Field Measurements Of Sound Insulation Research Articles

Towards a simplified model for partially open windows - connecting acoustic and thermal comfort

Traditionally, the internal environmental quality (IEQ) aspects of acoustic and thermal comfort have been considered and designed separately. However, where occupants rely on opening or closing windows to achieve these dimensions, they are not independent in use. To consider both simultaneously, it is crucial to have a simple model of a partially open window that can predict both acoustic and thermal conditions internally. CIBSE TM59 defines the assessment method for adaptive thermal comfort. In the thermal model the ventilation performance of open windows can be described with an "Equivalent Area" (EA). We propose to use the EA to calculate the facade sound insulation based on a simple assessment according to Annex D of ISO 12354-3, i.e. as a facade element with an area of EA and zero sound insulation. This study presents field measurements of sound insulation according to ISO 16283-3 with road traffic sound sources, to evaluate the acoustic uncertainty of using the EA to calculate internal sound levels. Results show encouraging correlation between measurements of element-normalized level difference, Dn,e,w + Ctr and calculations based on the EA. This model is considered adequate for acoustic design purposes, and represents a significant simplification compared with previous proposals.

Modeling field measurements of sound insulation for multi-layered CLT-based floor systems: A means of a prediction model using artificial neural networks

A neural network-based prediction tool is developed to calculate the standardized sound level differences and the standardized impact sound pressure levels for multi-layered CLT-floor systems. The data for this model is derived from 104 sound insulation measurements in one-third-octave bands from 50 Hz to 5 kHz taken from 15 buildings in Europe with different room sizes and functions. The network model is developed using various structural parameters such as floor components, wall types, junction types and interlayers, receiving room volume, surface separating area, and more. The network developed shows good performance in predicting standardized airborne and impact sound insulation curves over all frequencies. The weighted standardized level differences DnTw are estimated with an accuracy of 1 dB, while the standard impact sound pressure level LnTw′ is accurate up to 2 dB. The airborne predictions are correlated in the middle-frequency range (200–1000 Hz), while some deviations may occur in higher frequencies. Impact insulation estimations, on the other hand, are more accurate in the high-frequency range (1.25–5 kHz). A sensitivity study is conducted to understand the model’s dependence on parameters. In both types of estimations, the direct sound path through the floor is the most influential factor, with the flanking paths affecting the results in the second order. Additionally, the volume of the receiving room significantly affects impact estimations at low frequencies. The study’s results also emphasize the importance of a visco-elastic interlayer for accurate airborne predictions in all frequency ranges.

Applicability of ISO 16283-3 for field measurement of sound insulation of partially open windows

Façade sound insulation regulations are typically focused on closed windows. However, many people prefer open windows for ventilation purposes, or simply because of the psychological effect of having an open window. As such it is important to be able to correctly quantify the sound insulation, also with open windows. The international standard ISO 16283-3 describes a field method for test of façade sound insulation of facades or façade elements, e.g. a window, which is further explained in the scope: "The element methods aim to estimate the sound reduction index of a façade element, for example, a window. The most accurate element method uses a loudspeaker as an artificial sound source. Other less accurate element methods use available traffic noise". However, the standard is probably primarily meant for closed windows, and not for open windows. The applicability of ISO 16283-3 for open windows is therefore under investigation for such conditions which are included in an additional Danish environmental noise guideline. Generally, it can be concluded that the traffic noise method is applicable, but care should be taken by using the loudspeaker method for partially open windows, since the results depend highly on the window opening position compared to the loudspeaker position.

Single-number values versus subjective judgment of airborne sound insulation in dwellings

There is a long history of adapting airborne sound insulation in buildings to the actual needs. A first pan-European work was published with COST Action TU0901: Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions in which the differences between the sound insulation measure and the standard sound level difference were documented. Furthermore, ISO 16283-1: Field measurement of sound insulation in buildings and of building elements—Part 1: Airborne sound insulation states: Compared to DnT, R’ has a weaker connection to the subjective impression of airborne sound insulation. To investigate this relationship a simplified listening test and a computer-simulated variation studies of a synthesized airborne sound insulation were carried out. A test sound was generated from a speech, a music, and a noise signal, each of which was filtered by six frequency responses of solid structures. In a paired comparison task, 16 participants judged the loudness of the resulting 18 sounds. The results of the listening test show that perceived loudness is significantly correlated to the single number quantity DnT,w but less to the single number quantity R’w. This finding was confirmed across all signal types. Thus, the results confirm the statement in ISO 16283-1, that the single number quantity DnT,w has a stronger connection to the subjective impression of airborne sound insulation as the quantity R’w.

Validation of the Low-Frequency Procedure for Field Measurement of Façade Sound Insulation

In the ISO 16283 series for field measurement of sound insulation, a low-frequency procedure is specified for determining indoor average sound pressure level, which is the so-called corner method. In the procedure, additional measurements are required in the corners in addition to the default measurements in the central zone, and the indoor average level is corrected with the highest level in the corners. However, this procedure was empirically proposed, and its validity is not fully examined for façade sound insulation. In this paper, detailed experiments were performed in a mock lightweight wooden house for validating the low-frequency procedure for façade sound insulation measurement. The results suggest that a correction with energy-averaging level of all corners is more reliable than with the maximum level, and the uncertainty in the default procedure is sufficiently improved with additional measurements in four non-adjacent corners. Moreover, the effect of the detailed position of the microphone around the corner was clarified for a more specific instruction.

System of national standards for measuring and evaluating sound insulation

The features of international standards being introduced in the Russian Federation in the field of measurement and rating of sound insulation are considered. It has been noted that over the past eight years, on the basis of international standards, a system of fundamental national standards of Russia has been created to measure and evaluate sound insulation in buildings and elements of buildings and structures. The system includes five standards that establish technical methods for laboratory measurements of airborne and impact sound insulation, a standard that establishes approximate methods for field measurements of airborne and impact sound insulation, two standards for a single-number assessment of airborne and impact sound insulation, a standard that sets the rules for determining and application of the uncertainties of sound insulation measurement. In 2018, 2019, on the basis of international standards, drafts of two national standards were prepared on the methods of field measurements of sound insulation of building facades and their elements and sound insulation of airborne sound between two rooms in a building.

Introduction in the Russian federation of international standards in the field of measurement and evaluation of sound insulation

The features of the introduction in the Russian Federation of international standards for measurement and evaluation of sound insulation are considered. Over the past eight years, a system for measuring and evaluating the sound insulation of buildings and their elements has been created on the basis of international standards. In 2012, a series of international standards ISO 10140 for methods of laboratory measurements of airborne and impact sound insulation was introduced as the national standards of Russia GOST R ISO. In 2016, the standards ISO 717 were introduced as modified national standards GOST R 56769-2015 and GOST R 56770-2015, setting the rules for single-number rating of airborne and impact sound insulation. In 2018, the international standard ISO 12999-1 was introduced as a modified national standard GOST R 57900-2017 for determining and applying the uncertainties in measuring sound insulation. In 2019, a draft national standard was prepared for field measurement of sound insulation of facades and their elements, which is a modified edition of the ISO 16283-3. Single-numeric parameters of airborne and impact insulation determined using these standards are subject to comparison with the normative values regulated by the national regulatory document—the set of rules SP 51.13330.

Revision of international standards on field measurements of airborne, impact and facade sound insulation to form the ISO 16283 series

This paper gives the background to the main technical changes concerning the field measurement of sound insulation in the new ISO 16283 series of standards for airborne, impact, and façade sound insulation. These changes were: (1) inclusion of only one-third octave bands without an option for octave band measurements, (2) indication of a preference for standardised (rather than normalised) sound insulation descriptors, (3) introduction of spatial sampling using manual scanning with the operator inside the source and/or receiving room, (4) introduction of a low-frequency procedure for one-third octave bands below 100 Hz in room volumes below 25 m3 using (a) corner measurements to determine the spatial average sound pressure level and (b) the 63 Hz octave band rather than one-third octave bands to measure the reverberation time, (5) alteration of the requirement on the source room spectrum for airborne sound insulation, (6) clarification of the loudspeaker directivity requirements and (7) introduction of the rubber ball as an option for impact sound insulation measurements.

Field Measurements of Sound Insulation in Large, Open Rooms

The international standards governing the measurement of sound insulation in buildings (ISO 140) do not explicitly cover the methodology of taking measurements in large open rooms. A building with open plan floors, each of about 1300 m2, is considered here. The ISO 140-14 standard, through an analysis of sound level distribution, allowed smaller partitions to be identified and used as reference volumes. Different index calculation methods allowed critical issues to be highlighted. The impact sound index was strongly affected by geometry (i.e., volume); therefore, its calculation using different virtual volumes gave differing results. Furthermore, the index calculated using the logarithmic average of the indices for each virtual volume and an extended analysis of measurements over the entire floor provided different results. The airborne sound insulation index was demonstrated to be independent of the choice of virtual volumes; it could be consistently calculated using either the logarithmic average or the extended analysis.

Uncertainty analysis by a Round Robin Test of field measurements of sound insulation in buildings: Single numbers and low frequency bands evaluation - Airborne sound insulation

The uncertainty of field measurements of a lightweight wall and a heavy floor was analysed by Round Robin Test (RRT), conducted in a full-scale experimental building at ITC-CNR. Each of the 9 teams involved in the I-RRT replicates the tests 5 times, for a total of 45 measurements, while the repetitions of reverberation time were 110. Both for sound insulation and reverberation time the main variations are in the low frequency range. The differences between D, R', Dn and DnT and their reproducibility and repeatability standard deviations values were also analysed. The study is also focused on the single numbers evaluation: true value and uncertainty. Single numbers were evaluated in both narrow and extended range. The extension to low frequencies implies a variation in single number values that reaches its maximum in the case of X +Ctr in the extended range. This is because this index is the most influenced by low frequencies. Thus the measurement uncertainty at low frequencies has to be more deeply investigated, before including the low frequency range in the on-field measurements

Measurement of room‐to‐room airborne sound insulation with an access floor in a dwelling unit of condominium

It is preferred covering a wooden access floor on the concrete floor for condominium apartments in Japan. The access floor usually installed after every partition in each dwelling unit. If access floor and ceiling were done before partition, one can obtain accuracy of construction and reduce waste material. Therefore, one can provide building more green. But, there is concern that may deteriorate sound insulation because of flanking path through under the access floor. On the other hand, there is also another dominant flanking path irrespectively to these construction methods: via doors leading into hallway. A number of field measurements of sound insulation were done with opening/closing doors to evaluate the flanking transmission via the doors. These results show that the doors affect especially in high frequency, but not significant in low‐mid frequency. Next, the sound transmission performances of access floors and ceilings measured at laboratory are compared with direct sound transmission through wall itself. As a conclusion, field measurement results show that this construction method difference less affect to airborne sound insulation performance.

Uncertainty of measured and calculated sound insulation in buildings - Results of a Round Robin Test

An inter-laboratory comparison has been made in situ with the participation of 8 laboratories. The operators measured airborne and impact sound insulation of 7 partitions according to the ISO 140 standards and some additional guidelines. Variations of sound insulation, and their components, have been analyzed. In addition, field measurements of sound insulation in 40 building cases were compared to calculations according to EN 12354 (-1, -2). Safety margins for predictions of 3 dB are recommended for calculation of heavy building partitions, with respect to an estimated risk of 5% being disapproved by a sample measurement in situ.

Overview of the Field Measurement of Sound Insulation of Facades and Facade Elements

Overview of the Field Measurement of Sound Insulation of Facades and Facade Elements

Sound isolation—A review

When treating the property of sound attenuation provided by partitions, different ways are found for its specification. In this paper most common descriptors employed to specify airborne and structureborne sound insulation are summarized and reviewed. Advantages and disadvantages of single-number specifications for sound insulation are commented upon. On the other hand, emphasis is made as to the importance and convenience of field measurements of sound insulation, even though they are time-consuming. Also included is a brief description of the situation prevailing in some countries, Mexico among them, regarding minimum sound insulation requirements between dwellings. Finally, reference is made to the use of acoustic intensity techniques for the measurement of sound insulation and the need of standardization on this type of evaluation.

Field Measurement of Sound Insulation between Rooms by a Standerdized Sound Source

Field Measurement of Sound Insulation between Rooms by a Standerdized Sound Source

Field Measurement of Sound Insulation of Windows by the Integration Method of Sound Energy

Field Measurement of Sound Insulation of Windows by the Integration Method of Sound Energy