scholarly journals Estimating Sound Exposure Levels Due to a Broadband Source over Large Areas of Shallow Sea

2022 ◽  
Vol 10 (1) ◽  
pp. 82
Author(s):  
Denis Manul’chev ◽  
Andrey Tyshchenko ◽  
Mikhail Fershalov ◽  
Pavel Petrov
Keyword(s):  
Sound Propagation ◽  
Acoustic Noise ◽  
Pulse Signal ◽  
Source Spectrum ◽  
Exposure Level ◽  
Propagation Modeling ◽  
Sound Exposure ◽  
3D Sound ◽  
Exposure Levels ◽  
Sea Area

3D sound propagation modeling in the context of acoustic noise monitoring problems is considered. A technique of effective source spectrum reconstruction from a reference single-hydrophone measurement is discussed, and the procedure of simulation of sound exposure level (SEL) distribution over a large sea area is described. The proposed technique is also used for the modeling of pulse signal waveforms at other receiver locations, and results of a direct comparison with the pulses observed in the experimental data is presented.

scholarly journals Effects of Background Sounds on Annoyance Reaction to Foreground Sounds in Psychoacoustic Experiments in the Laboratory: Limits and Consequences

2019 ◽  
Vol 9 (9) ◽  
pp. 1872 ◽  
Author(s):  
Armin Taghipour ◽  
Eduardo Pelizzari
Keyword(s):  
Sound Propagation ◽  
Background Level ◽  
Sound Level ◽  
Exposure Level ◽  
Block Designs ◽  
Sound Exposure ◽  
Balanced Incomplete Block Designs ◽  
Balanced Incomplete Block ◽  
Realistic Scenes ◽  
Noise Production

In a variety of applications, e.g., psychoacoustic experiments, virtual sound propagation demonstration, or synthesized noise production, noise samples are played back in laboratories. To simulate realistic scenes or to mask unwanted background sounds, it is sometimes preferable to add background ambient sounds to the noise. However, this can influence noise perception. It should be ensured that either background sounds do not affect, e.g., annoyance from foreground noise or that possible effects can be quantified. Two laboratory experiments are reported, in which effects of mixing background sounds to foreground helicopter samples were investigated. By means of partially balanced incomplete block designs, possible effects of three independent variables, i.e., helicopter’s sound exposure level, background type, and background sound pressure level were tested on the dependent variable annoyance, rated on the ICBEN 11-point numerical scale. The main predictor of annoyance was helicopter’s sound exposure level. Stimuli with eventful background sounds were found to be more annoying than those with less eventful background sounds. Furthermore, background type and level interacted significantly. For the major part of the background sound level range, increasing the background level was associated with increased or decreased annoyance for stimuli with eventful and less eventful background sounds, respectively.

Aircraft noise-induced awakenings are more reasonably predicted from relative than from absolute sound exposure levels

2013 ◽  
Vol 134 (5) ◽  
pp. 3645-3653 ◽  
Author(s):  
Sanford Fidell ◽  
Barbara Tabachnick ◽  
Vincent Mestre ◽  
Linda Fidell
Keyword(s):  
Aircraft Noise ◽  
Sound Exposure ◽  
Exposure Levels

Frequency and Time Numerical Solutions of 3D Sound Propagation in Open and Closed Spaces

2000 ◽  
Vol 7 (4) ◽  
pp. 247-261 ◽  
Author(s):  
António Tadeu ◽  
Julieta António ◽  
Luís Godinho
Keyword(s):  
Numerical Solutions ◽  
Sound Propagation ◽  
3D Sound

scholarly journals Background noise analysis in urban airport surroundings of Brazilian cities, Congonhas Airport, São Paulo

2016 ◽  
Vol 50 (0) ◽  
Author(s):  
Fabio Scatolini ◽  
Cláudio Jorge Pinto Alves
Keyword(s):  
Traffic Control ◽  
Background Noise ◽  
Noise Analysis ◽  
Exposure Level ◽  
Noise Levels ◽  
Sound Exposure ◽  
Operational Characteristics ◽  
Data Compilation ◽  
Noise Measurements ◽  
Noise Data

ABSTRACT OBJECTIVE To perform a quantitative analysis of the background noise at Congonhas Airport surroundings based on large sampling and measurements with no interruption. METHODS Measuring sites were chosen from 62 and 72 DNL (day-night-level) noise contours, in urban sites compatible with residential use. Fifteen sites were monitored for at least 168 hours without interruption or seven consecutive days. Data compilation was based on cross-reference between noise measurements and air traffic control records, and results were validated by airport meteorological reports. Preliminary diagnoses were established using the standard NBR-13368. Background noise values were calculated based on the Sound Exposure Level (SEL). Statistic parameters were calculated in one-hour intervals. RESULTS Only four of the fifteen sites assessed presented aircraft operations as a clear cause for the noise annoyance. Even so, it is possible to detect background noise levels above regulation limits during periods of low airport activity or when it closes at night. CONCLUSIONS All the sites monitored showed background noise levels above regulation limits between 7:00 and 21:00. In the intervals between 6:00-6:59 and 21:00-22:59 the noise data, when analyzed with the current airport operational characteristics, still allow the development of additional mitigating measures.

scholarly journals Repeated Noise Exposure Does Not Reach Hazardous Levels During Total Joint Arthroplasty

2020 ◽  
Vol 185 (9-10) ◽  
pp. e1551-e1555
Author(s):  
Sean E Slaven ◽  
Benjamin M Wheatley ◽  
Daniel L Christensen ◽  
Sameer K Saxena ◽  
Robert J McGill
Keyword(s):  
Noise Exposure ◽  
Weighted Average ◽  
Sound Level ◽  
Health Concern ◽  
Exposure Level ◽  
Total Knee ◽  
Time Weighted Average ◽  
Exposure Levels ◽  
Occupational Standards ◽  
Level Meter

Abstract Introduction Noise exposure is an occupational health concern for certain professions, especially military servicemembers and those using power tools on a regular basis. The purpose of this study was to quantify noise exposure during total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases compared to the recommended standard for occupational noise exposure. Materials and Methods A sound level meter was used to record cumulative and peak noise exposure levels in 10 primary THA and 10 primary TKA surgeries, as well as 10 arthroscopy cases as controls. Measurements at the distance of the surgeon were taken in all cases. In TKA cases, measurements were taken at 3 feet and 8 feet from the surgeon, to simulate the position of the anesthetist and circulating nurse, respectively. Results Time-weighted average was significantly higher in THA (64.7 ± 5.2 dB) and TKA (64.5 ± 6.8 dB) as compared to arthroscopic cases (51.1 ± 7.5 dB, P < 0.001) and higher at the distance of the surgeon (64.5 ± 6.8 dB) compared to the anesthetist (52.9 ± 3.8 dB) and the circulating nurse (54.8 ± 11.2 dB, P = 0.006). However, time-weighted average was below the recommended exposure level of 85 dB for all arthroplasty cases. Peak levels did not differ significantly between surgery type or staff role, and no values above the ceiling limit of 140 dB were recorded. Surgeon’s daily noise dose percentage per case was 1.78% for THA and 2.04% for TKA. Conclusion Noise exposure in THA and TKA was higher than arthroscopic cases but did not exceed occupational standards. A daily dose percentage of approximately 2% per case indicates that repeated noise exposure likely does not reach hazardous levels in modern arthroplasty practice.

scholarly journals Evaluación de niveles de exposición electromagnética causados por las estaciones base de Telefonía Móvil Celular [Assessment for electromagnetic exposure level caused by cellular mobile transmitting antennas in base station]

2014 ◽  
Author(s):  
Walder de Jesús Canova García
Keyword(s):  
Electromagnetic Field ◽  
Base Station ◽  
Base Stations ◽  
Exposure Level ◽  
Field Exposure ◽  
Palabras Clave ◽  
Exposure Levels ◽  
Mobile Base Station ◽  
Cellular Mobile ◽  
Mobile Base

Resumen El creciente número de estaciones base de telefonía móvil celular alrededor de sectores residenciales o tránsito de personas, causa preocupación en la comunidad sobre si la radiación de campos electromagnéticos puedan causar riesgos en la salud. Internacionalmente existen estándares que establecen límites a las diversas fuentes de campos electromagnéticos para garantizar que se minimizan los riesgos en la salud. Cada país adopta dentro de su legislación algún estándar o recomendación y exige su cumplimiento a los operadores de estaciones de telecomunicaciones, por ejemplo en Colombia rige el decreto 195 de 2005. El artículo presenta una evaluación, basados en mediciones técnicas en el 2010, para obtener los niveles de exposición a campos electromagnéticos generados por las antenas instaladas en las estaciones base de telefonía móvil. Luego aparece el procedimiento general de mediciones, donde incluye el plan ejecutorial de mediciones, la configuración de la instrumentación y la caracterización de los lugares y puntos de medición. Por último, los resultados medidos en algunos lugares, donde las antenas de transmisión cumplían con la normativa adoptada en Colombia. Palabras Clave: Exposición a campos Electromagnéticos, Estaciones base de Telefonía móvil celular, Mediciones de banda angosta.   Abstract The growth of installations of transmitting antennas on base stations surrounding residential spaces or person traffic causes concerns in the community, about whether the radiation of electromagnetic fields of transmitting antennas in mobile base station can generate health risk. Over the world, there are standards that establish maximum levels permitted to different electromagnetic field sources to accomplish security ranges for health risks. Each country adopts in their legislation some international standard and requires to telecommunication operators stations for its compliance. In Colombian, the decree 195 of 2005 is still valid. This article shows an assessment, based on technical measurements developed in 2010, to acquire the electromagnetic field exposure levels generated by transmitting antennas installed on Mobile Base Station. This assessment includes the measurement system procedure: plan of measurement, instrumental configuration, and characterization of measurement places. Finally, here presents the measured results in some places, which exposure levels satisfied the adopted legislation in Colombia. Keywords: Electromagnetic Field Exposure, Mobile Base Stations, Narrowband Measurement.

METHODOLOGICAL FOUNDATIONS FOR SUBSTANTIATING SAFE LEVELS OF EXPOSURE TO ARTIFICIAL NANOMATERIALS (FOR EXAMPLE, CARBON NANOTUBES)

2021 ◽  
Author(s):  
G.A. Timerbulatova ◽  
◽  
Keyword(s):  
Carbon Nanotubes ◽  
Harmful Effect ◽  
Exposure Level ◽  
In Vivo Experiments ◽  
World Markets ◽  
Dose Concentration ◽  
Exposure Levels ◽  
Planning Of Experiments

Abstract: The unique physicochemical properties of carbon nanotubes allow them to be used in many fields. The global nanomaterials market is growing every year. An important step in introducing products to the domestic and world markets is to determine the safe exposure levels of CNTs. Establishing a corporate standard can serve as a preliminary stage before the approval of a state hygiene standard. Justification of the corporate standard is carried out in in vitro and in vivo experiments. The planning of experiments should be carried out taking into account the target organ under the influence of CNT - the respiratory system. The recommended dose / concentration range for experiments should include doses / concentrations derived from calculated and literature data. A necessary step is to obtain homogeneous dispersions in which CNTs become bioavailable for biological systems. During in vitro and in vivo experiments, the exposure level is determined at which no harmful effect is observed and / or the lowest level of exposure at which there is a harmful effect on the cell culture / respiratory tract of animals.

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