Giovanni Zambon

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

DYNAMAP – Development of low cost sensors networks for real time noise mapping

Abstract The Environmental Noise Directive (END) requires that regular updating of noise maps is implemented every five years to check and report about the changes occurred during the reference period. The updating process is usually achieved using a standardized approach, consisting in collating and processing information through acoustic models to produce the updated maps. This procedure is time consuming and costly, and has a significant impact on the budget of the authorities responsible for providing the maps. Furthermore, END requires that simplified and easy-to-read noise maps are made available to inform the public about noise levels and actions to be undertaken by local and central authorities to reduce noise impacts. To make the updating of noisemaps easier and more cost effective, there is a need for integrated systems that incorporate real-time measurement and processing to assess the acoustic impact of noise sources. To that end, a dedicated project, named DYNAMAP (DYNamic Acoustic MAPping), has been proposed and co-financed in the framework of the LIFE 2013 program, with the aim to develop a dynamic noise mapping system able to detect and represent in real time the acoustic impact of road infrastructures. In this paper, after a comprehensive description of the project idea, objectives and expected results, the most important steps to achieve the ultimate goal are described.

The Milan agglomeration Strategic Noise Map

The aim of this paper is to describe the procedure used for the Milan agglomeration Strategic Noise Mapping, as defined by Environmental Noise Directive (2002/49/EC). City of Milan is a complex case study because of the presence of a plurality of sources: road traffic, railway traffic (also tram traffic) and aircraft noise (Linate airport). The assessment method is based on the guidelines contained in the Good Practice Guide for Strategic Noise Mapping and the Production of Associated Data on Noise Exposure (WG‐AEN). The study of noise generated from several sources was carried out with the integrated use of both numerical models and Geographic Information Systems (GIS). Numerical models allow us to estimate of noise levels in large areas near to a specific noise source and GIS enable the efficient acquisition, management and elaboration of geo‐referenced data representative of territory, sources and buildings. By means of the study of specific GIS application it was possible to predict the global noise...

Predicting Hourly Traflc Noise from Traflc Flow Rate Model: Underlying Concepts for the DYNAMAP Project

Abstract The DYNAMAP project aims at obtaining a dynamic noise map of a large residential area such as the City of Milan (Italy), by recording traffic noise from a limited number of noise sensors. To this end,we perform a statistical analysis of road stretches and group them into different clusters showing a similar measured hourly traffic noise behavior. In the sameway,we group simulated hourly traffic flow rates and compare their compositions with those of the traffic noise groups. The best agreement with the traffic noise was found by using the so-called normal traffic flow rate, yielding overlaps between 68 and 97%. Finally, we derive a simple analytical model to predict the hourly traffic noise from the simulated normal traffic flow, in very good agreement with the measured values.

Effect of room partitions on airborne and impact sound insulation in large, open rooms

ISO 16283 for measuring sound insulation in buildings supersedes ISO 140 but is particularly lacking for measurements in large, open rooms of the type considered here (floor volume: ~4000u2009m3). Following ISO 16283-1, the room volume is theoretically divided into smaller volumes through an analysis of sound level distribution. Large absorbing panels in the ceiling prevent the growth of diffuse sound fields, and thus, the analysis makes critical use of normalization factors used in the airborne sound insulation and impact noise levels based on the Sabine equation. Given the likely division of finished floors into rooms, mobile separation walls are used here to investigate the influence of partitions on sound insulation. The results seem to show that they reduce sound insulation and increase impact noise level in each considered enclosed volume. These variations were investigated further through measurements taken in two volumes of different dimensions and at positions near to and far away from the separation walls.

Field measurements of acoustic performance in buildings: a Round Robin Test

This paper presents the experimental results of a round robin test performed on the same building by different teams working with three independent bodies: a research body, ITC‐CNR, a university laboratory DISAT and the Regional Agency for Environment Protection of Lombardy, ARPA. A partition wall (the airborne sound insulation between rooms), a floor (the impact sound insulation between rooms) and a facade (the insulation of the facade against outdoor sound) were tested, using the measurement methods given in the relevant parts of the ISO 140 series. The accuracy of acoustic measurement methods in buildings depends on many factors. In this round robin test, the situation (varying from straightforward rectangular rooms to half open spaces with all kind of shapes) and the construction details were kept fix. The analysis was aimed at investigating the influence of the operating condition of the equipment (repeatable settings) and the reproducibility, using different types of acoustic instrumentation and var...

Noise Mapping of major roads in Milan District

The paper deals with noise map calculation, according to the first deadline of the END (Environmental Noise Directive, 2002/49/EC), for Milan district major roads. The roads with more than six million vehicle passages per year have been estimated to cover 405 km out of 1090 km total. Noise emission has been calculated from peak hour flow data for each segment of the whole road network and from some local traffic direct measurements. A statistical method to assign mean flow values to each road segment has been used, according to Italian reference periods. These data enable to use an acoustic model on a wide area with several line sources in order to obtain noise propagation maps of Lden and Lnight indicators. A procedure to estimate people exposed to different noise levels, as required by the END, has been also studied. Through a geographic information system it has been possible to intersect population input data (demographic density for different areas, buildings use type and buildings volumetric data) and noise mapping data. Every step of the procedure has been carried out complying with WG‐AEN Good Practice Guide recommendations, on the basis of the best available data in Milan district.