The research, of which this article is a part, deals with the design, implementation and verification of the methodology of measuring the transmission of vibro-sound energy from the contact of the tread profile with the rail through the primary suspension blocks, side bearers, bogie pivot and brake system to the tank shell and measuring the generation of sound energy by the wagon bogie. It analyses the frequency distribution of vibro-sound energy of individual blocks (components) of the tank wagon and the intensity of vibration transmission by these blocks until the mounting of the tank shell. Using frequency spectra, the transmission loss of individual bogie blocks and tank at a maximum speed of 120 km/h is displayed. The measurement methodology, measured amplitudes and frequency distribution of vibrations and noise in motion are the basis for reducing the vibro-sound energy not only of the developed prototype tank wagon, but also of railway wagons with a similar bogie. As part of scientific research, the proposed methodology was also successfully applied to solving the dynamic load of high-speed spinning headstocks used in the textile industry.

Effective wood evaluation necessitates a thorough consideration of technical parameters, including both quantitative and qualitative features. The study aimed to practically verify the accuracy and applicability of the ARBOTOM acoustic stress tomograph under various forestry operations and research conditions. The tomograph was tested in a forest stand and a poplar plantation. A total of 165 standing tree trunks were evaluated using the acoustic tomograph: 108 oaks, 53 lindens, 4 pines, 1 fir in the forest, and 2 poplar trunks at the plantation. The median value for damage identified in the red color spectrum was 41.4% for oak and 58.3% for linden. In the violet color spectrum, the median values for damage were 13.75% for oak and 9.5% for linden. The results also indicated that the number of sensors did not significantly affect the identification of the extent of red or violet damage zones. The application on poplar trunks showed that the tomograph is not suitable for very thin trunks with naturally thinner wood. Integrating these technologies into forestry operations could help create favorable conditions for the use of modern information technologies in conjunction with the sustainable management of forest resources.

In this article, we present a concert hall of The Fatra House of Arts in Zilina Slovakia, describe the hall itself and examine the acoustical quality of the hall. The concert hall primarily serves for symphony, chamber orchestra and soloist but hosts various cultural and social events as well. The hall is being considered as acoustically exquisite space by many professional musicians and conductors all around the world for a long time. However, real measurement of the objective acoustical quality parameters, that could confirm the subjective assessment, has never been carried out. We conducted the acoustic measurements following the ISO 3382 standard, which specifies methods for evaluating room acoustics using impulse response analysis. The measurements were performed using an omnidirectional sound source and an omnidirectional microphone to capture the room’s impulse responses at multiple receiver positions. From these responses, we assessed reverberation-based (reverberation time, early decay time), energy-based (clarity), spectral-based (bass ratio, treble ratio), and spatial impression-based (lateral energy fraction) objective criteria. The measured results of these parameters demonstrate a correlation with the recommended values found in specialized literature for chamber orchestra performances, with a reverberation time of 2 s, an early decay time of 1.57 s, a clarity of 0.8 dB, and an initial time delay gap of 12 ms.

This study focuses on the attenuation characteristics of the wave that propagates on the basilar membrane. The basilar membrane wave, which occurs from the interaction between the basilar membrane and fluid, plays a major role in the hearing system. Because the mass and stiffness of the basilar membrane are graded along its length, the basilar membrane wave peaks at a specific region along the cochlea depending on the acoustic wave frequency. We took the viscosity of the fluid into consideration and investigated the wave characteristics by conducting modal analysis. We found that the attenuation curve of the basilar membrane wave has an inflection point and the frequency-position function obtained from the inflection points matches well with the Greenwood function. This suggests that the mode of the basilar membrane wave drastically changes before and after the peak point.

This study investigates the transmission of structure-borne noise generated by water supply installations, with a particular focus on faucets. Laboratory experiments were conducted to evaluate the effects of various pipe fixing methods, wall elbow supports, and faucet types on noise levels. The measurements revealed that PPR clamps and rubber-lined clamps transmit varying degrees of noise depending on hydraulic shocks and water flow rates. Free-hanging pipes consistently demonstrated a significant noise reduction of up to 11.0 dB. The impact of wall elbow support and its attachment to the partition wall also proved critical, with complete removal reducing noise by up to 15.4 dB. The findings emphasize the role of minor construction details in noise transmission and suggest practical strategies to mitigate noise from plumbing systems, particularly in new residential buildings where irregular layouts exacerbate the issue. These results offer valuable insights for improving acoustic standards and minimizing noise complaints in modern housing developments.

Environmental noise, particularly road traffic noise, has been considered one of the most widespread environmental pollutants. The primary aim of this study was a 30-year longitudinal investigation of road traffic noise annoyance trends in a model region - Bratislava’s continuously monitored neighbourhoods, with data collected at 10-year intervals. Using validated methods to assess noise annoyance and psychosocial well-being, along with direct sound level measurements, the study analysed responses from 3 197 university students residing in exposed and control areas. Results showed a significant rise in traffic noise burden in exposed areas from 1989 to 1999 (L Aeq = 67.5 dB), a slight decrease by 2019 (L Aeq = 63.9 dB), and further reduction during lockdowns (L Aeq = 62.5 dB). At the control site, noise levels significantly decreased from L Aeq = 50.2 dB in 2019 to L Aeq = 46 dB in 2020. Road traffic noise annoyance initially rose sharply, with ORMH values increasing from 2.56 to 6.01 over the first 10-year interval, gradually declining to ORMH 3.26 by 2023. Despite this trend, road traffic noise annoyance remains a concern, highlighting the need for preventive measures and healthier urban transport solutions.

The paper is devoted to the acoustic analysis of a historical bell made in 1772. The paper presents basic measurements of the acoustic-vibrational characteristics of a small bell with subsequent analysis of selected parameters. Methods of analysis in the time, frequency and time-frequency domains were selected for the analysis. The conclusion presents an evaluation of the measurement method and evaluation. It also includes recommendations for further types of measurements and investigations.

his paper presents a case study focusing on the vibrations of a ribbon loudspeaker’s strip. These vibrations induce surface deformation, resulting in a degradation of the reproduced sound quality. The phenomenon is briefly reviewed, and the theoretical foundations are outlined. Several modes of the loudspeaker’s strip are analyzed using 3D and 2D simulations conducted in Matlab® and COMSOL Multiphysics. A video recording has been done that visually demonstrates the specific modes that were theoretically calculated. Conclusions drawn from the mode analysis are applicable to the design and manufacturing of loudspeakers

The sound quality of a xylophone depends on the material it is made of. The xylophone produces sound through the vibration of the wooden bars. The bars are usually made of rosewood or padauk due to their properties, resonance, and durability. However, the Honduran rosewood is a protected wood species, so it is necessary to look for other suitable wood species. Based on the investigation of the physical and acoustical characteristics of the various wood species, it appears that the European mountain ash (also known as rowan) may be a suitable substitute for the Honduran rosewood. Unlike the Honduran rosewood, the European ash is not listed in the CITES appendices or on the IUCN Red List of Threatened Species. The effect of modification of the European mountain ash on the physical and acoustical characteristics (PACHs) and sound quality was investigated. The wood samples were modified in two ways: mechanical densification and a combination of mechanical densification and thermal modification. The PACHs (density of wood ρ w, modulus of elasticity along the wood grain EL , acoustical constant A, loss coefficient η, specific modulus of elasticity E esp, acoustic conversion efficiency ACE, speed of sound along the wood grain cL ) were measured before and after modification.These PACHs were compared with the characteristics of the Honduran rosewood. The sound quality of the xylophone bars produced before and after modification was also determined. Following the experiment results it can be stated that the wood of the European mountain ash, after combination mechanical densification and thermal modification, can be used as an alternative to the Honduran rosewood for the xylophones of lower quality.

One of the ways we can motivate young people is by implementing Children’s Universities as a form of motivating young people for future studies in science and technology. Young people expect a wide use of information and communication technologies in education. They are eager to work actively and implement their own ideas. Children up to the age of 10 undoubtedly have a real but hidden interest in natural and technical sciences, they want to become scientists and explorers. However, after a few years of education at the primary level, the situation changes completely. Simple acoustic experiments included in the teaching from the lowest levels of the education system stimulate children from early childhood to explore and lead from initial play to subsequent experimentation and discovery of new knowledge. Initial playful experimentation that involves multiple child senses (hearing, sight, and touch) stimulates experimentation at the time of primary education and later at the time of secondary and tertiary education in technical universities motivates analysis and evaluation at higher levels of cognitive goals according to Bloom’s taxonomy.