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Vol 31 No 3

CONTENTS

December 2003


ARTICLES

Differential Sensitivity of the Ear for Underwater Pure Tones
K Kuramoto, S Kuwahara, K Oimatsu, S Yamaguchi
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The Microflown: An Acoustic Particle Velocity Sensor
H-E de Bree
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Vocal Tract Resonances: A Preliminary Study of Sex Differences for Young Australians
T Donaldson, D Wang, J Smith & J Wolfe
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Railway Bonus for Sounds Without Meaning?
H Fastl, M. Fruhmann & S. Ache
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The Statistical Estimation of the Attenuation of Impulse Peak Levels with Respect to Distance
W Williams
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ACOUSTICS FORUM:

Science Meets Parliament
M Burgess & J Wolfe
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Australian Acoustical Society Membership Survey>
D Watkins & M Burgess
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Obituary
News
New Members
Future Meetings
Meeting Reports
New Products
Book Reviews
Diary
Acoustics Australia Information
Australian Acoustical Society Information
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DIFFERENTIAL SENSITIVITY OF THE EAR FOR UNDERWATER PURE TONES

Kazuoki Kuramoto,1 Shin?ya Kuwahara,1 Kensei Oimatsu,1 Shizuma Yamaguchi2
1Japan Coast Guard Academy, 5-1 Wakaba, Kure 737-8512
2Faculty of Engineering,Yamaguchi University, 2557 Tokiwadai, Ube 755-8611
JAPAN

Vol. 31, No. 3 pp 87 - 90 (2003)
ABSTRACT: As a part of the research for constructing an underwater transmission system to divers, differential sensitivity of the ear in water to sound intensity and frequency was examined by listening experiments in a water tank. Although the value of minimum audible field (MAF) in water was considerably different from that in air, it is found that the dependence of differential sensitivity at the same sensation level (SL) is almost the same both in water and in air. Resolution of the auditory sense (i.e. number of steps in distinguishable sound) was estimated in the underwater auditory area by using existing results in air.

THE MICROFLOWN:AN ACOUSTIC PARTICLE VELOCITY SENSOR

Hans-Elias de Bree
Microflown Technologies Einsteinstraat 7, 6900 AH Zevenaar
NETHERLANDS This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Vol. 31, No. 3 pp 91 - 94 (2003)
ABSTRACT: The Microflown is an acoustic sensor directly measuring particle velocity instead of sound pressure, which is usually measured by conventional microphones. Since its invention in 1994 it is mostly used for measurement purposes (broadband 1D and 3Dsound intensity measurement and acoustic impedance). Possible applications are near and far field sound source localization, in-situ acoustic impedance determination and a non-contact method to measure structural vibrations (an alternative for a laser vibrometer). The Microflown, invented only a few years ago, is now commercially available.

VOCAL TRACT RESONANCES: A PRELIMINARY STUDY OF SEX DIFFERENCES FOR YOUNG AUSTRALIANS

Tina Donaldson, Diana Wang, John Smith and Joe Wolfe
School of Physics, University of New South Wales, Sydney 2052

Vol. 31, No. 3 pp 95 - 98 (2003)
ABSTRACT: We report direct measurements of the first two resonance frequencies of the vocal tracts of young women university students producing the vowels of Australian English. The resonances are determined from the response of the tract to a broad band, external, acoustic source. From these data we construct a vowel resonance map for these Australian women and compare it with the corresponding data for a sample of young Australian men, also university students.

RAILWAY BONUS FOR SOUNDS WITHOUT MEANING?*

Hugo Fastl, Markus Fruhmann, Simon Ache
AG Technische Akustik, MMK, TU-Muenchen
Arcisstr. 21, D-80333 Muenchen, Germany
*Originally presented at WESPAC8, Melbourne, April 2003

Vol. 31, No. 3 pp 99 - 101 (2003)
ABSTRACT: At same A-weighted energy-equivalent level, railway noise frequently is preferred to road traffic noise. This effect often is called railway bonus. Among possible reasons for the railway bonus, differences in spectrum, time structure, and meaning of sound are discussed. In order to largely "neutralize" the meaning of sound, a procedure was proposed as follows: the sound, e.g. railway noise, is analyzed by Fourier-Time-Transform (FTT) and - after spectral broadening - re-synthesized by inverse FTT. The procedure has the advantage that the loudness-time functions of original and neutralized sound are identical, but the meaning of the sound is removed. In psychoacoustics experiments, for original sounds of railway versus road traffic noise, a railway bonus could be ascertained. If for the same sounds, when deprived from their meaning, also a railway bonus would show up, then the meaning of sound would contribute to the railway bonus much less than differences in spectrum and/or time structure. If, on the other hand, the meaning of sound would be a dominant factor for the railway bonus, with neutralized sounds no railway bonus should show up. Results of corresponding psychoacoustics experiments are reported and discussed in view of the psychophysical method used.

THE STATISTICAL ESTIMATION OF THE ATTENUATION OF IMPULSE PEAK LEVELS WITH RESPECT TO DISTANCE

Warwick Williams
National Acoustic Laboratories, 136 Greville St, Chatswood, NSW

Vol. 31, No. 3 pp 103 - 107 (2003)
ABSTRACT: This paper presents a summary of experimental work carried out on impulsive noise propagation over distances up to 3.2 kilometers. The average attenuation of the maximum peak level (MAXP) is examined with respect to distance for all times of day and widely varying geographical and meteorological conditions. Formulae for predicting impulse attenuation are derived from the data using both spherical spreading and a curve of best-fit method. Possibly more important is the fact that the MAXP levels measured at any one location can lie over a wide range for example, up to 50 dB at 3.2 km. This has important implications for the prediction of annoyance and indicates that more consideration should be given to the statistical spread of results derived from experimental work.

 

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