Monitoring Of Noise Levels Research Articles

IMPLEMENTATION OF ENVIRONMENTALLY FRIENDLY MEASURES AT TALLINN AIRPORT

This paper aims at studying the problems of aviation noise and air, soil and water pollution in Tallinn Airport and the implementation of measures to make the airport more environmentally friendly. At present Tallinn Airport has two stationary noise level monitoring terminals and one mobile terminal for metering and modelling the noise level caused by aircraft taking-off and landing. Research shows that Tallinn Airport has not yet exceeded the noise limits stipulated by regulations. The area surrounding Tallinn Airport has been divided into four noise zones. Zone 1, where the noise level does not exceed 55 dB, is suitable for a majority of types of buildings, whereas Zone 4, where the noise level exceeds 70 dB and the highest level measured was 105 dB, is absolutely unacceptable as a building area. In recent years the number of flights flying over the residential areas of Tallinn has been reduced significantly, i.e. the number of flights taking off from runway 26 and landing on runway 08. In suitable weather conditions, noisy aircraft are directed to land on RWY 26 and take off from RWY08. Thanks to the measures mentioned above, air pollution from aircraft exhaust gases has been reduced considerably in Tallinn. After the completion of the military airfield at Ämari in the nearest future, it is going to be possible to transfer the cargo flights, usually made by large noisy jets, from Tallinn Airport to Ämari. Various measures have also been taken to reduce the pollution of soil and water within the area of Tallinn Airport.

Noise pollution monitoring during Diwali festival in Golden city Jaisalmer of Rajasthan, India

Noise is an important pollutant of environment causing various health hazards. In the present study, ambient noise levels were measured in two different areas within Jaisalmer city viz., commercial and residential area, on festive day and non-festive day (after) of Diwali. The results of noise level monitoring revealed the fact that due to higher amount of firecrackers on Diwali festival noise level was enhanced. The average equivalent noise level was increased from 61.94 dB to 72 dB (A) and 64.68 dB to 73.74 dB (A) on festive day, respectively, in selected residential and commercial areas, where noise was 30 and 13.44 % higher than standards of Central Pollution Control Board, New Delhi for residential and commercial areas, respectively.

Simultaneously monitoring noise and cetaceans in the Ligurian Sea

The interest in the effect of anthropogenic noise on marine life increasing rapidly, this is driven primarily by legislations in many countries that noise can be considered to be a pollutant, as for the European Marine Strategy Framework Directive. One particular area of concern has been in the interaction of military tactical sonar and the acoustically more sensitive species of cetacean, in particular the effect on beaked whales. Five ecological acoustics recorders (EAR) buoy having a sampling frequency of 80 kHz and a hydrophone with a flat sensitivity of -193.5 ± 1dB re 1 μPa up to 40 kHz have been deployed in the Northern Mediterranean at a depth of about 850 m in a canyon region known to host a population of Cuvier beaked whales (Ziphius cavirostris). The area is also located in the nearby of different shipping harbors and ferries routes. The utility of the EAR systems is that they simultaneously allow monitoring of noise levels across a wide frequency range while simultaneously allowing assessment of the presence of a range of different species – including Cuvier beaked whale sperm whale and dolphins. Here we discuss the initial results for noise assessment and for cetacean monitoring.

Development of a computer-based automated pure tone hearing screening device: a preliminary clinical trial.

Hearing screening is important for the early detection of hearing loss. The requirements of specialized equipment, skilled personnel, and quiet environments for valid screening results limit its application in schools and health clinics. This study aimed to develop an automated hearing screening kit (auto-kit) with the capability of realtime noise level monitoring to ensure that the screening is performed in an environment that conforms to the standard. The auto-kit consists of a laptop, a 24-bit resolution sound card, headphones, a microphone, and a graphical user interface, which is calibrated according to the American National Standards Institute S3.6-2004 standard. The auto-kit can present four test tones (500, 1000, 2000, and 4000 Hz) at 25 or 40 dB HL screening cut-off level. The clinical results at 40 dB HL screening cut-off level showed that the auto-kit has a sensitivity of 92.5% and a specificity of 75.0%. Because the 500 Hz test tone is not included in the standard hearing screening procedure, it can be excluded from the auto-kit test procedure. The exclusion of 500 Hz test tone improved the specificity of the auto-kit from 75.0% to 92.3%, which suggests that the auto-kit could be a valid hearing screening device. In conclusion, the auto-kit may be a valuable hearing screening tool, especially in countries where resources are limited.

Noise Levels inside the Cabin of Heavy Earth Moving Machineries: Its Significance and Association

Systematic monitoring of noise levels was carried out inside the cabin of all the Heavy Earth Moving Machineries deployed in a chromite mining complex during summer 2008 and winter 2009. The present study aimed to estimate the significance and the degree of association of the noise levels with respect to all the HEMMs. The analysis (t-test) shows that the equivalent noise (Leq) levels inside the cabin differ significantly with the test value of 85 dBA for all the HEMMs. Analysis of Variance reveals that the values of Leq are not identical with respect to the time of monitoring and also inside the cabins of different HEMMs (p<0.01). The Leq is the most significant during third part of time monitoring inside the cabin of the dozer (p<0.01). The Chi-square test reveals that 0.752 is the highest degree of association between the dozer, p=0.000(p<0.01) and Leq levels and exists a high degree of association.

Sampling approaches to predict urban street noise levels using fixed and temporary microphones

Requirements for static (prediction of L(den) and diurnal averaged noise pattern) and dynamic (prediction of 15 min and 60 min evolution of L(Aeq) and statistical levels L(A90,)L(A50) and L(A10)) noise level monitoring are investigated in this paper. Noise levels are measured for 72 consecutive days at 5 neighboring streets in an inner-city noise measurement network in Gent, Flanders, Belgium. We present a method to make predictions based on a fixed monitoring station, combined with short-term sampling at temporary stations. It is shown that relying on a fixed station improves the estimation of L(den) at other locations, and allows for the reduction of the number of samples needed and their duration; L(den) is estimated with an error that does not exceed 1.5 dB(A) to 3.4 dB(A) according to the location, for 90% of the 3 × 15 min samples. Also the diurnal averaged noise pattern can be estimated with a good accuracy in this way. It was shown that there is an optimal location for the fixed station which can be found by short-term measurements only. Short-term level predictions were shown to be more difficult; 7 day samples were needed to build models able to estimate the evolution of L(Aeq,60min) with a RMSE ranging between 1.4 dB(A) and 3.7 dB(A). These higher values can be explained by the very pronounced short-term variations appearing in typical streets, which are not correlated between locations. On the other hand, moderately accurate predictions can be achieved, even based on short-term sampling (a 3 × 15 minute sampling duration seems to be sufficient for many of the accuracy goals set related to static and dynamic monitoring). Finally, the method proposed also allows for the prediction of the evolution of statistical indicators.

Reduction of commercial aircraft noise emission around airports. A new environmental challenge

Abstract Noise abatement procedures (NAPs) are considered as a necessary measure for a balanced approach of noise control around airports. Their correct implementation depends upon many factors, which vary in operation and influence the efficiency of the NAPs. Any system, which defines the correct features of the NAPs for particular aircraft in specific conditions, would be useful for noise control. Thus, implementation of noise level monitoring systems, currently used around airports, gives a noise map in residential areas but cannot identify source frequencies and their impact on the environment. Consequently, this paper has been produced particularly to characterize the frequential aspect of aircraft noise emission. Its main objective is the analysis of the dominant frequencies emitted during approaches to the Lyon Saint-Exupéry International Airport (France) having a negative impact on the population living around this airport. Thus, the results obtained make it possible to show, through an empirical model of aircraft noise, the effectiveness of this experimental work.

Monitoring of noise reduction from traffic speed control

In November 2005, at the Hague, Amsterdam, Rotterdam and Utrecht, a 80 km/u speed limit was introduced on sections of motorways in the Netherlands. The aim was to evaluate the effects on noise, air quality and the circulation of the traffic. RIVM investigated the effects of noise emission by direct measurement at the sections with speed limit. This paper gives the results from continuous monitoring of noise levels that was started at July 2005 and continued up to November 2006. In the presentation the average measured effects on the equivalent noise emissions at the different sites will be given. Also the effects of traffic speed reduction on dwellings in the neighborhood of the motorways were evaluated using noise maps. Furthermore, apart from the average equivalent noise levels, the statistical noise indicators L5, L10, L70, and L95 were continuously monitored. It was found that speed reduction induces more reduction on maximum noise levels than on the average (equivalent) noise levels, probably due to a more steady and even distribution of traffic speeds.

Optimizing localization of noise monitoring stations for the purpose of inverse engineering applications

Long‐term environmental monitoring of noise levels can be done using autonomous measurement stations. Because of the high cost of monitoring systems and management of these stations, it is essential to identify how many of measuring localization points are really required. In cases related to complex noise generation schemes, when there are various noise sources, the differences between calculations and measurements can be difficult to estimate. Therefore, it is vital to find some most appropriate locations for measurement stations which would ensure obtaining an adequate number of measurement results to be employed in the reverse engineering. These measurements can be then utilized to update dynamic noise maps. Furthermore, predictive noise models may be developed accordingly to certain local requirements. This could result in a better accuracy of dynamic noise maps. The paper focuses on defining the proper choice of the measurement points localizations. The experiments described include a comparison between real‐life measurement results performed with the Multimedia Noise Monitoring System developed at the Multimedia Systems Department of the Gdansk University of Technology and the noise level prediction results. The optimization of the number and location of noise monitoring points with regard to the measurement accuracy is also discussed.

COMMERCIAL AIRCRAFT NOISE ASSESSMENT AT LYON SAINT-EXUPÉRY INTERNATIONAL AIRPORT. IN FLIGHT SOURCE FREQUENCY CHARACTERISATION

Simple noise level monitoring systems, which are currently used around airports to create a noise map in residential areas, are unable to identify source frequencies and their impact on the environment. This article presents the dominant frequencies during aircraft approaches at Lyon Saint-Exupéry International Airport (France) and analyzes the evidence of their impact on the environment. The results have the potential to contribute to the improvement of environmental quality around airports. They provide the emitted frequencies during the operations which can be treated by passive or active control systems.

Dynamics of traffic noise in a tropical city Varanasi and its abatement through vegetation

Noise level monitoring and its reduction with different width and height of vegetation belt were studied in the Varanasi city. Noise level monitoring of the Varanasi city revealed the fact that area category A (without vegetation) was highly polluted as compare to area category B (with vegetation) having less fluctuation of traffic load. Four plant species Putranjeva roxburghi, Cestrum nocturnum, Hibiscus rosasinensis and Murraya peniculata were tested for noise reduction study at different frequencies. Experiment revealed the fact that H. rosasinensis reduced noise highest at both low and high frequencies (100-500 Hz, 22 dB and 2.5-6.3 KHz 26 dB), followed by M. peniculata (100-500 Hz, 18 dB and 2.5-6.3 KHz 20 dB), P. roxburghi (100-500 Hz 15 dB and 2.5-6.3 KHz 17 dB) and C. nocturnum (100-500 Hz 9 dB and 2.5-6.3 KHz 14 dB). Significance of vegetation belt in noise reduction was established with multiple regression models.

Analytic, Simulation, and Empirical Evaluation of Delay/Fault-Tolerant Mobile Sensor Networks

The delay/fault-tolerant mobile sensor network (DFT-MSN) has been proposed for pervasive information gathering. DFT-MSN distinguishes itself from conventional sensor networks by several unique characteristics such as sensor mobility, loose connectivity, and delay/fault tolerability. This paper focuses on the performance evaluation of DFT-MSN. We first introduce a queuing model by using Jackson network theory. While the queuing model is based on a few simplification assumptions for analytic tractability, it provides insights into the queuing behavior of the mobile sensors in DFT-MSN. Extensive simulations are performed under realistic environment and assumptions. Our simulation results show that the dynamic DFT-MSN data delivery scheme achieves the highest message delivery ratio with acceptable delay and transmission overhead, compared with simple schemes such as flooding and direct transmission or other approaches in the literature such as Zebranet. We have also implemented a DFT-MSN testbed by deploying crossbow motes for noise level monitoring in our university library. Though in a small scale, the testbed demonstrates the feasibility of DFT-MSN and provides guidance for future large scale deployment.

A study of ambient air quality and noise pollution in Nainital city

Nainital is a hill tourist place. It is famous for its natural beauty. Therefore, thousands of tourists from all over India and abroad come to visit this place. The environment of Nainital is fragile and sensitive, so it was intended to study the ambient air quality of the city. The present study includes the evaluation of ambient air quality and noise level. Ambient air monitoring has been conducted for suspended particulate matters, sulphur di-oxides and oxides of nitrogen at mall road (near Nagar Palika Library) and bus station (Tallital). The noise level monitoring was also conducted at different points of the city characterising commercial, residential area and silence zone. At other sites of silence zone, the values were usually beyond the prescribed limit. At all sites taken in commercial, areas, the values were beyond prescribed limit. The main sources of noise pollution in the city of Nainital is vehicular movements and the noise generated due to the use of horns of the vehicles. Similarly, the vehicular emissions are cause of air pollution. The SPM value at Nainital ranged from 88 to 366 mg/m3, sulphur dioxide remained in the range of 10.2 to 25mg/m3 and NO2 ranged between 13 and 86 mg/m3. The study revealed that the SPM and NO are beyond the limit prescribed for sensitive areas.

Exposure to noise inside transit buses in Kuwait: Measurements and passenger attitudes

Noise levels were measured, for the first time, inside 115 randomly selected transit buses, operating on 12 sample representative routes in Metropolitan Kuwait. Simultaneously with the monitoring of noise levels, the attitudes of 679 riders concerning the annoyance and long-term health impacts of noise were also surveyed. The noise and passenger attitude data were collected over 10 months (March - December 2000). The percentile distribution, equivalent noise level, traffic noise index and noise pollution levels inside four types of transit buses are presented. Riders' perceived annoyance and awareness of the long-term health impacts of noise were also determined and are discussed. The level of service and performance deficiencies of the public transit system in Kuwait, as perceived by its passengers, are also identified. A number of recommendations end the paper.

Automated monitoring of low level ambient noise levels

Automated monitoring of low level ambient noise levels presents many challenges. The obvious challenge is to have a noise monitor with a low noise floor, less than 20 dBA, so that the ambient can be monitored. Other challenges include designing a lightweight system that can be backpacked to the monitoring site, and the site selection. Site selection criteria include protecting the monitor from direct sunlight and heat, and locating the microphone so that the influence on the measurements from rustling leaves and wind will be minimal. This paper presents the results of our learning curve from three studies of low level ambient noise.

ICEBREAKER NOISE IN LANCASTER SOUND, N.W.T., CANADA: IMPLICATIONS FOR MARINE MAMMAL BEHAVIOR

Abstract: In 1986, we recorded the MV Arctic, CCGS des Groseilliers and MV Lady Franklin during routine icebreaking operations and travel to and from the mine at Nanisivik, Baffin Island, Northwest Territories, Canada. We found that the Arctic generated more high frequency noise than did the other vessels we recorded. Monitoring of vessel noise levels indicated that belugas and, probably, narwhals should be able to detect the high frequency components of Arctic noise at least as far as 25 to 30 km from the source. The ability of whales to detect the MV Arctic at long distances may explain why belugas and narwhals in Lancaster Sound seem to react to ships at longer distances than do other stocks of arctic whales.