A sound exposure level study near the Camden Sound area, Browse Basin

2011 ◽  
Vol 51 (2) ◽  
pp. 705
Author(s):  
Andrew Long ◽  
Alec Duncan ◽  
Amos Maggi ◽  
Jeremy Colman ◽  
Jens Wisløff ◽  
...  
Keyword(s):  
Sound Level ◽  
Seismic Survey ◽  
Exposure Level ◽  
Underwater Sound ◽  
Marine Animals ◽  
Worst Case ◽  
Sound Exposure ◽  
Sound Levels ◽  
Marine Seismic ◽  
Threshold Criteria

A common approach to environmental risk assessment when assessing the level of risk to marine animals during marine seismic surveys is to compare either measured or modelled estimates of underwater sound levels to a known sound level threshold criteria. Over the years, a number of measures have been used to calculate and characterise underwater sound thresholds, including: sound pressure level (SPL), a root mean square (RMS) calculation, and—more recently—sound exposure level (SEL). SEL was suggested in 2007 by an expert panel of researchers as an appropriate measure to reduce the risk of temporary threshold shift (TTS) occurring in marine animals. Petroleum Geo-Services (PGS) commissioned an SEL study in preparation for a large MultiClient 3D seismic survey planned for the environmentally sensitive Camden Sound area, Western Australia, in late 2010. The Centre for Marine Science and Technology (CMST) at Curtin University built a comprehensive bathymetric model of the Camden Sound area and used two seabed geoacoustic models, with sand/limestone—as worst case, most reflective—and silt—as best case, least reflective. Acoustic propagation modelling over the frequency range of 8–1 kHz was used to build 3D maps of sound levels throughout all areas relevant to the seismic survey. The CMST SEL modelling results were integrated with other airgun array and SEL modelling pursued by PGS, and represent part of a broader environmental management strategy by PGS. Discussion is also given to other variants of SEL modelling.

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.

Subtraction Analysis for Predicting the Propagation Effects of Aircraft Noise

2021 ◽  
Vol 263 (2) ◽  
pp. 4843-4850
Author(s):  
Yiming Wang ◽  
Kai Ming Li
Keyword(s):  
Time History ◽  
Federal Aviation Administration ◽  
Aircraft Noise ◽  
Design Tool ◽  
Exposure Level ◽  
Directivity Effect ◽  
Sound Exposure ◽  
Sound Levels ◽  
Propagation Effects ◽  
Recorded Data

In 2013, the Federal Aviation Administration and Volpe National Transportation System Center conducted a series of acoustic measurements with a propeller driven aircraft operating in the regions near Houston, Texas. The recorded data on octave band sound levels, aircraft locations, temperature and wind speed profiles were used in the current study to quantify the uncertainties for predicting the propagation effects of aircraft noise. Use of the Aviation Environmental Design Tool (AEDT) was explored for its accuracy and validity in real world scenarios offered by the dataset. The sound exposure level (SEL) data for each section of a flight path was used instead of the time history data for reducing the directivity effect of the sound source due to the change in its relative positions with the receivers. A subtraction-based method was introduced to analyze the propagation effect in which the SELs between two receiver locations were compared. The use of the subtraction method reduces the possible influences of the sound power variations along the flight paths. The measured data for a spiral and a level flight event were presented and the AEDT predictions on the propagation effects were examined in this paper.

scholarly journals PROBABILITY OF OCCURRENCE OF HEALTH AND SAFETY RISKS ON SCAFFOLDING CAUSED BY NOISE EXPOSURE

2018 ◽  
Vol 24 (6) ◽  
pp. 437-443 ◽  
Author(s):  
Marek Jabłoński ◽  
Iwona Szer ◽  
Jacek Szer
Keyword(s):  
Noise Exposure ◽  
Health And Safety ◽  
Noise Pollution ◽  
Sound Level ◽  
Work Environments ◽  
Exposure Level ◽  
Sound Levels ◽  
Safety Risks ◽  
Noise Measurements ◽  
The Impact

The paper presents the results of measurements for one hundred and ten scaffolds located in five cities in different parts of Poland. Measurements were made between April of 2016 and October of 2017. The environmental tests performed on scaffoldings were focused mainly on the sound level. The parameters on which we base our analysis are the value of C-weighted peak sound levels and daily noise exposure level. The noise that affects construction workers on scaffolding may influence the behaviour of workers and increase the risk of accidents. And at the same time, noise exposure laws facilitate identification of high noise-emitting activities and provide effective preventive measures that reduce noise pollution and improve work environments. The analyses carried out confirmed the qualitatively expected dependencies, and allowed us to quantify the impact of noise to which scaffolding workers are exposed. In summary, noise measurements on scaffoldings can be a valuable aid in improving working conditions. The analysis of research results allows understanding hazards related to noise in an accessible way. They provide the opportunity to modify the professional environment so that it is more employee-friendly and does not expose them to problems occurring in a noisy work environment.

scholarly journals The Uncertainty of Noise Composed of Separate Sound Events

2016 ◽  
Vol 41 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Rufin Makarewicz ◽  
Roman Gołębiewski
Keyword(s):  
Noise Pollution ◽  
Sound Level ◽  
Time Interval ◽  
Exposure Level ◽  
Transportation Noise ◽  
Sound Exposure ◽  
Sound Event ◽  
Time Average ◽  
Regulations And Guidelines

Abstract Transportation noise is a main source of noise pollution. It is assumed that it consists of recognizable noise events which come from moving aircrafts, trains and boats. The noise of an isolated sound event is assessed by the sound exposure level, LAE. Much legislation and many regulations and guidelines employ the A-weighted time-average sound level, LAeq,T, with the time interval T of one hour or longer. LAE measurements enable an approximation of LAeq,T. The key point is the uncertainty of this approximation. It has been shown that an increase in the number of LAE categories brings about a decrease in uncertainty. For illustrative purposes, LAE measurements of aircrafts taking off and landing were carried out.

scholarly journals University Marching Band Members Noise Dosages and Hearing Health-Related Knowledge

2021 ◽  
Vol 18 (21) ◽  
pp. 11497
Author(s):  
Nilesh J. Washnik ◽  
Jeffrey A. Russell ◽  
Ishan Bhatt ◽  
Rebecca Meier ◽  
Olivia Chuzie ◽  
...  
Keyword(s):  
Sound Level ◽  
Marching Band ◽  
Band Director ◽  
Sound Exposure ◽  
Band Students ◽  
Sound Levels ◽  
Dose Limits ◽  
Health Related ◽  
Hearing Health ◽  
High Sound

Objectives: (1) To measure sound exposures of marching band and non-marching band students during a football game, (2) to compare these to sound level dose limits set by NIOSH, and (3) to assess the perceptions of marching band students about their hearing health risk from loud sound exposure and their use of hearing protection devices (HPDs). Methods: Personal noise dosimetry was completed on six marching band members and the band director during rehearsals and performances. Dosimetry measurements for two audience members were collected during the performances. Noise dose values were calculated using NIOSH criteria. One hundred twenty-three marching band members responded to a questionnaire analyzing perceptions of loud music exposure, the associated hearing health risks, and preventive behavior. Results: Noise dose values exceeded the NIOSH recommended limits among all six marching band members during rehearsals and performances. Higher sound levels were recorded during performances compared to rehearsals. The audience members were not exposed to hazardous levels. Most marching band members reported low concern for health effects from high sound exposure and minimal use of HPDs. Conclusion: High sound exposure and low concern regarding hearing health among marching band members reflect the need for comprehensive hearing conservation programs for this population.

Prediction and Monitoring of Underwater Sound Levels from the Implosion of a Reinforced Concrete Bridge Pier

2017 ◽  
Vol 2628 (1) ◽  
pp. 47-57
Author(s):  
Paul R. Donavan ◽  
James Reyff ◽  
Carrie Janello
Keyword(s):  
San Francisco ◽  
Peak Pressure ◽  
Underwater Sound ◽  
Surface Reflection ◽  
Sound Exposure ◽  
Reinforced Concrete Bridge ◽  
Sound Levels ◽  
Exposure Levels ◽  
And Performance ◽  
Peak Pressures

After the completion of the new east span of the San Francisco–Oakland Bay Bridge in California, large concrete piers of the old span needed to be demolished. To consider using controlled blasting for this action, hydroacoustic levels were predicted and monitored with regard to specified fish and marine mammal criteria. The metrics included peak pressure and sound exposure levels at distances from 25 to more than 4,000 ft from the pier. For peak pressure, the measured levels were slightly higher than estimated, although for sound exposure levels, the measured levels were somewhat lower than estimated because of the effect of surface reflection. A blast attenuation system consisting of a wide bubble stream was used to minimize the hydroacoustic levels in the water surrounding the pier. The implosion event consisted of 588 individual charge detonations ranging from 35 to 21 lb (15.9 to 9.5 kg/delay) spaced 9 ms apart. Although there were 135 individual detonations of the larger 35-lb charges, the highest peak pressures varied in level by 10 to 15 dB during the course of the implosion. The methods for predicting the levels, measured results, analysis of data, and performance of the blast attenuation system are reviewed.

Sound Levels in Classrooms and Effects on Self-Reported Mood among School Children

2003 ◽  
Vol 96 (3_suppl) ◽  
pp. 1289-1299 ◽  
Author(s):  
Pär Lundquist ◽  
Kjell Holmberg ◽  
Lage Burström ◽  
Ulf Landström
Keyword(s):  
School Children ◽  
Sound Level ◽  
Work Environments ◽  
Task Orientation ◽  
Sound Exposure ◽  
Recorded Sound ◽  
Sound Levels ◽  
Sound Environment ◽  
Exposure Levels ◽  
Lower Background

The principle of this field study is an investigation of recorded sound levels in 24 classrooms and relations between sound level measures and aspects of children's rated annoyance, task orientation, and inattentiveness. The background sound-exposure levels were distributed within the interval of 33–42 dB(A)eq and the activity sound level exposure ranged between 47–68 dB(A)eq. The recorded levels must be considered as high for work environments where steady concentration and undisturbed communication is essential. Results do not support the hypothesis that lower background-sound level and fewer students per class would improve the sound environment by generating a lower activity noise or the hypothesis that higher sound levels should increase annoyance and inattentiveness as well as deteriorate task orientation ratings.

scholarly journals Underwater Sound Levels in Glacier Bay During Reduced Vessel Traffic Due to the COVID-19 Pandemic

2021 ◽  
Vol 8 ◽  
Author(s):  
Christine M. Gabriele ◽  
Dimitri W. Ponirakis ◽  
Holger Klinck
Keyword(s):  
Harbor Seal ◽  
Sound Level ◽  
Underwater Sound ◽  
Ecological Processes ◽  
Acoustic Environment ◽  
Glacier Bay ◽  
Cruise Ships ◽  
Sound Levels ◽  
Sound Environment ◽  
Vessel Noise

The global COVID-19 pandemic caused a sharp decline in vessel traffic in many areas around the world, including vessel-based tourism throughout Alaska, USA in 2020. Marine vessel traffic has long been known to affect the underwater acoustic environment with direct and indirect effects on marine ecological processes. Glacier Bay National Park in southeastern Alaska has monitored underwater sound since 2000. We used continuous, calibrated hydrophone recordings to examine 2020 ambient sound levels compared with previous years: 2018, the most recent year with data available, and 2016 for historical perspective. Park tourism occurs mainly in May–September. Overall, the number of vessel entries in Glacier Bay was 44–49% lower in 2020 (2020: n = 1,831; 2018: n = 3,599; 2016: n = 3,212) affecting all vessel classes, including the complete absence of cruise ships and only three tour vessel trips. In all years, we found clear seasonal and diurnal patterns in vessel generated noise, focused from 06:00 to 20:00 local time (LT) in the summer months. Broadband (17.8–8,910 Hz) sound levels in the 2020 Visitor Season were 2.7 dB lower than 2018 and 2.5 dB lower than 2016. Focusing on morning (06:00–09:00 LT) and afternoon (15:00–18:00 LT) time-blocks when tour vessels and cruise ships enter and exit Glacier Bay, median broadband sound levels were 3.3–5.1 dB lower in 2020 than prior years. At the 95th percentile levels, morning and afternoon peak times in 2020 were 6.3–9.0 dB quieter than previous years. A 3 dB decline in median sound level in the 125 Hz one-third octave band in 2020 reflects a change in medium and large vessel noise energy and/or harbor seal vocalizations. Our results suggest that all types of vessels had a role in the quieter underwater sound environment in 2020, with the combined acoustic footprint of tour vessels and cruise ships most evident in the decrease in the 95th percentile loudest sounds. This and other descriptions of the pandemic-induced quiet, and the gradual return to increased activity, can help inform efforts to improve existing methods to mitigate vessel noise impacts and maintain the ecological integrity of marine protected areas.

How can we reduce the environmental impact of marine seismic surveys?

2019 ◽  
Vol 59 (2) ◽  
pp. 909
Author(s):  
Andrew Long ◽  
Mickael Bastard ◽  
Endrias Asgedom ◽  
Jens Fredrik Wisløff ◽  
Magnus Christiansen
Keyword(s):  
Environmental Impact ◽  
Acoustic Pressure ◽  
Acoustic Energy ◽  
Seismic Sources ◽  
Exposure Level ◽  
Seismic Surveys ◽  
Sound Exposure ◽  
Environmental Controls ◽  
Marine Source ◽  
Marine Seismic

Marine seismic sources emit acoustic energy in the form of the seismic wavefield used for the remote sensing of subsurface impedance contrasts in the earth. The environmental impact of seismic sources is typically measured in terms of impulsive acoustic pressure (the sound pressure level, SPL) and the accumulated acoustic energy (the sound exposure level, SEL). We use global examples of the following marine source concepts to quantify the relative SPL and SEL in each scenario: • Large arrays of air guns activated simultaneously with no significant overlap in emitted acoustic pressure, • Small arrays of air guns activated simultaneously or in rapid succession with overlap in emitted acoustic pressure, • Individual air guns activated continuously with overlap in emitted acoustic pressure, and • Towed marine vibrators operated continuously. Continuous sources clearly have the lowest SPL and SEL. Examples from various basin settings are shown where benefits in data quality and survey efficiency may also complement the lower environmental impact. Another surprising geophysical outcome is that continuous sources with low SPL do not have compromised signal penetration to deep target depths compared to traditional large arrays of air guns activated simultaneously. These outcomes are relevant to how future marine seismic surveys might be designed to meet stricter environmental controls as well as presenting various new opportunities for how the surveys could be acquired more efficiently and processed.

The CarbonNet Project – a case study of the use of marine assessments and advisory panels for stakeholder assurance

2020 ◽  
Vol 60 (2) ◽  
pp. 486
Author(s):  
Victoria Mendes Da Costa
Keyword(s):  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Marine Species ◽  
Seismic Survey ◽  
Advisory Panel ◽  
Storage Site ◽  
Underwater Sound ◽  
Marine Habitat ◽  
Before And After ◽  
Marine Seismic

The CarbonNet project is investigating the feasibility of commercial-scale carbon capture and storage in Victoria. CarbonNet has identified a prospective storage site called Pelican, in the offshore Gippsland Basin in Bass Strait. CarbonNet undertook a 3D marine seismic survey (MSS) in 2018 as part of the appraisal program for Pelican. Environmental impacts and risks associated with the MSS were assessed in an Environment Plan accepted by Commonwealth and Victorian regulators. Underwater sound and its impact on the marine environment was a key issue raised by stakeholders. In response, CarbonNet put several initiatives in place to address concerns, including: undertaking marine habitat assessments before and after the MSS; and establishing an independent advisory panel to provide advice on the marine habitat assessments. The objectives of the habitat assessments were to confirm the abundance of key marine species before and after the MSS, and to determine whether any differences could be attributed to the MSS. To ensure that the habitat assessments were undertaken in a scientifically robust manner, an advisory panel was established consisting of representatives from regulatory agencies, academia and the fishing industry. This paper provides an overview of how CarbonNet used marine assessments and an advisory panel for stakeholder assurance.

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