ARCHIVES OF ACOUSTICS Copyright c 2018 by PAN – IPPT Vol. 43, No. 3, pp. 545–577 (2018) DOI: 10.24425/123927 JOINT CONFERENCE – ACOUSTICS 2018 65th Open Seminar on Acoustics 35th Symposium on Hydroacoustics Polish-German Structured Conference on Acoustics Ustka, Poland, September 11 – 14, 2018 Abstracts Kasgen¨ Johannes, Matthias Michael Millitzer Jonathan, Perfetto Sara Low Noise Pavements in Germany: Division Smart Structures, Fraunhofer LBF Established Concepts and New Ideas Darmstadt, Germany Altreuther Beate, [email protected] Demands on the development of ship propulsion sys- Maennel Manuel, [email protected] tems are an increase of efficiency and its vibro-acoustic Mueller-BBM GmbH Planegg behaviour. The paper gives an overview of the develop- Munich, Germany ment methodology of active measures to reduce torsional and translational vibration of a ship propulsion system. Traffic noise, and road traffic noise in particular, is Based on experimental investigation of a ship, a numeri- a problem to be solved in densely populated regions world- cal model of the propulsion system is setup and updated wide. Tire-road noise is the main source for road traffic by experimental results. The simulation model includes noise and low-noise road surfaces are an effective mea- the rotational and translational vibration behaviour. The sure for its reduction. In Germany, most low-noise surfaces model structure follows an admittance-impedance descrip- are built in asphalt, giving a good acoustic performance tion that is most suitable for the design of active vibra- whereas their durability under heavy traffic is not optimal. tion control systems. Different concepts for reducing vi- Concrete, instead, is very durable and ideal for roads under bration are evaluated and compared numerically compared. heavy traffic, but there are only a few concepts of low noise The realized systems are characterized in a propulsion sys- concrete road types. In several research projects a number tem testing environment and eventually implemented in the of low-noise concrete road surface concepts have been in- real ship. Examples of realized measures as an inertial mass vestigated, including the optimization of standard road sur- actuator and an energy-harvesting absorber are presented. faces like exposed aggregate concrete or the postprocessing of concrete roads by diamond grinding. In addition, sev- ??? eral new surface types have been developed from a virtual design, taking into account the deeper understanding of Decibel Algebra in Acoustics tire-road noise generation: these concepts include specif- Batko Wojciech ically designed road surface textures, novel materials for Faculty of Mechanical Engineering and Robotics road construction such as ultrahigh performance concrete AGH University of Science and Technology or specially designed porous materials. Kraków, Poland The paper resumes the well-established low noise road surface concepts used in Germany and the outcomes of the ??? above-mentioned research projects. Digitally Controlled PA-Systems in Churches ??? Behler Gottfried, [email protected] Active Vibration Reduction RWTH-Aachen University of Ship Propulsion Systems Aachen, Germany Bartel Torsten, [email protected] Room-acoustic conditions in churches, especially in old Herold Sven, Infante Francesco large churches protected as buildings of historic impor- 546 Archives of Acoustics – Volume 43, Number 3, 2018 tance, may not be a favourite for speech intelligibility. The Hopping Discrete Fourier Transform to Speed Therefore, speech enhancement systems are a requirement. Up Convergence of a Frequency-Domain Active A typical low cost solution is to install column loudspeaker Noise Control System systems with highly directed radiation. Unfortunately, the Bismor Dariusz, [email protected] directivity always points out perpendicularly from the cen- tre of the column, which in many applications leads to Institute of Automatic Control a tilting of the column. Moreover, a frequency independent Silesian University of Technology directivity becomes difficult to achieve and the overall re- Gliwice, Poland sponse in many cases is not satisfying. Frequency-domain least mean square (FDLMS) algo- To overcome these limitations a novel design with digi- rithm is a good alternative to traditional, time-domain pro- tally controlled loudspeaker columns is available since sev- cessing. It requires less computational demand and offers eral years and leads to a much better coverage. Due to a possibility to individually adjust the convergence speed the better steering of the sound distribution in space the of different frequency components. Moreover, it allows to number of loudspeakers can be reduced drastically thus re- shape the frequency response of an adaptive filter easily. ducing the interference with the preservation order. The classical implementation of the FDLMS uses a block In this paper, the result of three different PA system size of double the adaptive filter length to avoid the circu- designs will be discussed which were installed in the Cathe- lar effects. Considering that active noise control systems use dral of Cologne, the Cathedral of M¨unsterand a Baroque long adaptive filters, and that the update of the filter coef- Church in M¨unster. ficients is once per the block size, this implies the update is not performed very often and introduces an unwanted time ??? delay in the control path. However, it is possible to adjust the block size to values different than double the adaptive Ultrasonic Studies on Pickering Emulsion filter length. The negative aspect of this attitude is that the Formation Process growth of the computational demand. The use of real-time Bielas Rafał, [email protected] discrete Fourier transform algorithms allows to fight this Józefczak Arkadiusz negative effect. Rozynek Zbigniew ??? Adam Mickiewicz University Poznań, Poland Feedback Loops in Models of the Auditory System Blauert Jens, [email protected] ??? Ruhr-Universit¨atBochum Acoustic Data Analysis for the Assessment Inst. f¨urKommunikationsakustik of Wood Boring Insects’ Activity Bochum, Germany Bilski Piotr1, [email protected] Current advanced models of the auditory system con- Krajewski Adam2, adam [email protected] sist of an intelligent network of signal-driven (bottom-up) Witomski Piotr2, piotr [email protected] and hypothesis-driven (top-down) algorithms. These sys- Bobiński Piotr1, [email protected] tems are built to identify and characterize auditory objects Lewandowski Marcin1, [email protected] and to interpret and understand auditory scenes. Among 1 Institute of Radioelectronics other things, this enables them to help plan and initiate and Multimedia Technology appropriate actions. Further, they are able to make judg- Warsaw University of Technology ments – for example, on the quality of experience in spaces Warszawa, Poland for musical performances. To achieve these goals, adequate 2 Department of Wood Science and Wood Protection feedback loops have to be considered, simulated, and im- Warsaw University of Life Sciences plemented. In this talk, the basic architecture of such an Warszawa, Poland advanced model is presented and some feedback loops that have already been realized and evaluated are described and The following paper presents the methodology for the discussed. acoustic analysis of the wood boring insects activity. Their ??? detection in the consumer wood has significant economic impact. The most important is the measurement of energy Comparison the Beamforming Method generated by the larvae feeding on the piece of wood. To de- with Standard Acoustics Measurements tect the candidate sounds, the moving narrow time window in Industrial Environment was implemented. The analysis was performed in the noisy Bogusławski Grzegorz, grzegorz.boguslawski@p.Łódź.pl environment, therefore the Support Vector Machine clas- Gralewski Jacek, jacek.gralewski@p.Łódź.pl sifier was used to distinguish between the larva-generated Kopania Joanna, joanna.kopania@p.Łódź.pl sounds and all other coming from the environment. Results show the usefulness of the approach to assess the larvae ac- Institute of Social Sciences and Management tivity based on the measurement of intensity and energy of of Technologies sounds generated by them. Faculty Committee on Teaching and Learning Łódź University of Technology ??? Łódź, Poland Chronicle – Joint Conference – ACOUSTICS 2018 547 Characterizing the source of noise from a machine is This study is a part of larger study which examines an important task for manufacturers of consumer goods. the thermophysical (acoustic, volumetric, conductometric, The main problem is often related to the industrial envi- refractometric and viscosimetric) properties of selected im- ronment, in which the noise level is results from many pro- idazolium ionic liquids in various molecular solvents. Den- duction processes occurring simultaneously. There are sev- sities and sound velocities of 1-butyl-3-methylimidazolium eral measurement methods for measuring the sound level of tetrafluoroborate in two different solvents, protic methanol acoustic source. The conducting research to develop noise and aprotic N,N-dimethylacetamide have been measured. controls for production process involves: 1) noise source The studies were conducted in dilute solutions at temper- identification; 2) development of noise controls; 3) evalua- atures ranging from (283.15 to 318.15) K and atmospheric tion of the developed noise controls. In this work the appli-