scholarly journals A Digital Signal Processor Based Acoustic Sensor for Outdoor Noise Monitoring in Smart Cities

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 605 ◽  
Author(s):  
Juan Manuel López ◽  
Jesús Alonso ◽  
César Asensio ◽  
Ignacio Pavón ◽  
Luis Gascó ◽  
...  
Keyword(s):  
Acoustic Noise ◽  
Smart Cities ◽  
Monitoring Network ◽  
Noise Pollution ◽  
Sound Level ◽  
Noise Measurement ◽  
Acoustic Sensor ◽  
Measurement Instruments ◽  
Frequency Weighting

Presently, large cities have significant problems with noise pollution due to human activity. Transportation, economic activities, and leisure activities have an important impact on noise pollution. Acoustic noise monitoring must be done with equipment of high quality. Thus, long-term noise monitoring is a high-cost activity for administrations. For this reason, new alternative technological solutions are being used to reduce the costs of measurement instruments. This article presents a design for a versatile electronic device to measure outdoor noise. This device has been designed according to the technical standards for this type of instrument, which impose strict requirements on both the design and the quality of the device’s measurements. This instrument has been designed under the original equipment manufacturer (OEM) concept, so the microphone–electronics set can be used as a sensor that can be connected to any microprocessor-based device, and therefore can be easily attached to a monitoring network. To validate the instrument’s design, the device has been tested following the regulations of the calibration laboratories for sound level meters (SLM). These tests allowed us to evaluate the behavior of the electronics and the microphone, obtaining different results for these two elements. The results show that the electronics and algorithms implemented fully fit within the requirements of type 1 noise measurement instruments. However, the use of an electret microphone reduces the technical features of the designed instrument, which can only fully fit the requirements of type 2 noise measurement instruments. This situation shows that the microphone is a key element in this kind of instrument and an important element in the overall price. To test the instrument’s quality and show how it can be used for monitoring noise in smart wireless acoustic sensor networks, the designed equipment was connected to a commercial microprocessor board and inserted into the infrastructure of an existing outdoor monitoring network. This allowed us to deploy a low-cost sub-network in the city of Málaga (Spain) to analyze the noise of conflict areas due to high levels of leisure noise. The results obtained with this equipment are also shown. It has been verified that this equipment meets the similar requirements to those obtained for type 2 instruments for measuring outdoor noise. The designed equipment is a two-channel instrument, that simultaneously measures, in real time, 86 sound noise parameters for each channel, such as the equivalent continuous sound level (Leq) (with Z, C, and A frequency weighting), the peak level (with Z, C, and A frequency weighting), the maximum and minimum levels (with Z, C, and A frequency weighting), and the impulse, fast, and slow time weighting; seven percentiles (1%, 5%, 10%, 50%, 90%, 95%, and 99%); as well as continuous equivalent sound pressure levels in the one-third octave and octave frequency bands.

scholarly journals Wireless Acoustic Sensor Nodes for Noise Monitoring in the City of Linares (Jaén)

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 124 ◽  
Author(s):  
Jose-Angel Fernandez-Prieto ◽  
Joaquín Cañada-Bago ◽  
Manuel-Angel Gadeo-Martos
Keyword(s):  
Complete System ◽  
Smart Cities ◽  
Real Data ◽  
Sound Level ◽  
Topology Design ◽  
Sensor Nodes ◽  
Acoustic Sensor ◽  
Noise Levels ◽  
Starting Point ◽  
The City

Noise pollution is a problem that affects millions of people worldwide. Over the last few years, many researchers have devoted their attention to the design of wireless acoustic sensor networks (WASNs) to monitor the real data of continuous and precise noise levels and to create noise maps in real time and space. Although WASNs are becoming a reality in smart cities, some research studies argue that very few projects have been deployed around the world, with most of them deployed as pilots for only days or weeks, with a small number of nodes. In this paper, we describe the design and implementation of a complete system for a WASN deployed in the city of Linares (Jaén), Spain, which has been running continuously for ten months. The complete system covers the network topology design, hardware and software of the sensor nodes, protocols, and a private cloud web server platform. As a result, the information provided by the system for each location where the sensor nodes are deployed is as follows: LAeq for a given period of time; noise indicators Lden, Lday, Levening, and Lnight; percentile noise levels (LA01T, LA10T, LA50T, LA90T, and LA99T); a temporal evolution representation of noise levels; and the predominant frequency of the noise. Some comparisons have been made between the noise indicators calculated by the sensor nodes and those from a commercial sound level meter. The results suggest that the proposed system is perfectly suitable for use as a starting point to obtain accurate maps of the noise levels in smart cities.

scholarly journals Spatial characterization of noise levels at the Federal University of Agriculture, Abeokuta, Nigeria

2020 ◽  
Vol 4 (2) ◽  
pp. 323-340
Author(s):  
J. A. Oyedepo ◽  
D. M. Omoniyi ◽  
D. E. Oluyege ◽  
E. I. Babajide
Keyword(s):  
Noise Pollution ◽  
Sound Level ◽  
Noise Measurement ◽  
World Health ◽  
Residential Areas ◽  
Noise Levels ◽  
Noise Emission ◽  
Positioning Systems ◽  
Pollution Levels ◽  
The University

The study investigated the spatial variability in the distribution of noise pollution in Federal University of Agriculture, Abeokuta. Measurements of noise were taken from 10 locations on campus namely; the academic environment including the University library and college lecture auditoria, the residential areas comprising the Student hostels and Vice-chancellor’s lodge as well as other populated areas like the car park and student union building. The noise measurement was done in the morning and evenings of Mondays, Wednesdays and Saturdays over a period of 3 weeks in July 2019. The noise measurement was done with the aid of Smart Sensor Digital Sound Level meter (Model: AR824). The sampling points were geo-located using a hand-held receiver for Global Positioning Systems (GPS). Questionnaires were administered to members of the University community (staff and students) to determine their respective perception of campus noise on academic activities. Data (noise and survey) were subjected to statistical analysis. Spatial analysis of the noise levels includes surface interpolation (Krigging) to determine the spatial pattern of noise across the campus, particularly, the most tranquil and most chaotic locations. The results show noise pollution levels reaching 74.3 (db) and 73.0 (db) during weekdays at some locations on campus. The noise emission level at some locations within the University exceeded the World Health Organization and Federal Ministry of Environment of Nigeria’s permissible level of 55 db for residential areas. Generally, it was observed that the ambient noise from heavy duty generating with the student chattering put noise level above 35(db) to 55(db) recommended for educational institutions. It can be inferred from statistical analyses and spatial interpolations of recorded noise levels, that noise levels of many areas in FUNAAB exceed the recommended 40 db required for an institution of higher learning. The study however finds that staff and students have adjusted to the noise on campus. Lecturers have resorted to the use of public address systems in large classes while students go to serene locations for better assimilation when studying. The study recommends reduction of point-source noises such as replacing the diesel generators with solar power. Signage should be displayed at sensitive areas such as library to reduce unnecessary noise.

Effect of No-load and Load Condition on Transformer Sound

2018 ◽  
pp. 11-15
Author(s):  
Dr. Hitesh Paghadar
Keyword(s):  
Experimental Study ◽  
Power Transformer ◽  
Load Condition ◽  
Noise Pollution ◽  
Sound Level ◽  
Measurement Scale ◽  
Dominant Factor ◽  
Public Attention ◽  
Level Measurement ◽  
Human Ear

Increasing environment noise pollution is a matter of great concern and of late has been attracting public attention. Sound produces the minute oscillatory changes in air pressure and is audible to the human ear when in the frequency range of 20Hz to 20 kHz. The chief sources of audible sound are the magnetic circuit of transformer which produces sound due to magnetostriction phenomenon, vibration of windings, tank and other structural parts, and the noise produced by cooling equipments. This paper presents the validation for sound level measurement scale, why A-weighted scale is accepted for sound level measurement, experimental study carried out on 10MVA Power Transformer. Also presents the outcomes of comparison between No-Load sound & Load sound level measurement, experimental study carried out on different transformer like - 10MVA, 50MVA, 100MVA Power Transformer, to define the dominant factor of transformer sound generation.

Testing of Sonic-Absorbent Panels’ Behavior in Open-Air Environment

2012 ◽  
Author(s):  
Petru A. Pop ◽  
Patricia A. Ungur ◽  
Liviu Lazar ◽  
Mircea Gordan ◽  
Florin M. Marcu
Keyword(s):  
High Frequency ◽  
Noise Pollution ◽  
Sound Level ◽  
Sound Level Meter ◽  
Data Logger ◽  
Public Buildings ◽  
Gypsum Plaster ◽  
Level Meter ◽  
And Control

One wildly used method to reduce and control the noise pollution in green city’s buildings is using sonic-absorbent panels. Their applications can be multiple, such as the insulation of buildings, acoustic barriers and fences along the highway or in front of supermarkets, hospitals and other public buildings. This paper presents a method for testing the behavior of sonic-absorbent panels in open-air environment. The work represents a carrying on of previous research about absorbent materials from gypsum family, tested in lab conditions. The experiment setup used a dynamic installation and as a sample a stand formed by six sonic-absorbent panels from special modeling alpha-gypsum plaster. This installation has been composed of two loudspeakers for emitting the sound at a well-defined frequency by the first laptop, the microphone for detecting and transmitting the signal to the second laptop for analyzing and processing the data. All operations were performed using MATLAB Programs, while a Data Logger Sound Level Meter type CENTER 332 was put on near the microphone to compare both results. The first experiment of acoustic stand has been realized by setting up the installation at a frequency from 50 Hz to 1250 Hz and altering the distance between loudspeakers and stand at 0.5m to 1m and 1.5m, respectively. The second experiment kept the same test’s conditions, while two and three layers of sonic-absorbent panels formed the stand, respectively, but at same distance from source of 0.5 m. In both tests, the results underlined the good sonic-absorbent properties of these panels, especially at medium and high frequency, which can recommend using the panels for multiple outside applications.

A crowdsensing platform for real-time monitoring and analysis of noise pollution in smart cities

2021 ◽  
pp. 100588
Author(s):  
Ivan Jezdović ◽  
Snežana Popović ◽  
Miloš Radenković ◽  
Aleksandra Labus ◽  
Zorica Bogdanović
Keyword(s):  
Real Time ◽  
Smart Cities ◽  
Noise Pollution ◽  
Real Time Monitoring

scholarly journals ACOUSTIC NOISE POLLUTION FROM MARINE INDUSTRIAL ACTIVITIES: EXPOSURE AND IMPACTS

2018 ◽  
pp. 148-161 ◽  
Author(s):  
Halit Kuşku ◽  
Murat Yiğit ◽  
Sebahattin Ergün ◽  
Ümüt Yiğit ◽  
Nic Taylor
Keyword(s):  
Acoustic Noise ◽  
Noise Pollution ◽  
Industrial Activities

scholarly journals Investigation of Noise Pollution Distribution in Different Parts of Yazd Textile Factories

2021 ◽  
Author(s):  
Mohammad Javad Zare Sakhvidi ◽  
Hamideh Bidel ◽  
Ahmad Ali Kheirandish
Keyword(s):  
Occupational Exposure ◽  
Sound Pressure Level ◽  
Textile Industry ◽  
Sound Pressure ◽  
Noise Pollution ◽  
Sound Level ◽  
Pressure Level ◽  
Cross Sectional ◽  
Sound Pressure Levels ◽  
Different Parts

 Background: Chronic occupational exposure to noise is an unavoidable reality in the country's textile industry and even other countries. The aim of this study was to compare the sound pressure level in different parts of the textile industry in Yazd and in different parts of the textile industry. Methods: This cross-sectional study was performed on 930 textile workers in Yazd. A questionnaire was used to obtain demographic information and how to use protective equipment. Then, to obtain the sound pressure level of each unit and device and to use the measurement principles, a calibrated sound level meter was used. Then the results were analyzed using SPSS Ver.29 software. Results: The participants in this study were 714 males and 216 females with a mean age of 35.27 and 33.63 years, respectively. Seven hundred fifty-six participants (81.29%) were exposed to sound pressure levels higher than 85 dB. Among the participants, only 18.39% of the people used a protective phone permanently. Except for factory E, with an average sound pressure level of 77.78 dB, the rest of the factories had an average sound pressure level higher than the occupational exposure limit. The sound measurement results of different devices show that the sound pressure levels above 90 dB are related to the parts of Dolatab, Ring, Kinetting (knitting), Chanel, Autoconer, Dolakni, Open End, MultiLakni, Tabandegi, Texture, and Poy. Conclusion: Based on the results of the present study, noise above 90 dB is considered as one of the main risk factors in most parts of the textile industry (spinning and weaving), which in the absence of engineering, managerial or individual controls on it causes hearing loss in becoming employees of this industry

scholarly journals Impacts of vehicle tire on slip resistance and sound pollution in asphalt pavements

2021 ◽  
Vol 2 (3) ◽  
pp. 16-21
Author(s):  
Saeed Abbassi
Keyword(s):  
Urban Areas ◽  
Noise Pollution ◽  
Sound Level ◽  
Asphalt Pavements ◽  
Fine Grained ◽  
Sensitive Areas ◽  
Slip Resistance ◽  
Materials Used ◽  
The Cost ◽  
Pavement Friction

Noise pollution caused by vehicle traffic is one of the major problems in urban areas with road expansion. Due to the increase in the cost of construction and installation of sound walls to deal with noise pollution, to deal with this problem should look for methods that do not have additional costs and operating costs. Improving the pavement texture is one of the most effective ways to reduce tire noise and pavement and reduce the asphalt surface’s sound. To evaluate the slip resistance of asphalt, the English pendulum test according to ASTM E303-74 standard was performed on wet parts of asphalt in wet conditions. This device is used to examine the fine texture of the pavement. The number of pavement friction with a negative coefficient of 0.1469 has an inverse ratio with the intensity of sound level increases the number of pavement friction aligned with the amount of sound level created decreases. On the other hand, the depth of pavement texture, which is determined as the size of pavement materials, with a coefficient of 0.2810, has a direct ratio with the amount of noise pollution, and the smaller the number of fine-grained materials used will increase the sound level. According to the results of the coefficients estimated from the equation, it can be concluded that the preparation of pavements with an amount of friction can reduce the amount of noise pollution emitted by the movement of vehicles, especially in urban areas and sensitive areas. Therefore, it is recommended that in acoustically sensitive areas, in preparing pavements, arrangements be made to use coarser materials and maintain proper pavement resistance. For this purpose, in this article, the pavement’s texture is examined in the amount of noise created due to the tire’s interaction and the pavement.

scholarly journals Assessments and Control of Anthropogenic Noise Pollution in Students’ Residential Areas in Ogbomoso

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
A. O. Ajayeoba
Keyword(s):  
Medical History ◽  
Undergraduate Students ◽  
Circuit Breaker ◽  
Noise Pollution ◽  
Sound Level ◽  
Anthropogenic Sources ◽  
Anthropogenic Noise ◽  
Residential Areas ◽  
Sound System ◽  
And Control

Increased rate of noise-associated risk factors such as speech interference and reduction in productivity, necessitated that control and regulation measures be put in place, to contain anthropogenic noise pollution in the students’ hostels. Therefore, this study assessed the various anthropogenic sources of noise pollution in students’ hostels and developed a Sound Level Monitor and Control (SLMC) device. 1250 undergraduate students across 5 students’ residential zones were sampled for demographics and investigations were conducted into respondents’ perceived medical history, identification of noise sources, and evaluation of hearing loss. Effects of noise levels were evaluated using 100 respondents’ rooms per zone following standard procedures, considering Sound-System-Only (SSO), Generators-Only (GO), and combination of Sound-System-and-Generator (SSG), loud-conversations, etc., as sources of noise. However, a noise control device incorporated with a circuit breaker was developed. The respondents were 51.2% male and 48.8% female, with 58% in the age range 18 – 27 years. The medical history showed that 1.2 and 6.4% had a hearing problem in short and long times, respectively, while 43.6% affirmed that SSO was a major noise pollution causal factor. SSO, GO, loud conversations, traffic, and grinding machines were identified as the prominent sources of anthropogenic induced noise. The minimum average SL result gave a value of 62.8400dB for both ventilated and unventilated rooms, which is 14% above 55dB threshold value recommended by the National Environmental Standards and Regulations Enforcement Agency. The developed SLMC device gave notification at the SL above 55dB for 15 seconds before disconnecting the sound system if not regulated.

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