Permissible Noise Levels Research Articles

Noise pollution in hospitals - A study of public perception.

Introduction:Hospitals are categorized under silent zone, but noise pollution in this setup is inevitable. The noise in hospitals may have adverse effects on the patients, caregivers and professionals working in hospitals.Aim:The aim of the study was to determine awareness of public regarding noise pollution in hospitals, its health effects and mitigation measures.Method:The present study was an internet-based questionnaire survey. The questionnaire consisted of a common Section-I for all participants and an additional Section-II for participants of the study who were Audiologists. Descriptive statistical analysis was done on the acquired data.Results:174 completed questionnaires were received and analysed, out of which 108 were general public and 66 were Audiologists. The data analysis revealed that the public is aware of the presence of noise in hospitals, some of its overt health effects and measures that can be taken to control the noise pollution in hospitals. Only 22.7% Audiologists who participated in the study were aware of the more technical aspects like permissible noise level in hospitals and their response was similar to that of the general public.Conclusion:Though the public is aware of some of the basic facts related to noise in hospitals, there is a need to create public awareness and to train Audiologists regarding hearing conservation program in hospital setups.

Assessment of Noise Level and Distribution from Socotherm Nigeria Limited: Its Health Implications on the Workers

Exposure to noise for a long period of time has been an issue of concern to occupational health workers. This study investigated noise pollution level (NPL) and its spatial distribution in Socotherm Nigeria Limited coating plants and its effects on the health of the workers. Six sampling points were selected on the grounds of intensity of activities. A digital sound level Metre-Extech 407730 was used to measure noise level at the sampling points namely, application area, welding spot, aggregate separator, generator/powerhouse, impingement plant, bushing area. A global positioning system (GPS)-NAVA 300 was used to record the GPS coordinates of the sampling noise hotspots in the factory. The Arc GIS software was used to interpolate the spatial distribution of noise within the factory for the working periods which include morning, afternoon and evening. With a wellconstructed questionnaire, results of the health implication of workers exposure to noise from the factory were recorded. Results revealed that afternoon has the highest noise level of 99.20 dB(A) at welding point and application area conveyor of the factory while the lowest noise was observed at 85.20 dB(A) which was at cold spot of chemical feed area of the factory. The study observed that majority of the machines (noise hotspots) produce noise that was above Occupational Safety and Health Association (OSHA) permissible noise level. This study therefore recommends that workers be encouraged to use personal protective equipment and be educated regarding noise induced hearing loss and other non-auditory effects of noise exposure. The factories should adopt and implement hearing conservation programs under the direction of an occupational and environmental health professional.

ENVIROMENTAL ASPECTS OF NOISE ASSESSMENT AND REGULATION IN THE DESIGN OF PORT COMPLEXES IN RUSSIA

A comparative analysis of various biological objects sensitivity to acoustic effects is being conducted. For many animal species, the frequency range at which sounds are heard is very different from that for humans and may not even intersect with it. The total frequency range at which various animals can hear covers at least eight orders of magnitude (from hundredths of Hz to hundreds of kHz), while for humans this interval is limited to only four orders of magnitude. Thus, the existing anthropocentric standards for permissible noise levels are unsuitable for regulating their impacts on natural ecosystems and it is necessary to develop standards for sound pressure levels in the entire specified frequency range that are acceptable for the most sensitive recipients. For terrestrial and riparian ecosystems and protected areas, natural test subjects are birds, for which noise levels of 35-40 dBA do not cause pathological changes in behavior and physiological processes. This level can tentatively be considered as maximum permissible for man-made noise and for the noise of ports in particular. More reliable results will be given by regulating the permissible sound pressure levels in the entire frequency range based on reactions of the most sensitive recipients in each octave.

HYGIENIC ASSESSMENT OF INTERVENTIONS FOR REDUCING EXCESSIVE ACOUSTIC IMPACT ON RESIDENTIAL AREAS

Introduction. The most important external sources of excessive noise levels on the territories of residential development are transportation sources (road, rail, aviation). The aim of the present study is the hygienic assessment of the acoustic situation in the areas in the zone of influence of traffic flows and currently used measures to reduce the excess acoustic impact on residential premises. Material and methods. The studies were carried out on the territories along the roads and Railways, with different intensity of traffic flows in accordance with GOST 23337-2014 Noise. Methods of noise measurement in residential areas and in the premises of residential and public buildings, MUK 4.3.2194-07 “Methods of noise measurement in residential areas and in the premises of residential and public buildings.” Experimental studies of materials used for the construction of acoustic screens were carried out. Here were investigated window units were used to reduce external noise in the house. Sound pressure levels in octave bands (dB) and sound levels (dBA) in the sound-measuring reverberation chamber were measured in accordance with GOST 27296-2012. Results. Exceeding the permissible equivalent noise levels at a distance from 2 to 7.5 m from the roadway of vehicles in the daytime reaches 25-32 dBA. Noise from railway transport at a distance of 25 m from the source in terms of the equivalent sound level for freight transport is of 77 dBA, maximum - 83 dBA; for cargo transport, Sapsan, Lastochka, Allegro identical data were obtained; for passenger trains, the equivalent sound level accounted for 71 dBA, for electric trains - 66-69 dBA. Exceeding the standards for octave frequencies were most often observed at low frequencies from 31.5 to 500 Hz. The air noise insulation index (dB) is higher for the concrete and wood chips material, i.e. the material with higher density. The study of the parameters of the window blocks allowed us to establish all the studied samples to provide a reduction in the equivalent noise level by more than 20 dBA, but differ in the spectral characteristics of noise damping. Conclusion. Traffic flows create excessive noise levels in urban and rural settlements and impair the quality of life of the population. The effectiveness of existing measures aimed to mitigating noise in the source of generation by both road and rail transport has been exhausted. Acoustic screens in high-rise buildings have very limited efficiency. An option to reduce the adverse impact of external noise on public health is the construction of buildings protected from noise. Placement of buildings along the linear objects of road and rail transport should be provided at the stage of planning of quarters, the construction of such buildings should be carried out on special projects. When designing and building, special attention should be paid to the window units used and the quality of their installation. Window blocks should be selected on the basis of frequency characteristics of noise attenuation.

Methods for assessing safe seniority in high noise conditions

A method for estimating the maximum allowable length of service in high noise conditions based on the calculation of the allowable working dose when working in working conditions with exceeding hygienic standards, which is based on the “equal energy” rule applicable to any factor of the each working environment is presented. A method of calculating the dose of the permissible noise level during the entire seniority LCT is proposed, on the assumption of threshold permissible values of the sound level (equivalent sound level), which allows implementing an occupational safety management strategy, both through organizational measures (transfer to areas with acceptable noise levels) and the development of measures to improve working conditions and safety. The dose principle of hygienic rationing allows us to estimate the actual load on the employee’s sensory systems and the required number of days of rest or work with reduced noise levels. To solve this problem, in the presented methodology, analytical methods that are proposed, allows to count the number of days of rest (or work with a reduced dose of noise) during a shift, month or year depending on the value of the equivalent noise level LA and the duration of its impact.

The Use of Artificial Intelligence as a Tool Supporting Sustainable Development Local Policy

This paper addresses the problem of noise in spa protection areas. Its aim is to determine the delimitation of the areas that exceed a permissible noise level around the sanatorium on the example of a health resort in Inowrocław. The determination of the exceedance of permissible noise levels allows us to develop directly effective local policy tools to be included in planning documents. In order to reduce noise infiltration, it is important to define environmental priorities. Taking into account their impact on the health of users in the protection area, environmental priorities enable us to introduce additional elements to street architecture. In order to properly manage space, in accordance with the idea of sustainable development, zones of environmental sensitivity—and their socio-environmental vulnerability—have been designated for assessing damage (exceeding permissible noise in health facilities) and defining methods of building resilience (proper management). This has provided the basis for a natural balance optimized for the people living in these areas. To achieve the goal above, non-linear support vector machine (SVM) networks were used. This technique allows us to classify the linearly inseparable data and to determine the optimal separation margin. The boundaries of the areas which exceeded permissible noise levels (separation margin) were estimated on the basis of noise pollution maps, created by means of the SVM technique. Thus, the study results in establishing buffer zones where it is possible to use varied land utilization in terms of form and function, as described in the planning documents. Such an activity would limit the spread of noise.

АНАЛІЗ МЕТОДІВ ЗНИЖЕННЯ АВІАЦІЙНОГО ШУМУ В ДЖЕРЕЛІ І НА МІСЦЕВОСТІ

Currently, the topic of research of the aircraft noise influence on the environment is relevant. Aircraft and engine developers are constantly exploring ways to reduce noise following the new standards of the ICAO Committee (CAEP), whose main task is to protect the environment from the effects of aviation, to provide a comfortable environment for people exposed to aircraft noise and harmful substances. By limiting the permissible noise level of aircraft, CAEP initiates aircraft manufacturers to introduce the latest noise reduction technologies in their design. Measurement of aircraft noise is obviously an important type of research not only in the aircraft industry. The existing airports in the course of reconstruction, and new ones at the project development stage, should be mandatory tested on indicators of aircraft noise, which will penetrate into the surrounding area, including settlements of various sizes. Currently, scientists from different countries are making significant efforts to reduce the turbine noise of existing and prospective civil aircraft. Of course, nowadays, external jamming methods are commonly used. At the same time, an important way to reduce engine noise was the widespread use of so-called sound-absorbing structures. This article describes the direction of reducing the level of aircraft noise at the source and on the ground, near airports. To reduce the noise in the source of noise, the ways to reduce the turbulence of the streamlined aerodynamic bearing surfaces are considered by reducing their inductive resistance and matching the flow of gas in power plants. It is shown that the implementation of such approaches in modifications of domestic passenger and transport aircraft gives a positive result. When solving the problem of reducing noise on the ground, the study analyzed the effect of aviation noise on the population living near the airport as an example. The necessity of using soundproofing means in residential areas to reduce noise exposure is shown. An analysis of the effects of noise exposure is given. In conclusion, the preliminary results obtained in the course of research are presented.

An evaluation of the Sennheiser HDA 280-CL circumaural headphone for use in audiometric testing

Objective: Evaluation of the Sennheiser HDA 280-CL circumaural headphone for the determination of (1) equivalent threshold sound pressure levels (ETSPL) for 125–18,000 Hz.; (2) real ear attenuation (250–8000 Hz); (3) insertion loss (63–18,000 Hz); (4) frequency response (125–18,000 Hz); (5) total harmonic distortion (THD) (125–10,000 Hz); and, (6) linearity (11,200–18,000 Hz).Study Sample: Twenty-five normal hearing adults aged 18–25 participated in (1) and (2).Design: (1) Hearing thresholds were measured using the Sennheiser HDA 280-CL. Frequency specific ETSPL values were calculated in an artificial ear. (2) Sound field thresholds were measured with the ears open and covered with the headphone to obtain the real ear attenuation thresholds (REAT). These values were used to determine the maximum permissible ambient noise levels (MPANL). (3) A B&K HATS mannequin recorded the output levels of a broadband pink noise with the ears open and covered with the headphones. (4, 5) The frequency response, THD and linearity were measured in an artificial ear.Results: Values for ETSPL, REAT, MPANL, insertion loss, as well as measures of frequency response, THD and linearity are presented.Conclusions: The Sennheiser HDA 280-CL meets the requirements for audiometric testing and the values presented can be used for calibration.

THE COMPARATIVE ANALYSIS OF THE NOISE CHARACTERISTICS OF LAND RAIL TRANSPORT AND EFFICIENCY OF NOISE PROTECTION MEASURES

The article gives an analysis of the noise characteristics of modern types and systems of railway, monorail and urban land rail transport. The requirements of external, Russian and industry normative documents to the permissible noise levels in the residential area and on the land rail transport are considered. The results of the instrumental noise measurements on the route of the Moscow monorail transport system and in laboratory conditions are given. An overview of the best available technologies for noise protection in transport is presented. The measures of reducing the noise generated by monorail current collection devices are proposed.

Noise: The disease of urban environments: Management and protection measures

Communal noise is the noise that comes from living together. It is the noise in the interior or exterior, whether in the working or living environment, spaces in public buildings or open public areas. The issue of communal noise has been partially resolved on paper by lows and by-lows on the permissible noise levels in the environment. However, the question is how much noise the community will tolerate, i.e, at what point citizens will start fighting noise. Numerous cities have signed strict regulations for reducing noise levels, both day and night, with a proposal for permitted limits. This paper presents commonly used methods for managing and protecting against the harmful effects of noise.

Noise Levels and Frequency Response from Religious Houses in Portharcourt City Local Government Area

Introduction: Noise pollution in churches is one of the health challenges facing developing nations of the world. Both Pastors/Reverends are exposed to different sound levels during church services, many of which can last for hours. According to the Nigerian National Environmental standard and regulation Act 2007, the maximum permissible noise level in worship centers should not exceed 75 dB and Nigeria being the highest church proliferation in the world makes it imperative to carry out this research. Aim: the aim of this study is the measure the equivalent noise levels with their corresponding frequency levels at varying distances from the source and quantify the noise pollution levels in churches and mosques in Port Harcourt. Method: a total of 11 Pentecostal churches, 5 orthodox churches and 3 central mosques were randomly selected. This study was carried out between July and August, 2017. Sound pressure level meter was used to measure the sound levels under the weighted range in churches on Sundays between the hours of 7.30 to 12.0 pm and on Fridays in mosques between the hours of 1.30 to 3.00pm afternoon session and evening at 6.00pm. Data obtained was analyzed using ms-excel. Result: Average indoor and outdoor equivalent noise level in pentecostal churches are 95.1 dB(A) and 79.5 dB(A) respectively while that for orthodox churches are 93.6 dB(A) and 77.9 dB(A) respectively. The average indoor and outdoor equivalent noise levels in mosques are 72.1 and 100.6 dB(A). The frequency of the noise ranges from 310.75 to 785.30 Hz in Pentecostal, 482.60 to 749.02 Hz in Orthodox churches and 438.63 to 620.36 Hz in mosques. The highest noise pollution level in churches and mosques recorded are 121.18, 119.38 and 123.48 dB for pentecostal, orthodox and mosques respectively. Conclusion: all the noise pollution levels recorded in the churches and mosques are higher than the safe permissible limits of sound of 75 dB thus making it unhealthy, unsafe for the worshippers. Therefore there is need for implementation of the noise regulation laws in churches in Nigeria in order to reduce the risk of hearing loss.

Evaluation of on-the-job noise exposure in the case of bartenders

In places associated with the entertainment industry in which music is performed or played, sounds with high sound pressure levels may occur. Such exposure is a threat to both people spending their free time at concerts, in discos or pubs, as well as employees in these places. The aim of the research conducted in 2017 was to assess on-the-job noise exposure in the case of bartenders at various premises of the entertainment industry. The measurements included 15 entertainment venues in Łódź, out of which 3 were selected: a music club, disco and pub. The exposure measurements were taken together for 4 work stations for bartenders using individual dosimetry in accordance with the PN-EN ISO 9612: 2011 standard. A total of 64 measurements were carried out, which showed that the equivalent sound levels A at the bartenders' workplaces vary considerably depending on the type of premises and the day of the week and the range of 67.6-108.7 dB. The highest sound levels occurred during the weekend (Fridays and Saturdays). The determined daily noise exposure levels exceeded the threshold of preventive action (80 dB) in 95% of the analyzed cases. Exceeding the maximum permissible noise level (NDN = 85 dB) was found in 66% of cases. It has been found that on-the-job noise levels in the case of bartenders significantly exceed the acceptable values of exposure levels and pose a risk of hearing damage. Med Pr 2018;69(6):633-641.

Measurement of low-frequency noise during CNC machining and its assessment

The aim of the paper is to point out the necessity to measure noise exposure by means of weighting filter Z, not only weighting filter A, which is prescribed by the standard. The measurement in the paper confirms the various acoustic pressure levels using weighting filter A and weighting filter Z at a low-frequency from 16 Hz to a frequency of 100 Hz. Such measurements suggest that the way in which this noise is evaluated must be adjusted. Due to the risks of exposure to excessive noise, the legislation prescribes regular measurement of permissible noise levels. European legislation and technical standards (e.g. ISO 1996) prescribe “weighting A” in case of such noise. However, this does not respect the energetic effect of sound on the auditory organ, as well as the neuropsychic and cardiovascular system of humans and sensory-motor functions. Experiments and research show that when evaluating low-frequency sounds with strong acoustic energy, the evaluation procedures should be adjusted to the impact of real acoustic energy affecting humans.The noise exposure measurement described in the paper was carried out during production of cars parts that were machined by a CNC machine. The measurement results showed that when weighting filter Z was used, the acoustic pressure levels were higher than those measured by weighting filter A by 22.8 dB. The measured equivalent LZeq values for the given work activity were 73.4 dB(Z) and LAeq was 50.6 dB(A). At low frequencies, this difference was the most pronounced, up to several times higher.

Out-of-Booth Testing with Noise-canceling Earphones

Out-of-Booth Testing with Noise-canceling Earphones

Gradient-Free Two-Point Methods for Solving Stochastic Nonsmooth Convex Optimization Problems with Small Non-Random Noises

We study nonsmooth convex stochastic optimization problems with a two-point zero-order oracle, i.e., at each iteration one can observe the values of the function’s realization at two selected points. These problems are first smoothed out with the well-known technique of double smoothing (B.T. Polyak) and then solved with the stochastic mirror descent method. We obtain conditions for the permissible noise level of a nonrandom nature exhibited in the computation of the function’s realization for which the estimate on the method’s rate of convergence is preserved.

Noise characterization of oil and gas operations

ABSTRACTIn cooperation with The Colorado Oil and Gas Conservation Commission, researchers at Colorado State University performed area noise monitoring at 23 oil and gas sites throughout Northern Colorado. The goals of this study were to: (1) measure and compare the noise levels for the different phases of oil and gas development sites; (2) evaluate the effectiveness of noise barriers; and (3) determine if noise levels exceeded the Colorado Oil and Gas Conservation Commission noise limits. The four phases of oil and gas development include drilling, hydraulic fracturing, completion and production. Noise measurements were collected using the A- and C-weighted sound scales. Octave band analysis was also performed to characterize the frequency spectra of the noise measurements. Noise measurements were collected using noise dosimeters and a hand-held sound-level meter at specified distances from the development sites in each cardinal direction. At 350 ft (107 m), drilling, hydraulic fracturing, and completion sites without noise barriers exceeded the maximum permissible noise levels for residential and commercial zones (55 dBA and 60 dBA, respectively). In addition, drilling and hydraulic fracturing sites with noise barriers exceeded the maximum permissible noise level for residential zones (55 dBA). However, during drilling, hydraulic fracturing, and completion operations, oil producers are allowed an exception to the noise permissible limits in that they only must comply with the industrial noise limit (80 dBA). It is stated in Rule 604.c.(2)A. that: “Operations involving pipeline or gas facility installation or maintenance, the use of a drilling rig, completion rig, workover rig, or stimulation is subject to the maximum permissible noise levels for industrial zones (80dBA).”[8] Production sites were within the Colorado Oil and Gas Conservation Commission permissible noise level criteria for all zones. At 350 ft (107 m) from the noise source, all drilling, hydraulic fracturing, and completion sites exceeded 65 dBC. Current noise wall mitigation strategies reduced noise levels in both the A- and C-weighted scale measurements. However, this reduction in noise was not sufficient to reduce the noise below the residential permissible noise level (55 dBA).

Exceeding the permissible noise levels from rail transport in the Kysuce region

Rail transport is a source of noise that has disturbing effects on the environment. Adverse noise emissions must be observed and at the same time keep the permissible noise levels that depend on the type of protected area given by the Slovak legislation. The paper deals with compliance and analysis of these permitted noise values in some selected locations of the railway line in the Kysuce region.

A theoretical overview of road hump effects on traffic noise in improving residential well-being

Abstract Previous studies have stated that an urban residential area's living quality is threatened by noise annoyance, of which traffic noise is considered the main contributor. This paper aims to discuss if the speed-reducing benefits of existing road humps make them viable as a noise-reducing measure, particularly when the humps do not comply with existing guidelines. The methods used were a literature review and paired-sample T-tests to test the significance of changes in traffic noise at selected road humps. The literature and data showed that noise levels were still high at roads with road humps, due to the frequency of vehicle accelerations and decelerations near the road humps. The noise levels are also above the permissible noise level for Malaysian residential areas. This suggests that road humps are less viable especially when drivers change their speed of vehicles appreciably when approaching the road humps.

Thoughts on MIL-STD-1474E noise limits

Department of Defense Design Criteria Standard Noise Limits (MIL-STD-1474E), published in 2015, is a standard developed for the acquisition of military materiel specifies the maximum permissible noise levels produced by military systems and the test requirements for measuring these levels. It is intended for use by equipment designers and manufacturers, covering typical operational conditions and provides noise limits shall not be exceeded if the materiel is to be acceptable to the procuring activity. It is not intended to be used for health hazard assessments for personnel exposed to impulsive noises. Appendix B established the acquisition requirements for impulsive noise limits. Oddly, the standard allows the use of two different methods, although the U.S. Army must use a method that utilizes the Auditory Hazard Assessment Algorithm for Humans. This paper describes some obstacles in using this appendix for acquisition of weapons systems, including the curious use of two completely different methods for ...

Affordable headphones for accessible screening audiometry: An evaluation of the Sennheiser HD202 II supra-aural headphone

Objective: Evaluation of the Sennheiser HD 202 II supra-aural headphones as an alternative headphone to enable more affordable hearing screening. Design: Study 1 measured the equivalent threshold sound pressure levels (ETSPL) of the Sennheiser HD 202 II. Study 2 evaluated the attenuation of the headphones. Study 3 determined headphone characteristics by analyzing the total harmonic distortion (THD), frequency response and force of the headband. Study sample: Twenty-five participants were included in study 1 and 15 in study 2 with ages ranging between 18 and 25. No participants were involved in study 3. Results: The Sennheiser HD 202 II ETSPLs (250–16000 Hz) showed no significant effects on ETSPL for ear laterality, gender or age. Attenuation was not significantly different (p > 0.01) to TDH 39 except at 8000 Hz (p < 0.01). Maximum permissible ambient noise levels (MPANL) were specified accordingly. The force of the headband was 3.1N. THD measurements showed that between 500 and 8000 Hz intensities of 90 dB HL and higher can be reached without THD >3%. Conclusion: Sennheiser HD 202 II supra-aural headphones can be used as an affordable headphone for screening audiometry provided reported MPANLs, maximum intensities and ETSPL values are employed.