Potential causes of increasing low‐frequency ocean noise levels.

2011 ◽  
Vol 129 (4) ◽  
pp. 2497-2497 ◽  
Author(s):  
Michael A. Ainslie
Keyword(s):  
Low Frequency ◽  
Noise Levels ◽  
Ocean Noise

scholarly journals A key to quieter seas: half of ship noise comes from 15% of the fleet

2018 ◽  
Author(s):  
Scott Veirs ◽  
Val Veirs ◽  
Rob Williams ◽  
Michael Jasny ◽  
Jason Wood
Keyword(s):  
Low Frequency ◽  
Noise Pollution ◽  
Marine Species ◽  
International Maritime Organization ◽  
Total Power ◽  
Underwater Noise ◽  
Noise Levels ◽  
Management Options ◽  
Ocean Noise ◽  
Wide Range

Underwater noise pollution from ships is a chronic, global stressor impacting a wide range of marine species. Ambient ocean noise levels nearly doubled each decade from 1963-2007 in low-frequency bands attributed to shipping, inspiring a pledge from the International Maritime Organization to reduce ship noise and a call from the International Whaling Commission for member nations to halve ship noise within a decade. Our analysis of data from 1,582 ships reveals that half of the total power radiated by a modern fleet comes from just 15% of the ships, namely those with source levels above 179 dB re 1 μPa @ 1 m. We present a range of management options for reducing ship noise efficiently, including incentive-based programs, without necessarily regulating the entire fleet.

scholarly journals A key to quieter seas: half of ship noise comes from 15% of the fleet

2018 ◽  
Author(s):  
Scott Veirs ◽  
Val Veirs ◽  
Rob Williams ◽  
Michael Jasny ◽  
Jason Wood
Keyword(s):  
Low Frequency ◽  
Noise Pollution ◽  
Marine Species ◽  
International Maritime Organization ◽  
Total Power ◽  
Underwater Noise ◽  
Noise Levels ◽  
Management Options ◽  
Ocean Noise ◽  
Wide Range

Underwater noise pollution from ships is a chronic, global stressor impacting a wide range of marine species. Ambient ocean noise levels nearly doubled each decade from 1963-2007 in low-frequency bands attributed to shipping, inspiring a pledge from the International Maritime Organization to reduce ship noise and a call from the International Whaling Commission for member nations to halve ship noise within a decade. Our analysis of data from 1,582 ships reveals that half of the total power radiated by a modern fleet comes from just 15% of the ships, namely those with source levels above 179 dB re 1 μPa @ 1 m. We present a range of management options for reducing ship noise efficiently, including incentive-based programs, without necessarily regulating the entire fleet.

Incubator Noise

PEDIATRICS ◽  
1975 ◽  
Vol 56 (4) ◽  
pp. 617-617
Author(s):  
Gōsta Blennow ◽  
Nils W. Svenningsen ◽  
Bengt Almquist
Keyword(s):  
Low Frequency ◽  
Sound Level ◽  
Noise Levels ◽  
Frequency Sound ◽  
Mechanical Noise ◽  
Sound Levels ◽  
Infant Incubator ◽  
Improved Model ◽  
Model C

Recently we reported results from studies of incubator noise levels.1 It was found that in certain types of incubators the noise was considerable, and attention was called to the sound level in the construction of new incubators. Recently we had the opportunity to study an improved model of Isolette Infant Incubator Model C-86 where the mechanical noise from the electrically powered motor has been partially eliminated. With this modification it has been possible to lower the low-frequency sound levels to a certain degree in comparison to the levels registered in our study.

Down‐slope enhancement models for low‐frequency ocean noise and propagation

1978 ◽  
Vol 64 (S1) ◽  
pp. S46-S46
Author(s):  
J. Northrop ◽  
R. A. Wagstaff
Keyword(s):  
Low Frequency ◽  
Ocean Noise

scholarly journals In search for the most optimal EEG method: A practical evaluation of a water-based electrode EEG system

2021 ◽  
Vol 5 ◽  
pp. 239821282110536
Author(s):  
Marta Topor ◽  
Bertram Opitz ◽  
Philip J. A. Dean
Keyword(s):  
Signal To Noise Ratio ◽  
Flanker Task ◽  
Low Frequency ◽  
Noise Levels ◽  
Slow Drift ◽  
Practical Evaluation ◽  
Beta Power ◽  
Water Based ◽  
High Beta ◽  
Frequency Power

The study assessed a mobile electroencephalography system with water-based electrodes for its applicability in cognitive and behavioural neuroscience. It was compared to a standard gel-based wired system. Electroencephalography was recorded on two occasions (first with gel-based, then water-based system) as participants completed the flanker task. Technical and practical considerations for the application of the water-based system are reported based on participant and experimenter experiences. Empirical comparisons focused on electroencephalography data noise levels, frequency power across four bands (theta, alpha, low beta and high beta) and event-related components (P300 and ERN). The water-based system registered more noise compared to the gel-based system which resulted in increased loss of data during artefact rejection. Signal-to-noise ratio was significantly lower for the water-based system in the parietal channels which affected the observed parietal beta power. It also led to a shift in topography of the maximal P300 activity from parietal to frontal regions. The water-based system may be prone to slow drift noise which may affect the reliability and consistency of low-frequency band analyses. Practical considerations for the use of water-based electrode electroencephalography systems are provided.

scholarly journals MobiLab – A Mobile Laboratory for On-Site Listening Experiments in Virtual Acoustic Environments

2019 ◽  
Vol 105 (5) ◽  
pp. 875-887
Author(s):  
Florian Pausch ◽  
Janina Fels
Keyword(s):  
Ambient Noise ◽  
Low Frequency ◽  
Mobile Laboratory ◽  
Noise Levels ◽  
Acoustic Parameters ◽  
Research Areas ◽  
Test Conditions ◽  
Acoustic Environments ◽  
Study Participants ◽  
Insulation Performance

Virtual acoustic environments have demonstrated their versatility for conducting studies in various research areas as they allow easy manipulations of experimental test conditions or simulated acoustic scenes, while providing expansion possibilities to related interdisciplinary and multimodal fields. Although the evolution of auditory and cognitive models is consistently pursued, listening experiments are still considered the gold standard, usually necessitating a large amount of resources, including travel expenses of study participants. In order to facilitate practical and efficient study execution, we therefore implemented a mobile hearing laboratory by acoustically optimising the interior of a caravan. All necessary technical facilities were integrated to perform listening experiments in virtual acoustic environments under controlled conditions directly on site, for example, in front of schools or senior residential centers. The design and construction of this laboratory are presented and evaluated based on insulation properties, selected room acoustic parameters, and interior ambient noise levels that are to be expected during operation at representative test sites. Limitations, particularly in low-frequency insulation performance, should provide incentives for further optimisations in similar future projects.

scholarly journals The Lombard effect in singing humpback whales: Source levels increase as ambient ocean noise levels increase

2020 ◽  
Vol 148 (2) ◽  
pp. 542-555 ◽  
Author(s):  
Regina A. Guazzo ◽  
Tyler A. Helble ◽  
Gabriela C. Alongi ◽  
Ian N. Durbach ◽  
Cameron R. Martin ◽  
...  
Keyword(s):  
Humpback Whales ◽  
Noise Levels ◽  
Lombard Effect ◽  
Ocean Noise

Recurrence Plot Analysis of HRV for Exposure to Low-Frequency Noise

2014 ◽  
Vol 1044-1045 ◽  
pp. 1251-1257 ◽  
Author(s):  
Shih Tsung Chen ◽  
Chia Yi Chou ◽  
Li Ho Tseng
Keyword(s):  
Low Frequency ◽  
Cardiovascular Responses ◽  
Recurrence Plot ◽  
Frequency Noise ◽  
Cardiovascular Activity ◽  
Low Frequency Noise ◽  
Noise Levels ◽  
Noise Condition ◽  
Plot Analysis ◽  
Recurrence Plot Analysis

Previous studies have indicated that the chronic effects of exposure to low-frequency noise causes annoyance. However, during the past two decades, most studies have employed questionnaires to characterize the effects of noise on psychosomatic responses. This study investigated cardiovascular activity changes in exposure to low-frequency noise for various noise intensities by using recurrence plot analysis of heart rate variability (HRV) estimation. The authors hypothesized that distinct noise intensities affect cardiovascular activity, which would be reflected in the HRV and recurrence quantification analysis (RQA) parameters. The test intensities of noises were no noise, 70-dBC, 80-dBC, and 90-dBC. Each noise level was sustained for 5 min, and the electrocardiogram (ECG) was recorded simultaneously. The cardiovascular responses were evaluated using RQA of the beat-to-beat (RR) intervals obtained from ECG signals. The results showed that the mean RR interval variability and mean blood pressure did not substantially change relative to the noise levels. However, the length of the longest diagonal line (Lmax) of the RQA of the background noise (no noise) condition was significantly lower than the 70-dBC, 80-dBC, and 90-dBC noise levels. The laminarity showed significant changes in the noise levels of various intensities. In conclusion, the RQA-based measures appear to be an effective tool for exposure to low-frequency noise, even in short-term HRV time series.

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