Estimation of the Reduction in Impact Sound Pressure Level of Floating Floors from the Dynamic Stiffness of Insulation Layers

1996 ◽  
Vol 3 (1) ◽  
pp. 33-53 ◽  
Author(s):  
H.A. Metzen

The most relevant parameter for assessing the acoustical properties of insulation layers for floating floor applications is the dynamic stiffness. Besides the surface mass of the floor plate the dynamic stiffness influences the reduction in impact sound pressure level of a floating floor. According to the formerly German measurement standard DIN 52214 the dynamic stiffness of impact sound insulation materials had to be measured after applying a short-term pre-load of 50 kNm−2. This pre-load does not reflect the conditions in the field and has been withdrawn in EN 29052-I. By comparison of measured field data for floor constructions with estimated data based on measurements with and without pre-load it is shown, that the new measurement procedure in connection with a more detailed estimation of the building element properties leads to a more accurate prediction of impact sound insulation in dwellings.

2020 ◽  
Vol 18 (2) ◽  
pp. 1451-1463
Author(s):  
Witold Mikulski

Abstract Purpose The purpose of the research is to work out a method for determining the sound insulation of acoustic enclosures for industrial sources emitting noise in the frequency range of 10–40 kHz and apply the method to measure the sound insulation of acoustic enclosures build of different materials. Methods The method is developed by appropriate adaptation of techniques applicable currently for sound frequencies of up to 10 kHz. The sound insulation of example enclosures is determined with the use of this newly developed method. Results The research results indicate that enclosures (made of polycarbonate, plexiglass, sheet aluminium, sheet steel, plywood, and composite materials) enable reducing the sound pressure level in the environment for the frequency of 10 kHz by 19–25 dB with the reduction increasing to 40–48 dB for the frequency of 40 Hz. The sound insulation of acoustic enclosures with a sound-absorbing material inside reaches about 38 dB for the frequency of 10 kHz and about 63 dB for the frequency of 40 kHz. Conclusion Some pieces of equipment installed in the work environment are sources of noise emitted in the 10–40 kHz frequency range with the intensity which can be high enough to be harmful to humans. The most effective technical reduction of the associated risks are acoustic enclosures for such noise sources. The sound pressure level reduction obtained after provision of an enclosure depends on its design (shape, size, material, and thickness of walls) and the noise source frequency spectrum. Realistically available noise reduction values may exceed 60 dB.


Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 903 ◽  
Author(s):  
Juan M. Navarro ◽  
Raquel Martínez-España ◽  
Andrés Bueno-Crespo ◽  
Ramón Martínez ◽  
José M. Cecilia

Wireless acoustic sensor networks are nowadays an essential tool for noise pollution monitoring and managing in cities. The increased computing capacity of the nodes that create the network is allowing the addition of processing algorithms and artificial intelligence that provide more information about the sound sources and environment, e.g., detect sound events or calculate loudness. Several models to predict sound pressure levels in cities are available, mainly road, railway and aerial traffic noise. However, these models are mostly based in auxiliary data, e.g., vehicles flow or street geometry, and predict equivalent levels for a temporal long-term. Therefore, forecasting of temporal short-term sound levels could be a helpful tool for urban planners and managers. In this work, a Long Short-Term Memory (LSTM) deep neural network technique is proposed to model temporal behavior of sound levels at a certain location, both sound pressure level and loudness level, in order to predict near-time future values. The proposed technique can be trained for and integrated in every node of a sensor network to provide novel functionalities, e.g., a method of early warning against noise pollution and of backup in case of node or network malfunction. To validate this approach, one-minute period equivalent sound levels, captured in a two-month measurement campaign by a node of a deployed network of acoustic sensors, have been used to train it and to obtain different forecasting models. Assessments of the developed LSTM models and Auto regressive integrated moving average models were performed to predict sound levels for several time periods, from 1 to 60 min. Comparison of the results show that the LSTM models outperform the statistics-based models. In general, the LSTM models achieve a prediction of values with a mean square error less than 4.3 dB for sound pressure level and less than 2 phons for loudness. Moreover, the goodness of fit of the LSTM models and the behavior pattern of the data in terms of prediction of sound levels are satisfactory.


2005 ◽  
Vol 12 (2) ◽  
pp. 99-113 ◽  
Author(s):  
Alessandro Schiavi ◽  
Andrea Pavoni Belli ◽  
Francesco Russo

This paper describes a procedure for evaluating the reduction in impact sound pressure level of floating floors by measuring the apparent dynamic stiffness of the resilient layer, according to International Standard EN 29052-1. The impact sound pressure level experimental data, obtained according to International Standard UNI EN ISO 140-8, was compared with estimates obtained from dynamic stiffness measurements. Results confirm the effectiveness of the empirical model. Two questions are addressed. The first concerns the decrease in layer thickness over time. The second concerns the relationship between damping ratio and performance.


2012 ◽  
Vol 18 (3) ◽  
pp. 386-392
Author(s):  
Modestas Kligys ◽  
Marijonas Sinica ◽  
Georgijus Sezemanas ◽  
Kęstutis Miškinis ◽  
Saulius Vaitkus

The paper describes the study on the operational properties of lightweight composite with density of 150–350 kg/m3. It was established that these properties depend on the ratio of porous cement matrix and inclusions of crushed expanded polystyrene packing tare waste per unit volume of the lightweight composite. Studies have demonstrated that when the density of lightweight composite varies in the above mentioned limits, the compressibility amounts to 2.4–0.8 mm, point load – 0.38–3.39 kN, dynamic stiffness – 35–135 MN/m3, and reduction in normalised impact sound pressure level – 26–17 dB. The dependences between the established properties and the density of lightweight composite are showed in the equations of regression. Possible versions for the use of lightweight composite in different constructions of floors and roofs are also provided.


Author(s):  
Fumio Shimizu ◽  
Kazuhiro Tanaka ◽  
Koji Yamamoto ◽  
Hiroshi Shigefuji

The noise and vibration control are the one of important issues. A soundproof barrier, which covers a sound source with sound absorbing materials, is very useful for the noise reduction. When large noise and high temperature heat emit from the sound source, we must also consider the heat radiation as well as the noise reduction. The purpose of the present study is to investigate the relationship between sound pressure level and vibration on a soundproof barrier around a sound source. The effect of heat radiation hole on the sound insulation performance of the soundproof barrier is also investigated. The sound pressure level and the vibration displacement were similarly distributed on the surface of the barrier. Therefore, the vibration of the barrier was strongly influenced to the sound pressure level of the transmitted sound.


2020 ◽  
Vol 68 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Barry Marshall Gibbs ◽  
Michel Villot

This article coincides with recent publications of international standards, which provide methods of predicting the performance of both heavyweight and lightweight buildings in terms of airborne sound insulation and impact sound isolation, from the performance of individual elements such as walls and floors. The performances of the elements are characterized by the sound reduction index and the impact sound pressure level. To predict the sound pressure level due to vibrating sources (i.e., mechanical installations, water services and other appliances), source data are required in a form appropriate as input for prediction models similar to the above, i.e., as equivalent single quantities and frequency band-averaged values. Three quantities are required for estimating the structure-borne power for a wide range of installation conditions: activity (the free velocity or the blocked force of the operating source), source mobility (or the inverse, impedance) and receiver mobility (or impedance) of the connected building element. Methods are described for obtaining these source quantities, including by using laboratory reception plates. The article concludes with a proposed database, based on laboratory measurements and simple mobility calculations, which provides a practical approach to predicting structureborne sound in buildings.


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