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Vol 27 No 2

CONTENTS

August 1999


ARTICLES

Characterisation of Soft Impact Damage In Composite Sandwich Panels Using a "Pitch-Catch" Acoustic Probe
Laurence P. Dickinson & Suszanne Thwaltes
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The Perception of Pitch by Users of Cochlear Implants: Possible Significance for Rate and Place Theories of Pitch
Robert Fearn, Paul Carter and Joe Wolfe
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Quiet Please it's a Hospital
K. Mikl & K. Mathiasch
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Sonar Systems for Sea Bed Imaging
Bryan WoodWard
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Noise Effects 98 - A Summary: 7th International Congress on Noise as a Public Health Problem, 22-26 November 1998, Sydney Australia
Jerry V. Tobias
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RESEARCH NOTE

Vibrato Frequency and Phase Lock in Operatic Duet Quality
Melanie Duncan, Carol Williams, Gordon Troup
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The Australian Acoustical Society in the 21st C here to Now? Time to reconsider?
Graeme Yates
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Characterisation of Soft Impact Damage In Composite Sandwich Panels Using a "Pitch-Catch" Acoustic Probe

Laurence. P. Dickinson & Suszanne Thwaites
CSlRO Telecommunications and Industrial Physics
Sydney NSW 2070

Vol. 27, No. 2 pp 37-41 (1999)
ABSTRACT: This paper diocusses an investigation of the detection of low-velocily, soft impact damage in Nomex honeycomb cored, carbon fribe composite sandwich. panels using a low frequency acoustic technique. A commerically available probe head was used on an automated scanning table to perform a raster scan on prepred test panels. Various processing techmques were used to analyse the data but it was found that a simple integrated difference algorithm provided a surprising amount of detail about core damage that is virtiually invisible on the panel surface. The patterns emerged form scans appear mode-like and the complexity looks tpo be related to impact severity.

The Perception of Pitch by Users of Cochlear Implants: Possible Significance for Rate and Place Theories of Pitch

Robert Fearn*, Paul Carter' and Joe Wolfe*
*School of Physics, The University of New South Wales, Sydney 2052 Australia
'Cochlear Ltd, Lane Cove, 2066 Australia

Vol. 27, No. 2 pp 41-43 (1999)
ABSTRACT: This study used subjects who had lost their hearing after acquiring language and who used cochlear implants. Trains of electrical pulses with different rates were sent to electrodes in different positions along the cochlea. Subjects report peceived pitch using and arbitrary scale which was later normalised among subjects. Perceived pitch increased approximately logarithmically with rate, but decreased with the distance of the stimulation area from the cochlear windows. At high rates of stimulation, peceived pitch also decreased with distance from the windows but had little dependence on stimulation rate.

Quiet Please it's a Hospital

K. Mikl & K. Mathiasch
WorkCover NSW
919 Londonderry Rd
Londonderry NSW 2753

Vol. 27, No. 2 pp 45-46 (1999)
ABSTRACT: Traditionally one would expect a hospital to be a quiet place in which to work wilh no risk of noise induced hearing loss. This study examines common noise sources in 32 hospitals around NSW. The noise sources are grouped according to function and section to determine average noise levels, their range and standard deviation. Due to the newly introduced measure for peak noise, peak noise levels were also measured, even though the 140dB peak limit was not expected to exceeded. Results show that a hospital is not necessarily quiet and that a significant number of noisey jobs exist, particularly in the carpentry, engineering and gardening sections.

Sonar Systems for Sea Bed Imaging

Bryan Woodward FIOA
Professor of Underwater Acoustics
Department of Electronic and Electrical Engineering
Loughborough University, UK

Vol. 27, No. 2 pp 47-52 (1999)
ABSTRACT: A review of the operation and capabilities various undersea sonar systems, including synthetic aperture sonar, the seismic profiler, and parametric sonar.

Noise Effects 98 - A Summary: 7th International Congress on Noise as a Public Health Problem, 22-26 November 1998, Sydney Australia

Jerry V. Tobias
Tobias Consulting,
Box 1609, Groton, CT 06340-1609, USA

 

Newsflash

PROPOSED INTERNATIONAL YEAR OF SOUND 2019

Let's make 2019 the International Year of Sound!

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

 

ACOUSTICS 2017

Perth, Western Australia 19-22 November 2017