Contents of issue 4, vol. 29 (2004)

  1. M. Kordus, A. Sęk, Monaural and binaural detection thresholds of amplitude modulation, Archives of Acoustics, 29, 4, 537-553
  2. S. Brachmański, Estimation of logatom intelligibility with the STI method for Polish speech transmitted via communication channels, Archives of Acoustics, 29, 4, 555-562
  3. L. Stryczniewicz, Identification of zones of increased vibroacoustic emission by means of the inverse method, Archives of Acoustics, 29, 4, 563-576
  4. Y.-C. Chang, L.-J. Yeh, M.-C. Chiu, GA optimization on single-chamber muffler hybridized with extended tube under space constraints, Archives of Acoustics, 29, 4, 577-596
  5. T. Powałowski, Z. Trawiński, Non-invasive ultrasonic examination of the local pulse wave velocity in the common carotid artery, Archives of Acoustics, 29, 4, 597-606
  6. J. Wójcik, Nonlinear reflection and transmission of plane acoustic waves, Archives of Acoustics, 29, 4, 607-632
  7. S. Kowalski, M. Sikorski, Ultrasonic waves in densified suspensions, Archives of Acoustics, 29, 4, 633-646
  8. A. Perelomova, Acoustic streaming caused by modulated sound and wave packets, Archives of Acoustics, 29, 4, 647-654
  9. Chronicle, Report of the XXIth Symposium on Hydroacoustics, Archives of Acoustics, 29, 4, 655-666
  10. Chronicle, Prof. Jerzy Sadowski - 80th birthday, Archives of Acoustics, 29, 4, 667-668
  11. Chronicle, Prof. Stefan Ernst - 70th birthday, Archives of Acoustics, 29, 4, 669-670
M. Kordus, A. Sęk, Monaural and binaural detection thresholds of amplitude modulation
Adam Mickiewicz University, Institute of Acoustics
Umultowska 85, 61-614 Poznań, Poland
email: mkordus@amu.edu.pl
(received 19 September 2003; accepted 23 September 2004)
This study is concerned with the amplitude modulation (AM) detection thresholds for monaural and binaural listening. In the first experiment, using a Two-Alternative Forced-Choice (2AFC) method with an adaptive procedure 2-up 1-down, the monaural and binaural AM detection thresholds were measured. Sinusoidal carrier at a frequency of 160, 500, 1000 or 4000 Hz was amplitude-modulated by a single sinusoidal modulator at a frequency of 4, 32, 64 or 128 Hz.
Due to a significant intersubject scatter of the results it was impossible to estimate the difference between the thresholds determined for monaural and binaural presentation of the stimuli. Therefore, in the next experiment, psychometric functions for AM detection for both monaural and binaural listening were determined. This experiment was carried out for sinusoidal carriers at frequencies of 5000, 2000 and 6000 Hz and for sinusoidal modulator at frequencies of 4, 64 and 128 Hz. The results of this experiment showed a statistically significant difference between slopes of the psychometric function (after the percent of correct responses was converted to the detectability, d', domain) for monaural and binaural stimuli presentation. Assuming that the AM threshold coincided with d' = 1 it can be stated that monaural and binaural AM thresholds are significantly different.
Key words: binaural and monaural thresholds, auditory filters, amplitude modulation, modulation filter bank.


S. Brachmański, Estimation of logatom intelligibility with the STI method for Polish speech transmitted via communication channels
Wrocław University of Technology, Institute of Telecommunications and Acoustics
Wybrzeże Wyspiańskiego 24, 50-370 Wrocław, Poland
email: stefan.brachmanski@pwr.wroc.pl
(received 23 February 2004; accepted 23 September 2004)
An objective measure of the quality of speech communication channels was introduced and described by Steeneken-Houtgast. By calculating the Speech Transmission Index (STI), this method provides an estimate of logatom intelligibility for a variety of communication distortions. Using the logatom test for speech intelligibility, it was shown that the STI method is a valid method for the assessment of the quality of the speech transmitted over communications channels intended for use with the Polish language. New STI curves were generated for the Polish speech intelligibility.
Key words: speech quality, speech intelligibility, logatom intelligibility, speech transmission index, STI.


L. Stryczniewicz, Identification of zones of increased vibroacoustic emission by means of the inverse method
AGH University of Science and Technology
Mickiewicza 30, 30-059 Kraków, Poland
e-mail: stryczni@agh.edu.pl
(received 29 September 2003; accepted 21 May 2004)
The basic formulas concerning the inversion are presented in the paper. Examples of the author's studies on the possibility of the localization of zones of increased vibroactivity by means of the inverse method are given. The inverse method is very sensitive to the position of substitute sources. This feature can be used for the determination of the position of actual sources. The accuracy of the method depends also on the distribution of the observation points. The dependence of the position of substitute sources on their acoustic power level is discussed in the paper as well.
The distribution of the acoustic fields around the air compressor is given as an example. The~measurements were performed at the points distributed on a semi-sphere. Both the amplitude and phase of the acoustic pressure were determined at each measuring point. On the basis of the results obtained, the zones of increased acoustic emission were searched for.
Key words: acoustic modeling, inverse method, sound source.


Y.-C. Chang, L.-J. Yeh, M.-C. Chiu, GA optimization on single-chamber muffler hybridized with extended tube under space constraints
Tatung University, Department of Mechanical Engineering
Taipei, Taiwan 104, R.O.C.
email: min-chie.chiu@etci.com.tw, ljyeh@ttu.edu.tv, cchang@ttu.edu.tw
(received 27 November 2003; accepted 23 September 2004)
Mufflers are habitually adopted in gas venting systems under space constraint for maintenance and operation. The shape optimization in the muffler to maximize the sound performance is then highly focused, accordingly.
In this paper, the shape design of a muffler with extended tubes optimized by the genetic algorithm (GA) is presented. A numerical case in eliminating the pure tone noise is introduced. Before optimization, the mathematical model is compared by the experimental data for an accuracy check. The results indicate that the sound transmission loss (STL) is maximized exactly at the designed frequency. Consequently, we demonstrate a successful GA application on the muffler design.
Key words: single-chamber muffler hybridized with extended tube, transfer matrix method, space constraints, GA optimization.


T. Powałowski, Z. Trawiński, Non-invasive ultrasonic examination of the local pulse wave velocity in the common carotid artery
Institute of Fundamental Technological Research, Polish Academy of Sciences
Ultrasonic Department
Świętokrzyska 21, 00-049 Warszawa, Poland
email: tpowal@ippt.gov.pl
(received 23 September 2004; accepted 18 October 2004)
Local pulse wave velocity (PWV) is one of important indicators of artery wall's elastic properties. This paper describes a non-invasive method of examinations of local PWV on the basis of ultrasonic blood flow velocity measurements at two points, several centimetres along the common carotid artery (CCA). This velocity was compared with values of PWV calculated on the basis of measurement of distensibility coefficient DC. The examinations were carried out on the group of 12 healthy volunteers ranging in age from 22 to 68 years (mean 39±16 years). Mean value of local PWV for the examined group was 5.1±1.09 m/s. This velocity was linearly correlated (r = 0.9807) with the PWV examined on the basis of distensibility coefficient DC, the mean value of which was 6.14±1.29 m/s.
Key words: local pulse wave velocity, common carotid artery, ultrasound.


J. Wójcik, Nonlinear reflection and transmission of plane acoustic waves
Institute of Fundamental Technological Research, Polish Academy of Sciences
Department of Ultrasound
Świętokrzyska 21, 00-049 Warszawa, Poland
e-mail: jwojcik@ippt.gov.pl
(received 4 November 2003; accepted 21 May 2004)
In the present, paper the classical problem of reflection and transmission of a plane acoustic wave is analyzed and solved for nonlinear propagation. Two adjacent media with a plane boundary between them are assumed. The parameters characterizing the properties of the media can be changed stepwise on the boundary. The wave incident on the boundary surface is plane. It was assumed that the disturbance in the first medium is a superposition of the incident and reflected waves, and in the second medium there is only the transmitted wave. On the base of nonlinear acoustic equations, assuming continuity of the velocity and pressure fields, the reflection and transmission operators of velocities and pressures were determined. The operators are nonlinear in relation to the incident wave field. It was found that near the boundary there occurs "a reflecting-transmitting" layer which is decisive for the description of the nonlinear phenomenon of the reflection and transmission. There arises a nonlinear feedback between the reflecting and incident waves. This is the fundamental difference between the nonlinear and the linear reflection. Equations of the incident reflected and transmitted waves are given. In the case of classical viscous media, they are the Burger's equations in asymptotic areas. The operators and the experimental significance of the results obtained were additionally discussed. An example of the effective application of the analysis performed is given in Sec. 6.
Key words: reflection, transmission, nonlinearity.


S. Kowalski, M. Sikorski, Ultrasonic waves in densified suspensions
Poznań University of Technology
Institute of Technology and Chemical Engineering
pl. Marii Skłodowskiej Curie 2, 60-965 Poznań, Poland
email: kowal@rose.man.poznan.pl
(received 22 November 2003; accepted 21 May 2004)
A theory of propagation of ultrasonic waves in sediments is developed. The formulae for the phase velocity and the attenuation coefficient are determined as functions of wave frequency and the mass fraction of the solid phase. These formulae can be used, after suitable calibration, for determination of the solid mass fraction or the water content in densified suspensions. These structure parameters can be determined by measuring the transition time of ultrasonic wave through a given distance of sediment. The phase velocity dispersion curves and the attenuation coefficients determined theoretically and experimentally are plotted as functions of the solid mass fraction for sediment.
Key words: ultrasounds, sediment, wave propagation, phase velocity, attenuation coefficient.


A. Perelomova, Acoustic streaming caused by modulated sound and wave packets
Gdańsk University of Technology
Narutowicza 11/12, 80-952 Gdańsk, Poland
email: anpe@mifgate.pg.gda.pl
(received 20 December 2003; accepted 23 September 2004)
The practical applications of sound relate to approximately periodic sounds. It is shown, that theoretical results of acoustic streaming based on a periodic everywhere sound, should be revised in spite of the experimental data demonstrating the essentially different velocities of streaming. A new approach, which allows evaluating the streaming caused by sound of every type, both periodic and non-periodic, leads to similar results. The results of numerical calculations of streaming caused by modulated sound and series of pulses are compared with those given by formulae for a periodic everywhere sound.
Key words: acoustic streaming, non-periodic sound, wavepackets.


Chronicle, Report of the XXth Symposium on Hydroacoustics
Gdańsk - Jurata, May 25-28, 2004, Poland
Symposium on Hydroacoustics The Scientific and Organising Committee of the XXIst Symposium on Hydroacoustics have the pleasure to present the abstracts of papers submitted at this event.
The Symposium programme included invited lectures and contributed papers covering main research fields of hydroacoustics. All contributed papers submitted to the Scientific Committee were reviewed and classified into eight sessions covering the following areas of hydroacoustics:
  • Acoustics in Fisheries,
  • Instrumentation and Measurements,
  • Nonlinear Acoustics,
  • Sea Floor Characterisation,
  • Signal and Data Processing,
  • Sonar Systems,
  • Sound Propagation in the Sea,
  • Transducers and Antennas.
  • Invited key-note speakers presented the following papers:
    1. I. Gloza, Underwater ship passport;
    2. J. Ilczuk, J. Bluszcz, R. Zachariasz, Stability of mechanical and dielectric parameters in PZT based ceramics;
    3. A. Nowicki, I. Trots, W. Secomski, J. Litniewski, Golay's codes sequences in ultrasonography;
    4. A. Orłowski, Acoustic reconnaissance of fish and evironmental background in demersal zone in Southern Baltic;
    5. R. Salamon, Directional sonobuoy system for detection of submarines.
    The accepted papers will be published in the Annual Journal "HYDROACOUSTICS".
    Eugeniusz Kozaczka - Chairman of the Scientific Committee.
    Ignacy Gloza - Chairman of the Organising Committee.


    Professor Jerzy Sadowski - 80-th birthday
    Professor Jerzy Sadowski Professor Jerzy Sadowski, Ph.D., D.Sc., was born on the Dec. 18-th, 1924 in Augustów. Married, has three children.
    In 1952 he graduated from the Technical University of Warsaw, where he took his M.Sc. degree at the Faculty of Communication.
    He started his professional career as an acoustics designer, dealing with room acoustics and noise protection of different industrial buildings. In 1958 he began his work in Building Research Institute (ITB), where he soon organised Department of Acoustics. He directed this department uninterruptedly until 2003, creating a leading research center in Poland dealing with acoustics in construction and environment.
    Professor Jerzy Sadowski quickly attained several scientific degrees and titles. In 1962 he took his doctor's degree in technical sciences at the Technical University of Silesia. In 1970 he was appointed associate professor at the Technical University of Warsaw, and then in 1973 he became professor and full professor in 1980.
    The scientific accomplishments of Professor Sadowski are mainly connected with the Building Research Institute and the Department of Acoustics directed by him, the research profile of which he personally shaped. The main areas of his research and his activity as an expert, concern room acoustics (with emphasis on special-use premises), building, installation, urban, environmental acoustics, acoustics surveying, and standardisation issues. Professor Sadowski deals with the evaluation of acoustic performance of construction and installation products, problems of noise propagation in building structures and shaping the acoustics climate in buildings, with special emphasis placed on residential buildings. He conducted large-scale research on the subjective evaluation of the acoustic conditions in buildings and the influence of these conditions on residents' health. Professor Sadowski is the author of the first noise maps in Poland and the author of methodology of determining the degree of noise hazard in cities and urban areas.
    Published attainments of Professor Sadowski encompass over 20 monographs published by Arkady, PWN etc., over 240 articles in Polish and foreign scientific and technical magazines and over 30 papers presented at conferences in Poland and abroad. He is the author or co-author of about 10 reports on the noise hazard, programmes on noise abatement, the expert adviser of legal acts, the author or co-author of proposals addressed to state administration bodies pointing out the incorrect situations occurring in Poland in the area of noise protection and the need to undertake immediate remedial actions. A significant part of the research work of Professor J. Sadowski is his activity as a co-ordinator in many governmental programmes on noise protection in the construction industry and environment.
    Professor Sadowski promoted 13 doctors in the technical sciences, the area of construction, with specialisation in building acoustics. He was the reviewer of many other doctoral theses and postdoctoral dissertations as well as proposals for professor's title.
    Professor Sadowski has also vast achievements in his engineering work in the Broadcasting and Television Design Office in Warsaw in 1959-1964. He is the author of designs and implementation of radio and television studios, film studios, conference, theatre and cinema halls and many other buildings requiring special conditions in terms of noise protection and room acoustics.
    Professor Sadowski took part in many works of foreign technical organisations, e.g. CIB W-51, ISO TC43 and also Polish scientific and technical organisations connected with noise and vibration protection, as well as in the Scientific Boards of many Research Institutes (also in Scientific Board of the Building Research Institute - ITB).
    For his research and publications he received 23 awards from the Ministers of the Building Industry and of Environment (part of these awards were granted individually, part - in a team).
    Professor Jerzy Sadowski was awarded many high-ranking state decorations and received many other distinctions from different scientific and technical organisations. Barbara Szudrowicz


    Professor Stefan Ernst 70-th birthday
    Professor Stefan Ernst Stefan Ernst was born in Piaśniki, Upper Silesia, in 1934. He studied chemistry at the University of Wrocław, where he received his M.Sc. degree and Ph.D degree in 1959 and 1967, respectively. Prof. B. Jeżowska-Trzebiatowska, to whom he always refers with high esteem, supervised his thesis "Association-Dissociation Equlibria and the Structure of Uranyl Compounds in Organic Solvents".
    The way from junior scientist to expert, Professor Ernst went at the University of Wrocław with breaks for stays at other universities. In the years 1970/71, he received a research grant from the University of Kansas, U.S.A. Next academic year he was a visiting lecturer at the University of Salford, U.K. In 1980 he completed his D.Sc. degree in Wrocław and moved to the University of Silesia in Katowice. He is active there until today. As a professor of the University, he was appointed the head of the Department of Physical Chemistry at the Institute of Chemistry, Faculty of Mathematics, Physics and Chemistry in 1980. He has been the Deputy Director at the Institute of Chemistry for many years.
    In his Department, Professor Ernst organised very efficiently laboratories of ultrasound and molecular acoustics. Since very beginning, his research interests have been focused on application of molecular acoustics in investigations of single- and multicomponent liquid phases. It is worth to add that this research interests of Professor Ernst was started already in Wrocław where at early years 70-th of XX century, ultrasonic investigations of liquid phases at the University were initiated by Prof. Jeżowska-Trzebiatowska.
    Professor Ernst is author and co-author of several dozen scientific publications in Polish and foreign journals: Acustica, Archives of Acoustics, Fluid Phase Equlibria, Journal of Chemical and Engineering Data, Molecular and Quantum Acoustics, Review of Scientific Instruments, Zeitschrift für Physikalische Chemie and others, as well as numerous reports in conference proceedings. These works concerned the following subjects: aqueous solutions of electrolytes, rheological studies of liquids by ultrasound shear waves, in particular viscoelastic relaxation, association in non-aqueous binary mixtures of hydroxyl compounds, water-organic binary mixtures, and properties of pure liquids and liquid mixtures under elevated pressures. Moreover, he is author a few monographs in Polish.
    Majority of the experiments reported by Professor Ernst and members of his group were performed using apparatus developed under his supervision in the last two decades. The most important are precise meters of phase and group speeds of ultrasound, based on the pulse-echo-overlap and sing-around principles. Other research teams in Poland and abroad have used scientific instruments constructed in the laboratory of Professor Ernst also.
    Professor Ernst developed co-operation with Institute of Aviation in Warsaw, Institute of Fundamental Technological Research of the Polish Academy of Sciences, Pedagogical University Erfurt-Mühlhausen, Germany, and University of Rostock, Germany, as well as other scientific institutes. Moreover, he keeps cordial personal relationships and scientific co-operation with colleagues at his Alma Mater, the University of Wrocław.
    The obligation of scientist is to bring up his successors. Professor Ernst promoted 8 doctors, his closest collaborators and followers, one of whom being now habilitated, another one commencing this procedure, and scores of masters (M.Sc.).
    Professor Ernst was awarded the Third Class Prize of the Minister of Education and Higher Schools (1969), the Third Class Prize of the Chairman of the State Council for Peaceful Utilization of Nuclear Energy, the Prize of the Scientific Secretary of the Polish Academy of Sciences (1981), and other distinctions. He is a member of the Committee of Chemistry of the Polish Academy of Sciences. Moreover, he is a member of Polish Acoustical Society and Polish Chemical Society.
    Professor Ernst is a man of high erudition and modesty. As an active academic teacher, he is an exacting supervisor. To work with him under his supervision is a great honour and pleasure for everybody.
    Professor Ernst, best wishes for your 70-th anniversary from all co-workers, both present and former! Edward Zorebski, Wojciech Marczak

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