Doheon Lee, Densil Cabrera and William L. Martens
Faculty of Architecture, Design and Planning, The University of Sydney, Australia This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Vol. 40, No. 2 pp 103 - 110 (2012)
ABSTRACT: Reverberance, which is an auditory attribute describing the extent to which a room or system is reverberant, is conventionally estimated using early decay time (similar to reverberation time). In a series of recent studies, the authors have shown that reverberance is better estimated using loudness decay parameters, i.e., parameters derived from the decay function of a room impulse response analysed using an objective time-varying loudness model. This approach is based on the notion that the experience of sound decaying in a room is an experience of loudness decay. One reason for the success of this approach is that the loudness decay rate depends on listening level, and this dependency corresponds to subjective experimental data on reverberance. However, loudness-based analysis is neither simple nor computationally efficient, and so this paper proposes a simplified approach to reverberance estimation, using listening level to modify early decay time or reverberation time values.

Estimation of noise model and denoising of wind driven ambient noise in shallow water using the LMS algorithm

S. Sakthivel Murugan1,V. Natarajan2 and R. Rajesh Kumar3
1Department of ECE, SSN College of Engineering, Chennai, Tamilnadu, India
2Department of Instrumentation Engineering, MIT Campus, Anna University, Chennai, India
3Infosys, Chennai, India
This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Vol. 40, No. 2 pp 111 - 121 (2012)
ABSTRACT: Signal transmission in ocean using water as a channel is a challenging process due to the effect of attenuation, spreading, reverberation, absorption etc., apart from the contribution of acoustic signals due to ambient noises. Ambient noises in sea are of two types namely manmade (shipping, aircraft over the sea, motor on boat, etc) and natural (rain, wind, marine fishes, seismic, etc). The ambient noises contribute more effect on reducing the quality of acoustic signal. In this paper we concentrate on denoising the effect due to wind on underwater acoustic signal using the LMS algorithm. The wind speed of the collected data ranges from 2.11 m/s to 6.57 m/s. The analysis is carried out for acoustic frequencies ranging from 100 Hz to 8 kHz. It is found that a linear relationship between noise spectrum and wind speed exists over the entire frequency range. The results of the empirical data are compared with the results obtained with the aid of the noise model developed. An adaptive model exploiting the Least Mean Square (LMS) algorithm to denoise wind driven ambient noise in shallow water has been proposed. The observation shows that the Signal to Noise Ratio (SNR) is enhanced two fold and the Mean Square Error (MSE) decreases exponentially with the aid of the LMS adaptive algorithm.

Submarine underwater structure-borne noise and flow noise due to propeller excitation

Yingsan Wei, Yongsheng Wang, Ke Ding and Jian Fu
Department of Mechanical Engineering, Naval University of Engineering, Wuhan, PR China This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Vol. 40, No. 2 pp 122 - 127 (2012)
ABSTRACT: TThe current study presents the numerical prediction of the noise and vibration of a small-scaled submarine under axial excitation from a 5-bladed propeller and excitation from the flow noise induced by the pulsating pressure of the hull. Firstly, the propeller flow and submarine flow were independently validated. The propulsion of the hull-propeller was simulated using computational fluid dynamics (CFD), so as to obtain the transient responses of the propeller axial excitation and the boundary pressure of the hull. Finally, the acoustic response of the submarine under axial excitation was predicted using a finite element/boundary element model in the frequency domain, and the flow noise was predicted using Curle?s analogy n the time domain.

Manipulation of interaural level coupled with a performer's head motion for headphone reproduction of piano sound

Sungyoung Kim1, Anandhi Ramesh1 and William L. Martens2
1Sound & IT Development Division, Yamaha Corporation, Hamamatsu, Japan
2Faculty of Architecture, Design and Planning, University of Sydney, NSW, Australia

Vol. 40, No. 2 pp 128 - 129 (2012)

Materials and musical instruments

Neville Fletcher
Research School of Physics and Engineering, Australian National University, Canberra

Vol. 40, No. 2 pp 130 - 133 (2012)
ABSTRACT: Many of the musical instruments with which we are familiar today have derived their basic structure from ?natural? objects, and their detail has depended upon the materials from which they can be constructed. This brief exploration of the musical instrument scene shows how this both underlies and perhaps limits their future development.

The Speech Transmission Index after four decades of development

Sander van Wijngaarden, Jan Verhave and Herman Steeneken
Embedded Acoustics BV, Delft, The Netherlands This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Vol. 40, No. 2 pp 134 - 138 (2012)
ABSTRACT: This year, the Speech Transmission Index (STI) celebrates its 40th birthday. It has been four decades since Houtgast and Steeneken first published their objective method for predicting speech intelligibility in Acustica [1]. Since then, the STI has evolved into a versatile and mature method, used in a diversity of applications. It is now more popular than ever, with record numbers of STI users as well as manufacturers of STI measuring solutions. We mark the occasion by looking back at the development of the Speech Transmission Index throughout the decades, while also presenting an overview of current developments and challenges.

Wind farm noise ? an ethical dilemma for the Australian Acoustical Society?

Steven Cooper, The Acoustic Group, Lilyfield NSW 2040 This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Vol. 40, No. 2 pp 139 - 143 (2012)
ABSTRACT: Not since the opening of the Third Runway at Sydney Airport has there been so much publicity in Australia concerning noise ? in this case wind farms. Putting aside the issue of noise versus inaudible noise there is a question being raised as to Members of the Society breaching the Code of Ethics. This is not the old question of Professional versus Learned Society. Reliance upon criteria contained in Guidelines or Standards may be an excuse by consultants that in turn places the ?fault? on the SA EPA and the New Zealand Standard. However, if people making complaints to no avail and leave their homes because of the wind farm ?noise? what is the responsibility of Members of the AAS to the community?

Effect of a 35 dB(A) minimum criterion on a wind farm development

Adam Cook1, Tom Evans2 and Rhys Brown3
1AECOM, Level 28, 91 King William Street, Adelaide, SA 5000
2 Resonate Acoustics, 97 Carrington Street, Adelaide, SA 5000
3AECOM, Level 8, 540 Wickham Street, Fortitude Valley, QLD 4006

Vol. 40, No. 2 pp 144 - 146 (2012)

Draft national airports safeguarding framework - review of airport noise guidelines

Najah Ishac, Director EMGA Mitchell McLennan Pty Ltd This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Vol. 40, No. 2 pp 147 (2012)

Protecting recreational users of firearms from impulsive noise

Vol. 40, No. 2 pp 148 - 149(2012)

 

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Click here to see draft prospectus. Suggestions for major activities that would be truly international to strengthen the application are welcomed.

 

ACOUSTICS 2017

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