Environmental Noise Measurements Research Articles

Identification of daily environmental noise patterns in two different urban sites in Santiago, Chile.

Environmental noise can cause auditory and non-auditory adverse effects. To identify daily environmental noise patterns in two urban sites of Metropolitan Santiago. Continuous measurements of environmental noise in two sites of Metropolitan Santiago were analyzed by means of hierarchical cluster analysis. One site was a main street with heavy traffic and the second was a street from a neighborhood with intense nocturnal activity. The first phase of analysis consisted of clustering noise profiles with similar shapes according to the average linkage method, with correlation as the similarity measure. The second phase grouped the profiles with similar shapes into sub-clusters that also had similar absolute noise levels, using the complete linkage method, with absolute distance as the similarity measure. Two noise patterns were identified for the first site, one for weekdays (Monday to Friday) and another for weekends (Saturday and Sunday). For the second site five different patterns were identified (Monday to Wednesday, Thursday, Friday, Saturday, and Sunday). Also different patterns appeared for summer compared to the rest of the year. The noise levels of both sites were high. The detected noise levels can be annoying, cause sleep disturbances and increase the risk for hypertension and cardiovascular diseases, among other effects.

Analysis of the measurement uncertainty and its effects on noise mapping validations

This paper addresses the use of noise measurements when noise mapping simulations are intended to be validated. For this, a discussion about the measurement uncertainty and how to include it in the process of validation is carried out. Then, the contribution provided by the geo-referencing error of a GPS and its impact in the uncertainty is assessed. This is achieved by means of environmental noise measurements, which are conducted based on the accuracy radius given by a standard GPS. Furthermore, an assessment of the approach is conducted by means of numerical simulations using the commercial package SoundPLAN. The results indicate that the uncertainty of noise measurements should be included as it restricts the validation threshold (usually assumed as ±3 dB). Furthermore, the error generated by the inaccuracy of the geo-referencing process increases the uncertainty of the measurements and, therefore, of the noise maps. Finally, a method to calculate a total uncertainty, which partially includes the contributions of the geo-referencing error is also proposed.

Wireless Sensor Networks for Noise Measurement and Acoustic Event Recognitions in Urban Environments.

Nowadays, urban noise emerges as a distinct threat to people’s physiological and psychological health. Previous works mainly focus on the measurement and mapping of the noise by using Wireless Acoustic Sensor Networks (WASNs) and further propose some methods that can effectively reduce the noise pollution in urban environments. In addition, the research on the combination of environmental noise measurement and acoustic events recognition are rapidly progressing. In a real-life application, there still exists the challenges on the hardware design with enough computational capacity, the reduction of data amount with a reasonable method, the acoustic recognition with CNNs, and the deployment for the long-term outdoor monitoring. In this paper, we develop a novel system that utilizes the WASNs to monitor the urban noise and recognize acoustic events with a high performance. Specifically, the proposed system mainly includes the following three stages: (1) We used multiple sensor nodes that are equipped with various hardware devices and performed with assorted signal processing methods to capture noise levels and audio data; (2) the Convolutional Neural Networks (CNNs) take such captured data as inputs and classify them into different labels such as car horn, shout, crash, explosion; (3) we design a monitoring platform to visualize noise maps, acoustic event information, and noise statistics. Most importantly, we consider how to design effective sensor nodes in terms of cost, data transmission, and outdoor deployment. Experimental results demonstrate that the proposed system can measure the urban noise and recognize acoustic events with a high performance in real-life scenarios.

Territory management based on the assessment of environmental noise in near areas to two medical centers on zone planning units 44 and 47 in Bogotá

Introduction:This article shows the evaluation of environmental noise around the medical centers located in the UPZ Americas and Kennedy Central - Bogotá, and the proposal of some actions related to the planning of the territory as a strategy for mitigation. Problem:The Kennedy town has presented high levels of environmental noise, which is a worrying aspect due to its correlation with the effects on people's health. Objective:This research was conducted for the purpose of compiling updated information on environmental noise in the Kennedy locality and evaluating regulatory compliance and identifing the phenomena to establish actions that lead to its mitigation. Methodology:The measurement process was guided under the guidelines of ISO 1996:1 and the parameters established in Res. 627/2006 of the Ministry of Environment. Results:The ambient noise levels exceed the maximum permissible limits (55 dB) on the different days and hours of measurement. It was also determined that this phenomenon is mainly related to high vehicular flow as well as formal and informal commercial activities around medical centers. Conclusion:There is no regulatory compliance in relation to environmental noise and the territorial plan established in the UPZ. The suggested actions are: use of parks to plant native trees that act as biological barriers, non-use of surrounding streets as secondary traffic roads and reorganization of trade activities. Originality:Updated environmental noise data was obtained around medical centers in Kennedy and problems of inappropriate growth and development were identified. Limitations:Lack of information on environmental noise measurements in other sectors of the area.

河南省新乡县小冀镇环境噪声的测量与分析

河南省新乡县小冀镇环境噪声的测量与分析

Microphone position and noise exposure assessment of building façades

The prevention or reduction of the exposure of the population to environmental noise is the fundamental objective of the European Noise Directive (END). To this end, strategic noise maps are considered as the basic tool and on-site measurements play an important role in its successful implementation. In this regard, the ISO 1996 standards are the reference for the measurement and assessment of environmental noise, but their application may be complex in many cases. It is therefore necessary to find urban scenarios in which the effects of the placement of the measuring equipment with respect to the façade on noise exposure levels can be analysed.In this study, an educational building was selected for an analysis of the differences in the weekly sound level from road traffic between a microphone flush-mounted on a plate at the façade and another placed between 0.5 and 2.0 m from it. The recommendations in Annex B of ISO 1996-2 were followed in the placement of the microphones. A broadband analysis shows that similar results were found for the four distances analysed, but that variations of up to 0.6 dBA above the reference value arose. An analogous study using frequency octave bands shows differences higher than 2 dB between the measured configurations for bands under 250 Hz. Based on the distance range given in ISO 1996-2 for the position of a microphone in front of a reflecting surface, the results suggest that the most appropriate option for accurately assessing the sound level incident on the façade of buildings is to place the microphone at a distance of 2 m if the guidelines of the ISO 1996-2 standard can be met.

Medición de Ruido en Estaciones Transformadoras - Experiencias para el desarrollo de un Procedimiento

El artículo que se presenta a continuación corresponde a los avances realizados en el marco del PID UTN 4436: "Ruido Audible En Estaciones Transformadoras", tomando como vía de trabajo la medición de ruido ambiental en estaciones transformadoras plenamente operativas a fin de desarrollar un procedimiento repetible y confiable, adecuado a lo exigido en la legislación vigente Res. SE N°77/1998, utilizando como sustento la Norma IRAM 4113, suplementaria de la Norma IRAM 4062, por razones que se presentarán más adelante.
 Como antecedente, el LAMCEM (Laboratorio Ambulante de Medición de Campo Eléctrico y Magnético), viene desarrollando actividades in situ desde el año 2000, aproximadamente, conociendo problemáticas propias de las mediciones de campo. En varias ocasiones su normal desarrollo, se ve condicionado por cuestiones aleatorias como, por ejemplo, seguridad referente al riesgo eléctrico en sistemas de potencia, condiciones atmosféricas, o características del entorno y circunstanciales. En el caso de aplicación del presente artículo, se describen algunas de ellas. Los datos tomados ex profeso para el proyecto se trabajaron en laboratorio para incorporar o descartar perspectivas al procedimiento propuesto.

Interlaboratory comparisons’ measurement uncertainty in the field of environmental noise

This paper deals with the problem of measurement uncertainty in acoustic measurements regarding the results of interlaboratory comparison (ILC). The measurement results of ILC in the field of environmental noise have been analysed taking into account the proposed methods for standard deviations’ calculation in repeatability and reproducibility conditions. In the field of environmental noise measurements of point sound source, the measurement results as well as the precision and accuracy are discussed bearing in mind the microphone positions. The results for expanded measurement uncertainty calculations are obtained following the ISO 1996-2:2007 and ISO 1996-2017 Standard. The obtained results showed that expanded measurement uncertainty from interlaboratory comparison results calculated from probability density functions is considerably less when compared with the procedure in Standards. A good agreement is gained for the difference between A-weighted level and spectral values from logarithmically averaged measurement results on the reflection surface and close to the reflection surface.

A low-cost noise measurement device for noise mapping based on mobile sampling

For the production of representative noise maps, a large amount of information is necessary, which includes, among others, on-site measurements of environmental noise. Thus, mobile sampling emerges as a possible solution for the enhancement of data acquisition. The present paper proposes a low-cost noise monitoring device, in order to take georeferenced mobile measurements at each 1/3 octave band (63 Hz–10 kHz). The implementation and accuracy tests of the equipment are presented. It is found, under laboratory and field tests, that the device measurement values are around ±0.5 dB of those obtained with a Class 1 sound level meter for LAeq and around ±1 dB for 1/3 octave band. Furthermore, a set of mobile measurements taken suggest that it is actually possible to perform the mobile sampling, which would improve the spatiotemporal granularity of noise measurements without compromising the accuracy, although certain requirements should be fulfilled to ensure representativeness.

Noise measurement across different land-use patterns

Introduction: In the current scenario, with noise exposure having serious effects on the well-being of an individual, it becomes necessary to monitor the noise levels in the environment and keep them under the permissible limits. The present research was aimed to measure and compare noise levels in different land-use patterns and also to identify a minimum duration required to obtain a stabilized LAeq values in environmental noise measurement. Methods: Noise measurements were carried out across residential, commercial, sensitive, and mixed land-use patterns during morning and afternoon time frames. The obtained results were represented using isopleth noise maps. Results: It was noted that noise levels exceeded the prescribed limits in all the four land-use categories. The greatest level of noise was noted in commercial areas followed by mixed, sensitive, and residential land-use types. Significant variations in LAeq values were noted only up to 10 min of noise measurement, and measured noise levels were stabilized beyond 10-min time mark in all the land-use categories. Conclusion: The higher noise levels recorded in the city would bring about adverse health effects on city dwellers in the long run, thus calling for strict law enforcement related to monitoring of noise levels and keeping them in check.

Environmental noise levels in hospital settings: A rapid review of measurement techniques and implementation in hospital settings.

Background:Hospitals provide treatment to improve patient health and well-being but the characteristics of the care environment receive little attention. Excessive noise at night has a negative impact on in-patient health through disturbed sleep. To address this hospital staff must measure night-time environmental noise levels. Therefore, an understanding of environmental noise measurement techniques is required. In this review, we aim to 1) provide a technical overview of factors to consider when measuring environmental noise in hospital settings; 2) conduct a rapid review on the equipment and approaches used to objectively measured noise in hospitals and identify methodological limitations.Design:A rapid review of original research articles, from three databases, published since 2008. Studies were included if noise levels were objectively measured in a hospital setting where patients were receiving treatment.Results:1429 articles were identified with 76 included in the review. There was significant variability in the approaches used to measure environmental noise in hospitals. Only 14.5% of studies contained sufficient information to support replication of the measurement process. Most studies measured noise levels using a sound level meter positioned closed to a patient’s bed area in an intensive care unit.Conclusion:Unwanted environmental noise in hospital setting impacts negatively on patient and staff health and well-being. However, this literature review found that the approaches used to objectively measure noise level in hospital settings have been inconsistent and poorly reported. Recommendations on best-practice methods to measure noise levels in hospital environments are provided.

A GIS – based method for assessment and mapping of noise pollution in Ota metropolis, Nigeria

A detailed method used for assessing and mapping noise pollution levels in Ota metropolis, Nigeria using ArcGIS 10.5 Software is presented in this paper. Noise readings were measured at a time interval of 30 min for each site considered using a precision grade sound level meter. The noise map developed was based on the computed values of average equivalent noise (LAeq) for the selected locations. Results of this study show that the A weighted sound level (LAeq), the background noise level (L10) and the peak noise level (L90) vary with location and period of the day due to traffic characteristics especially traffic volume, vehicle horns, vehicle mounted speakers, and unmuffled vehicles at road Junctions, major roads, motor parks and commercial centres. Based on the U.S. Department of Housing and Urban Development (HUD) recommendations and standards, only one (1) out of the 41 locations considered is under normally acceptable situation, while 12 locations are under normally unacceptable and the noise levels of the rest locations are clearly unacceptable. Results of this study are useful as reference and guideline for future planning and regulations on noise limit to be implemented for urban areas like Ota Metropolis.•Instrumentation used in this study for the environmental noise measurements consisted of a precision-grade sound-level meter – Model 8922 RS232.•The Geographical Positioning System (GPS) device (model: Magellan eXplorist 310) was used to obtain the exact coordinates of each location where noise level readings were recorded.•ArcGIS 10.5 software was used in this study to develop noise map for Ota Metropolis.

An averaging method for accurately calibrating smartphone microphones for environmental noise measurement

Smartphones have become ubiquitous not only as communication devices but also as smart devices for majority of the population. The small form-factor of smartphones together with a rich set of application programming interfaces, low-power consumption, and presence of several types of sensors such as GPS, microphone, gyroscope, accelerometer, barometer etc. makes them a good candidate for building apps for measuring and monitoring various environmental parameters. However, for these apps to be useful the sensors must be first calibrated. In this paper, we focus on methodologies for accurately measuring sound pressure level and frequency spectrum using microphone built into smartphones. For this purpose, we present an averaging method for accurately calibrating a typical smartphone microphone against a reference microphone. We show experimental results illustrating that the proposed method can achieve an accuracy of ±0.7 dB for 99.7% of measurements for three Samsung smartphones. We also present results showing that it is possible to calibrate a smartphone using another smartphone calibrated using our method.

Microphone array based automated environmental noise measurement system

State of the art environmental noise monitoring systems are based on digital signal processing. In general, they measure and store environmental noise levels, but also perform computation, spectral filtering, narrowband spectral analysis, evaluation of statistical indices, wave recordings, detection of noise events based on thresholds, and other similar tasks. Advances in processing power enabled application of smartphones for environmental noise measurements as well as the development of more sophisticated equipment capable of complex multichannel digital signal processing in real time. This paper describes the development of three new measurement methods and their application in environmental noise monitoring system: 1) an automatic exclusion of uncorrelated noise events from measurements, 2) an automatic identification of the dominant noise source direction and 3) an automatic classification of the observed noise event. The implementation of these three options can reduce the need for human resources, ensuring lower costs and more reliable measurement results. Immision directivity is defined to determine the dominance of the noise source compared to the background noise. The suggested technical solution and new procedure was practically applied as a part of autonomous measurement and noise source classification system in the ambient noise investigation in a residential area.

From Standard Specifications to LAeq Uncertainty in Environmental Noise Measurements

From Standard Specifications to<i> L</i>_Aeq Uncertainty in Environmental Noise Measurements

Annoyance Judgment and Measurements of Environmental Noise: A Focus on Italian Secondary Schools.

The effects of noise on students’ health, well-being, and learning are of growing concern among both the general public and policy-makers in Europe. Several studies have highlighted the consequences of noise on children’s learning and performance at school. This study investigates the relationship between noise judgment in school goers aged 11–18 and noise measurements aimed at evaluating their exposure at school. For this purpose, a questionnaire was administered to 521 individuals in 28 classrooms in eight schools of four cities in Italy, with different environmental characteristics. Using a Likert-type scale, a selected set of responses related to noise generated an Annoyance Index (AI) score for each student and a classroom median score (MAI). From the noise data acquired, a global noise score (GNS) was assigned to each classroom. A higher AI was found in industrialized areas and among younger students. No significant differences in noise judgment were found by gender. A significant inverse correlation was described between MAI and GNS, thus the better the acoustic quality of the classrooms, the less the perceived noise and annoyance. The results show that noise perception and consequent disturbance are highly correlated with classroom acoustics, and confirm that annoyance represents the most widespread subjective response to noise.

NOISE MAPPING OF CELAL BAYAR BOULEVARD AND THE NOISE EXPOSURE ANALYSIS OF HIGHWAY NOISE SPECIFICALLY FOR EDUCATIONAL AND HEALTH BUILDINGS

This study was carried out to determine and evaluate the noise control analyses and noise mapping studies performed by the measurement and simulation program for the road traffic noise on Celal Bayar Boulevard in Ankara. Method: In this context, in the selected sample study area, a noise map was created using the CadnaA simulation program in the light of the data obtained through environmental noise measurements (Ldaytime, Levening, Lnight) and vehicle counts, and the measurement and simulation program results obtained were compared. Then, the facade measurements were performed in Gazi University Faculty of Engineering and Architecture Building, Ankara University Faculty of Medicine Deanship and Morphology Building and Hacettepe University Hospital Building specifically for educational and health buildings located on Celal Bayar Boulevard, and the facade analysis was performed using the CadnaA simulation program. Findings: In the study, according to the noise map data generated by the CadnaA simulation program, it was determined that there was an equivalent continuous sound pressure level (Leq) between 70.5 – 81.8 dBA during the daytime, between 64.6 – 76.9 dBA during the evening hours, between 58.6 – 71.7 dBA during the night hours, and between Lgag 69.8 – 81.7 dBA along Celal Bayar Boulevard. Conclusion: As a result of this study, it was observed that the noise maps and action plans planned to be revised with simulation programs every 5 years should be measured and supported.

Determining environmental noise measurement uncertainty in the context of the Italian legislative framework

Abstract This paper aims to demonstrate the importance of uncertainties in the measurement of environmental noise in the context of Italian legislation on noise pollution focusing the attention on the variability of the measurand as a source of uncertainty and offering a proposal for the evaluation of uncertainty for traffic noise measurement. In particular, drawing on a real traffic noise dataset, firstly outliers are eliminated from the actual noise measurements using an outlier detection algorithm based on K -neighbors distance and then uncertainty range is estimated with the bootstrap- t method. Since the original sequence was Gaussian, this range was compared with the confidence interval of the mean ± standard deviation interval and two intervals were almost coincident.

Noise Pollution Control System in the Hospital Environment

Problems related to environmental noise are not a new subject, but they became a major issue to solve because of the increasing, in complexity and intensity, of human activities due technological advances. Numerous international studies had dealt with the exposure of critical patients to noisy environment such as the Neonatal Intensive Care Units; their results show that there are difficulties in the organization in the developing brain, it can damage the delicate auditory structures and can cause biorhythm disorders, specially in preterm infants. The objective of this paper is to present the development and implementation of a control system that includes technical-management-training aspects to regulate the levels of specific noise sources in the neonatal hospitalization environment. For this purpose, there were applied different tools like: observations, surveys, procedures, an electronic control device and a training program for a Neonatal Service Unit. As a result, all noise sources were identified -some of them are eliminable-; all the service stable staff categories participated voluntarily; environmental noise measurements yielded values between 62.5 and 64.6 dBA and maximum were between 86.1 and 89.7 dBA; it was designed and installed a noise control device and the staff is being trained in noise reduction best practices.

Differences Between Road Traffic and Leisure Noise in Urban Areas. Developing a Model for Automatic Identification

Leisure and road traffic are two of the major contributors to environmental noise in urban agglomerations. This environmental problem is particularly important in some cities, where there is a massive circulation of traffic vehicles and numerous outdoor social activities with a leisure noise mainly composed by human-related sounds. Due to the apparent differences between human-related sounds and road traffic sounds, the descriptors used to approach a proper evaluation of leisure noise may not be the same as the ones used for road traffic noise evaluation. This paper is aimed at analyzing the road traffic and leisure noise characteristics and the most important parameters to study and evaluate both noise sources. Therefore, as usually both noise sources are mixed, a model has been developed and tested which, when provided an environmental noise measurement, will be able to identify what kind of noise (leisure or road traffic noise) is dominant in a given environment. This model, done by using Support Vector Machines (SVMs) and Regression Analysis algorithms, allows focusing the abatement actions towards the noise source identified as dominant, and thus, addressing a better management and a proper control of the environmental noise in urban environments.