Some Periodic Variations in Low‐Frequency Acoustic Ambient Noise Levels in the Ocean

Gordon M. Wenz

doi:10.1121/1.1908406

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

Acta Acustica united with Acustica ◽

10.3813/aaa.919367 ◽

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.

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Periodic Variations in Low‐Frequency Underwater Ambient Noise Levels

The Journal of the Acoustical Society of America ◽

10.1121/1.1936431 ◽

1960 ◽

Vol 32 (7) ◽

pp. 915-915

Author(s):

Gordon M. Wenz

Keyword(s):

Ambient Noise ◽

Low Frequency ◽

Noise Levels

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Effect of COVID-19 spring lockdown on low-frequency ambient noise levels along the Brittany coast

The Journal of the Acoustical Society of America ◽

10.1121/10.0004600 ◽

2021 ◽

Vol 149 (4) ◽

pp. A87-A87

Author(s):

Delphine Mathias ◽

Julien Bonnel ◽

Laurent Chauvaud

Keyword(s):

Ambient Noise ◽

Low Frequency ◽

Noise Levels

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Large Vessel Activity and Low-Frequency Underwater Sound Benchmarks in United States Waters

Frontiers in Marine Science ◽

10.3389/fmars.2021.669528 ◽

2021 ◽

Vol 8 ◽

Author(s):

Samara M. Haver ◽

Jeffrey D. Adams ◽

Leila T. Hatch ◽

Sofie M. Van Parijs ◽

Robert P. Dziak ◽

...

Keyword(s):

Gulf Of Mexico ◽

Ambient Noise ◽

Low Frequency ◽

Underwater Sound ◽

Noise Levels ◽

Passive Acoustic Monitoring ◽

Sound Levels ◽

Alaskan Arctic ◽

Passive Acoustic ◽

The U.S

Chronic low-frequency noise from commercial shipping is a worldwide threat to marine animals that rely on sound for essential life functions. Although the U.S. National Oceanic and Atmospheric Administration recognizes the potential negative impacts of shipping noise in marine environments, there are currently no standard metrics to monitor and quantify shipping noise in U.S. marine waters. However, one-third octave band acoustic measurements centered at 63 and 125 Hz are used as international (European Union Marine Strategy Framework Directive) indicators for underwater ambient noise levels driven by shipping activity. We apply these metrics to passive acoustic monitoring data collected over 20 months in 2016–2017 at five dispersed sites throughout the U.S. Exclusive Economic Zone: Alaskan Arctic, Hawaii, Gulf of Mexico, Northeast Canyons and Seamounts Marine National Monument (Northwest Atlantic), and Cordell Bank National Marine Sanctuary (Northeast Pacific). To verify the relationship between shipping activity and underwater sound levels, vessel movement data from the Automatic Identification System (AIS) were paired to each passive acoustic monitoring site. Daily average sound levels were consistently near to or higher than 100 dB re 1 μPa in both the 63 and 125 Hz one-third octave bands at sites with high levels of shipping traffic (Gulf of Mexico, Northeast Canyons and Seamounts, and Cordell Bank). Where cargo vessels were less common (the Arctic and Hawaii), daily average sound levels were comparatively lower. Specifically, sound levels were ∼20 dB lower year-round in Hawaii and ∼10-20 dB lower in the Alaskan Arctic, depending on the season. Although these band-level measurements can only generally facilitate differentiation of sound sources, these results demonstrate that international acoustic indicators of commercial shipping can be applied to data collected in U.S. waters as a unified metric to approximate the influence of shipping as a driver of ambient noise levels, provide critical information to managers and policy makers about the status of marine environments, and to identify places and times for more detailed investigation regarding environmental impacts.

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