Caracterització de l'impacte dels esdeveniments acústics en els nivells equivalents sonors i en la percepció dels ciutadans per a la confecció de mapes dinàmics de soroll

La contaminació acústica ha esdevingut un greu problema de salut pública, provocant diversos tipus de malalties i trastorns en les persones. Segons l'Organització Mundial de la Salut, cada any es perden a l'Europa occidental, un milió d'anys de vida saludables per culpa de l'exposició al soroll ambiental. Per tal d'avaluar i gestionar el soroll ambiental a la Unió Europea, la directiva END 2002/49/CE requereix als estats membres la preparació i publicació de mapes de soroll actualitzats i els plans d'acció relatius, cada cinc anys. Això inclou aglomeracions de més de 100.000 habitants i les principals carreteres, vies de tren i aeroports. Gràcies als avanços tecnològics recents, el paradigma de creació de mapes de soroll ha canviat substancialment, permetent l'automatització de les mesures dels nivells sonors utilitzant xarxes de sensors acústics sense fils per a la generació de mapes de soroll en temps real. Així i tot, aquestes xarxes no poden prevenir una sèrie de situacions que esbiaixarien la mesura real dels nivells equivalents sonors, ocasionant que el mapa no sigui fidel a la realitat que percep el ciutadà, p. ex., el so de les aus, de la indústria, els clàxons, les sirenes, les converses que ocorren prop dels sensors o fenòmens meteorològics com la pluja i el vent. Aquesta tesi estudia la caracterització dels esdeveniments acústics per a la confecció de mapes dinàmics de soroll de trànsit. L'estudi comença presentant el context de la tesi, el projecte LIFE DYNAMAP, que pretén mesurar els nivells de soroll de trànsit en dues àrees pilot i integrar-los dinàmicament en un mapa de soroll que s'actualitza a temps real. A continuació, es presenta una anàlisi exhaustiva dels esdeveniments que es troben en les dues àrees, la urbana i la suburbana, i s'hi apliquen diverses caracteritzacions. Una de les mesures que es presenta és la de l'impacte en el nivell equivalent sonor (Leq), que permet mesurar el biaix que provoca la presència de certs esdeveniments acústics en la confecció dels mapes de soroll de trànsit. També es planteja l'ús de tests perceptius mitjançant mètriques psicoacústiques per tal d'adaptar la caracterització d'aquests esdeveniments a la percepció ciutadana. L'objectiu principal de la tesi és caracteritzar els esdeveniments d'entorns urbans i suburbans per oferir mapes de soroll més fidels a la realitat percebuda pel ciutadà en relació amb el paisatge sonor on es troba. I durant la tesi es mostra la importància de la detecció de sons en una xarxa de sensors acústics per tal de prevenir errors de mesura en els nivells equivalents i la necessitat d'entrenar el sistema de detecció amb dades obtingudes en els mateixos sensors de la xarxa.La contaminación acústica se ha convertido en un grave problema de salud pública, provocando varios tipos de enfermedades y trastornos en las personas. Según la Organización Mundial de la Salud, cada año se pierden en la Europa occidental, un millón de años de vida saludables por culpa de la exposición al ruido ambiental. Para evaluar y gestionar el ruido ambiental en la Unión Europea, la directiva END 2002/49/CE requiere a los estados miembros la preparación y publicación de mapas de ruido actualizados y los planes de acción relativos, cada cinco años. Esto incluye aglomeraciones de más de 100.000 habitantes y las principales carreteras, vías de tren y aeropuertos. Gracias a los avances tecnológicos recientes, el paradigma de creación de mapas de ruido ha cambiado sustancialmente, permitiendo la automatización de las medidas de los niveles sonoros utilizando redes de sensores acústicos inalámbricos para la generación de mapas de ruido en tiempo real. Aun así, estas redes no pueden prevenir una serie de situaciones que sesgarían la medida real de los niveles equivalentes sonoros, ocasionando que el mapa no sea fiel a la realidad que percibe el ciudadano, p. ej., el sonido de las aves, de la industria, los cláxones, las sirenas, las conversaciones que ocurren cerca de los sensores o fenómenos meteorológicos como la lluvia y el viento. Esta tesis estudia la caracterización de los eventos acústicos para la confección de mapas dinámicos de ruido de tráfico. El estudio empieza presentando el contexto de la tesis, el proyecto LIFE DYNAMAP, que pretende mesurar los niveles de ruido de tráfico en dos áreas piloto e integrarlos dinámicamente en un mapa de ruido que se actualiza a tiempo real. A continuación, se presenta un análisis exhaustivo de los acontecimientos que se encuentran en las dos áreas, la urbana y la suburbana, y se aplican varias caracterizaciones. Una de las medidas que se presenta es la del impacto en el nivel equivalente sonoro (Leq), que permite mesurar el sesgo que provoca la presencia de ciertos acontecimientos acústicos en la confección de los mapas de ruido de tráfico. También se plantea el uso de macetas perceptivas mediante métricas psicoacústicas para adaptar la caracterización de estos eventos a la percepción ciudadana. El objetivo principal de la tesis es caracterizar los acontecimientos de entornos urbanos y suburbanos para ofrecer mapas de ruido más fieles a la realidad percibida por el ciudadano en relación con el paisaje sonoro donde se encuentra. Y durante la tesis se muestra la importancia de la detección de sonidos en una red de sensores acústicos para prevenir errores de medida en los niveles equivalentes y la necesidad de entrenar el sistema de detección con datos obtenidos en los mismos sensores de la red.Acoustic pollution has become a serious public health problem, causing various types of disease and disorders in people. According to the World Health Organisation, one million years of healthy life are lost in Western Europe every year due to exposure to environmental noise. In order to evaluate and manage environmental noise in the European Union, Directive END 2002/49/EC requires Member States to prepare and publish updated noise maps and relative action plans every five years. This includes agglomerations of more than 100,000 inhabitants and major roads, train tracks and airports. Thanks to recent technological advances, the noise map creation paradigm has changed substantially, allowing noise level measurements to be automated using wireless acoustic sensor networks for real-time noise map generation. However, these networks cannot prevent a series of situations that would bias the actual measurement of sound equivalent levels, causing the map not to be true to the reality perceived by the citizen, e.g., the sound of birds, the industry, the claxons, the mermaids, conversations that occur near sensors or weather phenomena such as rain and wind. This thesis studies the characterization of acoustic events for the tailoring of dynamic traffic noise maps. The study begins by presenting the context of the thesis, the LIFE DYNAMAP project, which aims to measure traffic noise levels in two pilot areas and dynamically integrate them into a noise map that is updated in real time. After that, a detailed analysis is presented for the events in the two areas, urban and suburban, and various characterizations are applied. One of the presented measures is the impact on the equivalent sound level (Leq), which allows the measurement of bias resulting from the presence of certain acoustic events in the making of traffic noise maps. The use of perceptual tests using psychoacoustic metrics is also considered in order to adapt the characterization of these events to citizen perception. The main purpose of the thesis is to characterize the events of urban and suburban environments to offer noise maps more faithful to the reality perceived by the citizen in relation to the sound environment where it is found. And during the thesis, the importance of sound detection on a network of acoustic sensors is shown in order to prevent measurement errors at equivalent levels and the need to train the detection system with data obtained from the same sensors on the network

On the Impact of Anomalous Noise Events on Road Traffic Noise Mapping in Urban and Suburban Environments

Noise pollution is a critical factor affecting public health, the relationship between road traffic noise (RTN) and several diseases in urban areas being especially disturbing. The Environmental Noise Directive 2002/49/EC and the CNOSSOS-EU framework are the main instruments of the European Union to identify and combat noise pollution, requiring Member States to compose and publish noise maps and noise management action plans every five years. Nowadays, the noise maps are starting to be tailored by means of Wireless Acoustic Sensor Networks (WASN). In order to exclusively monitor the impact of RTN on the well-being of citizens through WASN-based approaches, those noise sources unrelated to RTN denoted as Anomalous Noise Events (ANEs) should be removed from the noise map generation. This paper introduces an analysis methodology considering both Signal-to-Noise Ratio (SNR) and duration of ANEs to evaluate their impact on the A-weighted equivalent RTN level calculation for different integration times. The experiments conducted on 9 h of real-life data from the WASN-based DYNAMAP project show that both individual high-impact events and aggregated medium-impact events bias significantly the equivalent noise levels of the RTN map, making any derived study about public health impact inaccurate

Impact of Individual Anomalous Noise Events on the Monitoring of Traffic Noise in Urban Areas

At least one million healthy life years are lost every year from traffic-related noise in the western part of Europe according to the World Health Organization. Other diseases have been linked with environmental noise, such as sleep disturbance, heart illnesses or tinnitus. The Environmental Noise Directive 2002/49/EC (END) and the CNOSSOS-EU framework are the main instruments provided by the European Union (EU) to identify and combat the noise pollution in the European countries. The END asks the EU member states to publish noise maps and the consequent action plans every five years. In order to automatize the process of noise monitoring, several projects are aimed at implementing a noise-mapping system by means of a wireless acoustic sensor network. However, to analyze the impact of traffic noise on public health, noise events non-related to traffic should be removed from the noise map computation since they may bias significantly the result. This work evaluates the impact of individual anomalous noise events on the equivalent sound level computation in relation to their Signal-to-Noise Ratio (SNR) and duration. The analysis is conducted within the framework of the LIFE DYNAMAP project, which is aimed at representing the acoustic impact of road infrastructures through dynamic noise mapping. The experiments consider four hours of real-life acoustic data recorded in the urban area of Milan (Italy), defining as critical those anomalous noise events exceeding the A-weighted equivalent sound level computation by more than 2 dB in a 5-min integration time. The results evidence, on the one hand, the presence of critical anomalous noise events, and on the other hand, prove that both SNR and duration are relevant parameters to characterize these events, which should be removed to avoid biasing subsequent health studies or action plans

Interannual Variation of a 12,760 km Transequatorial Ionospheric Channel Availability and Its Dependence on Ionization

The ionosphere provides a channel able for long-haul and Non-Line-Of-Sight (NLOS) communications. Nonetheless, the amount of ionization depends on the Sun activity, whose diurnal and seasonal cycles transform the channel constantly. La Salle and the Observatori de l’Ebre have been sounding a 12,760 km ionospheric channel from Antarctica (62.7°S, 299.6°E) to Spain (41.0°N, 1.0°E) in order to find this evidence and to analyze the characteristics of this particular channel. The final goal of the project is to establish a stable communications link to be used as backup or for low rate data transmission. The aim of this paper is to prove the relation between the channel availability and the Sun phenomena affecting the ionization in four consecutive sounding campaigns

Acoustic Categorization of the urban Multi-Sensor Network ofthe DYNAMAP LIFE project developed for Road Traffic NoiseMapping

The DYNAMAP LIFE project proposes the implementation of a dynamic noisemapping system able to determine the acoustic impact of road infrastructures inreal-time, following the European Noise Directive 2002/49/EC. A Multi-SensorNetwork collects the noise level measurements in two pilot areas: in the cityof Milan and in the A90 motorway around Rome. For a proper evaluation ofthe equivalent noise level of road infrastructures, the anomalous noise events(ANE) unrelated to traffic noise (e.g. sirens, horns, speech, doors. . . ) should beremoved automatically.For this purpose, an anomalous noise events detector(ANED) has been designed using Mel-Frequency Cepstral Coefficients (MFCC)and Gaussian Mixture Models (GMM). This work focuses on the analysis of thespectral characteristics of the acoustic data from the 24-nodes of the Milan urbanarea network in order to determine whether a single adjustment of the ANED cancope with the particularities of each sensor location. To that effect, representativeacoustic data has been collected through the Multi-Sensor network in real-operationconditions. These data have been subsequently analyzed in terms of their spectro-temporal distribution as a first step of the generalization of the ANED algorithm forall the nodes in the WASN

Performance Analysis of the Acoustic Event Detector in the DYNAMAP’s Rome suburban area

Environmental noise is increasing year after year and, besides annoyance, it causes harmful health effects on people according to last 2018 WHO report. The Environmental Noise Directive 2002/49/EC (END) is the main instrument of the European Union to identify and combat noise pollution, followed by the CNOSSOS-EU methodological framework. In order to apply the END legislation, the EU Member States have to publish noise maps and action plans every five years. The use of Wireless Acoustic Sensor Networks (WASNs) changes the paradigm that addresses the END regulatory requirements as they enable the dynamic ubiquitous measurement of environmental noise pollution. Following the END, the DYNAMAP project develops a WASN-based lowcost noise mapping system to monitor in real-time the impact of road infrastructures in two pilot areas: Milan and Rome. To avoid biasing the noise maps with noise levels unrelated to traffic noise, an Anomalous Noise Event Detector (ANED) is included to remove them from the corresponding LAeq. The paper reflects the adaptation of the ANED algorithm to the WASN of the suburban area of Rome, which requires a specific analysis of the particularities of the suburban audio database, as well as future challenges and research on the generalization of the WASN

Detection of Anomalous Noise Events for Real-Time Road-Traffic Noise Mapping: The Dynamap's project case study

Environmental noise is increasing year after year, especially in urban and suburban areas. Besides annoyance, environmental noise also causes harmful health effects on people. The Environmental Noise Directive 2002/49/EC (END) is the main instrument of the European Union to identify and combat noise pollution, followed by the CNOSSOS-EU methodological framework. In compliance with the END legislation, the European Member States are required to publish noise maps and action plans every five years. The emergence of Wireless Acoustic Sensor Networks (WASNs) have changed the paradigm to address the END regulatory requirements, allowing the dynamic ubiquitous measurement of environmental noise pollution. Following the END, the LIFE DYNAMAP project aims to develop a WASN-based low-cost noise mapping system to monitor the acoustic impact of road infrastructures in real time. Those acoustic events unrelated to regular traffic noise should be removed from the equivalent noise level calculations to avoid biasing the noise map generation. This work describes the different approaches developed within the DYNAMAP project to implement an Anomalous Noise Event Detector on the low-cost sensors of the network, considering both synthetic and real-life acoustic data.Moreover, the paper reflects on several open challenges, discussing how to tackle them for the future deployment of WASN-based noise monitoring systems in real-life operating conditions

Detection of Anomalous Noise Events on Low-Capacity Acoustic Nodes for Dynamic Road Traffic Noise Mapping within an Hybrid WASN

One of the main aspects affecting the quality of life of people living in urban and suburban areas is the continuous exposure to high road traffic noise (RTN) levels. Nowadays, thanks to Wireless Acoustic Sensor Networks (WASN) noise in Smart Cities has started to be automatically mapped. To obtain a reliable picture of the RTN, those anomalous noise events (ANE) unrelated to road traffic (sirens, horns, people, etc.) should be removed from the noise map computation by means of an Anomalous Noise Event Detector (ANED). In Hybrid WASNs, with master-slave architecture, ANED should be implemented in both high-capacity (Hi-Cap) and low-capacity (Lo-Cap) sensors, following the same principle to obtain consistent results. This work presents an ANED version to run in real-time on μ Controller-based Lo-Cap sensors of a hybrid WASN, discriminating RTN from ANE through their Mel-based spectral energy differences. The experiments, considering 9 h and 8 min of real-life acoustic data from both urban and suburban environments, show the feasibility of the proposal both in terms of computational load and in classification accuracy. Specifically, the ANED Lo-Cap requires around 16/ of the computational load of the ANED Hi-Cap, while classification accuracies are slightly lower (around 10%). However, preliminary analyses show that these results could be improved in around 4% in the future by means of considering optimal frequency selection

Aggregate Impact of Anomalous Noise Events on the WASN-Based Computation of Road Traffic Noise Levels in Urban and Suburban Environments

Environmental noise can be defined as the accumulation of noise pollution caused by sounds generated by outdoor human activities, Road Traffic Noise (RTN) being the main source in urban and suburban areas. To address the negative effects of environmental noise on public health, the European Environmental Noise Directive requires EU member states to tailor noise maps and define the corresponding action plans every five years for major agglomerations and key infrastructures. Noise maps have been hitherto created from expert-based measurements, after cleaning the recorded acoustic data of undesired acoustic events, or Anomalous Noise Events (ANEs). In recent years, Wireless Acoustic Sensor Networks (WASNs) have become an alternative. However, most of the proposals focus on measuring global noise levels without taking into account the presence of ANEs. The LIFE DYNAMAP project has developed a WASN-based dynamic noise mapping system to analyze the acoustic impact of road infrastructures in real time based solely on RTN levels. After studying the bias caused by individual ANEs on the computation of the A-weighted equivalent noise levels through an expert-based dataset obtained before installing the sensor networks, this work evaluates the aggregate impact of the ANEs on the RTN measurements in a real-operation environment. To that effect, 304 h and 20 min of labeled acoustic data collected through the two WASNs deployed in both pilot areas have been analyzed, computing the individual and aggregate impacts of ANEs for each sensor location and impact range (low, medium and high) for a 5 min integration time. The study shows the regular occurrence of ANEs when monitoring RTN levels in both acoustic environments, which are especially common in the urban area. Moreover, the results reveal that the aggregate contribution of low- and medium-impact ANEs can become as critical as the presence of high-impact individual ANEs, thus highlighting the importance of their automatic removal to obtain reliable WASN-based RTN maps in real-operation environments

Adapting an Anomalous Noise Events Detectorfor Real-Life Operation in the Rome SuburbanPilot Area of the DYNAMAP’s Project

The DYNAMAP project is aimed at implementing a dynamic noise mapping system able to determine the acoustic impact of road infrastructures in real-time, encouraged by the European Noise Directive 2002/49/EC. The noise maps are updated using the information retrieved from a low-cost Wireless Acoustic Sensor Network (WASN) deployed in two pilot areas: in the city of Milan (urban) and in the A90 motorway around Rome (suburban). For a proper evaluation of the road infrastructure noise level, the anomalous noise events (ANE) unrelated to traffic noise (e.g. sirens, horns, speech, doors,...) should be removed before updating the noise maps. To that effect, an anomalous noise events detector (ANED) has been designed and trained using data from a real-life recording campaign. In this work, the preliminary version of the ANED algorithm designed for Hi-Cap sensors of the network, and its performance is evaluated and adjusted to conform to the requirements of the final 19-node WASN deployed in the suburban environment. The study is focused on the use of acoustic data in real-life operating conditions and the degree of adaptation of the ANED algorithm for each and every sensor of the WASN deployed in the A90 motorway surrounding Rome. To that end, a two-phase process was conducted: firstly, an study of the preliminary ANED version when running with the operative data from the WASN; and secondly, the production of a new labelled audio dataset of 107 hours that reflects more accurately the real-life WASN conditions were the ANED will operate