Effect of Rain upon Underwater Noise Levels

1955 ◽  
Vol 27 (2) ◽  
pp. 378-379 ◽  
Author(s):  
T. E. Heindsmann ◽  
R. H. Smith ◽  
A. D. Arneson
Keyword(s):  
Underwater Noise ◽  
Noise Levels

scholarly journals Measurement of small vessel machinery vibration induced acoustic signature levels

2019 ◽  
Vol 16 (2) ◽  
pp. 87-98 ◽  
Author(s):  
GVV Pavan Kumar ◽  
V V S Prasad ◽  
B H Nagesh
Keyword(s):  
Pressure Fluctuations ◽  
Response Spectra ◽  
Underwater Sound ◽  
Underwater Noise ◽  
Noise Levels ◽  
Small Vessels ◽  
Performance Point ◽  
Engine Room ◽  
Airborne Noise ◽  
Main Engine

Ship vibrations, airborne and underwater noise levels have always been a challenging topic from a performance point of view in ship design, building and operation. The measurement shall help in monitoring the self-noise and the technical state of their machinery mechanism. The vibration levels on the main engine and auxiliary Genset foundation, airborne noise levels of the engine room and underwater self-noise levels of a small mechanized fishing trawler was measured at the jetty in idling condition.  The vibration levels on the foundation measured the average value of 0.207 mm/s for the main engine and 1.36 mm/s for auxiliary Genset. The airborne noise levels measured 99 dB (A) in the engine room. The peak underwater sound pressure levels measured 162 dB re 1µPa. The response spectra indicate the peak vibration and noise levels in the lower frequency region <1.2 kHz. The machinery excitation forces transferred to the hull surface as pressure fluctuations which generated the airborne and underwater noise levels. Though the measurement limited to jetty conditions, detailed analysis can be useful for detection, classification, and tracking of small vessels.

Detection of long term trends in underwater noise levels

2016 ◽  
Vol 140 (4) ◽  
pp. 3024-3024
Author(s):  
Claire F. Powell ◽  
Nathan D. Merchant
Keyword(s):  
Underwater Noise ◽  
Noise Levels ◽  
Long Term Trends

scholarly journals Soundscape and ambient noise levels of the Arctic waters around Greenland

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael Ladegaard ◽  
Jamie Macauley ◽  
Malene Simon ◽  
Kristin L. Laidre ◽  
Aleksandrina Mitseva ◽  
...  
Keyword(s):  
Ambient Noise ◽  
Anthropogenic Activities ◽  
Open Water ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Underwater Noise ◽  
Noise Levels ◽  
Greenland Sea ◽  
Mammal Species ◽  
Seismic Surveys

AbstractA longer Arctic open water season is expected to increase underwater noise levels due to anthropogenic activities such as shipping, seismic surveys, sonar, and construction. Many Arctic marine mammal species depend on sound for communication, navigation, and foraging, therefore quantifying underwater noise levels is critical for documenting change and providing input to management and legislation. Here we present long-term underwater sound recordings from 26 deployments around Greenland from 2011 to 2020. Ambient noise was analysed in third octave and decade bands and further investigated using generic detectors searching for tonal and transient sounds. Ambient noise levels partly overlap with previous Arctic observations, however we report much lower noise levels than previously documented, specifically for Melville Bay and the Greenland Sea. Consistent seasonal noise patterns occur in Melville Bay, Baffin Bay and Greenland Sea, with noise levels peaking in late summer and autumn correlating with open water periods and seismic surveys. These three regions also had similar tonal detection patterns that peaked in May/June, likely due to bearded seal vocalisations. Biological activity was more readily identified using detectors rather than band levels. We encourage additional research to quantify proportional noise contributions from geophysical, biological, and anthropogenic sources in Arctic waters.

Assessment of the proportion of anthropogenic underwater noise levels in passive acoustic monitoring

2017 ◽  
Vol 142 (4) ◽  
pp. 2685-2685
Author(s):  
Mirko Mustonen ◽  
Aleksander Klauson ◽  
Mihkel Tommingas ◽  
Julia Berdnikova
Keyword(s):  
Acoustic Monitoring ◽  
Underwater Noise ◽  
Noise Levels ◽  
Passive Acoustic Monitoring ◽  
Passive Acoustic

Underwater noise levels in Indian waters off the coast of Mormugao Port

2019 ◽  
Vol 14 (1) ◽  
pp. 48-58
Author(s):  
G. V. V. Pavan Kumar ◽  
V. V. S. Prasad ◽  
U. S. Ramesh
Keyword(s):  
Underwater Noise ◽  
Noise Levels ◽  
Indian Waters

Underwater noise and Arctic marine mammals: review and policy recommendations

2020 ◽  
Vol 28 (4) ◽  
pp. 438-448 ◽  
Author(s):  
William D. Halliday ◽  
Matthew K. Pine ◽  
Stephen J. Insley
Keyword(s):  
Sea Ice ◽  
Marine Mammals ◽  
Anthropogenic Activities ◽  
The Arctic ◽  
Auditory Masking ◽  
Underwater Noise ◽  
Noise Levels ◽  
Marine Animals ◽  
Sound Levels ◽  
Ambient Sound

Underwater noise is an important issue globally. Underwater noise can cause auditory masking, behavioural disturbance, hearing damage, and even death for marine animals. While underwater noise levels have been increasing in nonpolar regions, noise levels are thought to be much lower in the Arctic where the presence of sea ice limits anthropogenic activities. However, climate change is causing sea ice to decrease, which is allowing for increased access for noisy anthropogenic activities. Underwater noise may have more severe impacts in the Arctic compared with nonpolar regions due to a combination of lower ambient sound levels and increased sensitivity of Arctic marine animals to underwater noise. Here, we review ambient sound levels in the Arctic, as well as the reactions of Arctic and sub-Arctic marine mammals to underwater noise. We then relate what is known about underwater noise in the Arctic to policies and management solutions for underwater noise and discuss whether Arctic-specific policies are necessary.

scholarly journals First observations of anthropogenic underwater noise in a large multi-use lake

2016 ◽  
Author(s):  
Marta Bolgan ◽  
Emilia Chorazyczewska ◽  
Ian J. Winfield ◽  
Antonio Codarin ◽  
Joanne O'Brien ◽  
...  
Keyword(s):  
Fish Community ◽  
Noise Pollution ◽  
Anthropogenic Noise ◽  
Underwater Noise ◽  
Noise Levels ◽  
Potential Threat ◽  
Spectral Content ◽  
Freshwater Organisms ◽  
Passive Acoustic ◽  
Inland Water Bodies

<p>Over the last fifty years, anthropogenic noise has increased dramatically in aquatic environments and is now recognised as a chronic form of pollution in coastal waters. However, this form of pollution has been largely neglected in inland water bodies. To date, very few studies have investigated the noise spectra in freshwater environments and at present no legislation exists to protect freshwater organisms from anthropogenic noise. The present study represents the first assessment of anthropogenic noise pollution in<strong> </strong>a large multi-use lake<strong> </strong>by characterising noise levels of the main ferry landings of the lake of Windermere, UK using Passive Acoustic Monitoring (PAM). During November 2014, acoustic samples (10 min long) were collected from such areas using a calibrated omni-directional hydrophone and their spectral content was analysed in 1/3 octave bands (dB re 1 µPa). Results indicate that the current noise levels in Windermere warrant further investigation as a potential threat to the fish community which occurs in this already delicate and pressured habitat. Based on results obtained, it is recommended that further studies focus on a wider geographical and temporal range in order to start to fill the knowledge and legislative gaps regarding anthropogenic noise monitoring in fresh waters. </p>

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