The hydro-acoustic noise radiating from underwater tunnels during vehicle passage may be harmful to aquatic fauna, and this is a particular concern for endangered species. Therefore, the effects of underwater noise radiation and propagation on aquatic biodiversity must be investigated. In this study, the dynamic response of the sediment and tunnel structure in the Yangtze River in China was explored by conducting a field test, and the associated noise radiation from the tunnel was recorded and investigated. A three-dimensional numerical model was then developed to simulate the vibration of the tunnel-sediment coupling system induced by random traffic-flow models. Next, a modal acoustic transfer vector-based method was used to predict underwater noise radiation by use of a three-dimensional finite-element acoustic model. Finally, the accuracy of the simulated results was verified by comparison with measurements. The results showed that the noise radiation induced by passing vehicles was approximately 14 dB greater than the background noise, with a main frequency range of 12–25 Hz. The random traffic-flow model had obvious influence of the simulated noise level above 20 Hz. Vehicle-induced underwater noise may thus have a direct effect on fish species that can perceive low-frequency sound pressure. The proposed method can be used for further investigation of methods to reduce the effect of underwater noise on aquatic fauna, especially endangered species.

We measured spatial and temporal patterns of ambient noise in dynamic, relatively pristine Arctic marine habitats and evaluate the contributions of environmental and human noise sources. Long-term acoustic recorders were deployed around St. Lawrence Island and the Bering Strait region within key feeding and migratory corridors for protected species that are inherently important to Native Alaskan cultures. Over 3000 h of data from 14 recorders at nine sites were obtained from October 2014 to June 2017. Spatial and temporal ambient noise patterns were quantified with percentile statistics in 1/3rd-octave bands (0.02–8 kHz). Ice presence strongly influenced ambient noise by influencing the physical environment and presence of marine mammals. High variability in noise was observed within and between sites, largely as a function of ice presence and associated factors. Acute contributions of biological and anthropogenic sources to local ambient noise are compared to monthly averages, demonstrating how they influence Arctic soundscapes.

Underwater noise pollution from impulsive sources (e.g. explosions, seismic airguns, percussive pile driving) can affect marine fauna through mortality, physical injury, auditory damage, physiological stress, acoustic masking, and behavioural responses. Given the potential for large-scale impact on marine ecosystems, some countries are now monitoring impulsive noise activity, coordinated internationally through Regional Seas Conventions. Here, we assess impulsive noise activity in the Northeast Atlantic reported during 2015–2017 to the first international impulsive noise register (INR), established in 2016 under the OSPAR Convention. Seismic airgun surveys were the dominant noise source (67%-83% of annual activity) and declined by 38% during 2015–2017. Reported pile driving activity increased 46%. Explosions and sonar/acoustic deterrent devices both had overall increases in reported activity. Some increases were attributable to more comprehensive reporting in later years. We discuss utilising the INR for risk assessment, target setting, and forward planning, and the implementation of similar systems in other regions.

Impulsive sounds generated during seismic surveys have elicited behavioral responses in marine mammals and could cause hearing impairment or injury. Mitigating exposure to seismic sound often relies on real-time marine mammal detection. Detection performance is influenced by detection method, environmental conditions, and observer experience. We conducted a field comparison of real-time detections made by marine mammal observers (MMOs), a rotating infrared (IR) camera, and via passive acoustic monitoring (PAM). Data were collected from a 38 m research vessel offshore Atlantic Canada. Our results indicate that overall detection rates increase when complementary methods are used. MMOs and PAM are likely the most effective combination during high seas and precipitation. PAM and IR can be used in darkness. In good visibility, MMOs with IR or PAM should increase detections. Our results illustrate the importance of addressing false positive IR detections, matching system capabilities to sea conditions/species of interest, and employing experienced observers.

As part of the Deepwater Horizon Oil Spill Natural Resource Damage Assessment in the Gulf of Mexico, we conducted a large passive acoustic survey across the eastern Gulf continental shelf edge to assess impacts to sperm whale population. In the months immediately after the spill, sperm whale occurrence was significantly higher in areas closest to the spill. Over the following seasons in 2010–2011, we documented cyclical patterns of decreased and increased occurrence suggesting that this population exhibits a seasonal occurrence pattern in the region, with seasonal movements to other regions, and not likely directly influenced by the oil spill. Unfortunately, a lack of adequately scaled, pre-spill data on sperm whales, along with limitations on the survey duration constrain our ability to infer spill-related changes in sperm whale occurrence. However, our study establishes post-disaster baseline data for continued monitoring, and an expanded study design could provide a model for continued monitoring.

Acoustic data was collected across 15 sites distributed through the coastal area of Rio de Janeiro, Brazil, encompassing regions of different natural characteristics. Noise levels and the acoustic complexity index were calculated. Quantity and composition of anthropogenic sound sources varied across recording sites, with at least one type of sound source being registered in each location. A cluster analysis using third-octave levels from eight frequency bands divided recording sites into two groups, one considered as impacted by anthropogenic noise and the other as less-impacted. The noisiest recording locations were those with higher numbers of anthropogenic sound sources, specifically large ships. It was evidenced that anthropogenic noise affects not only noise levels, but also low-frequency acoustic complexity, which decreased in the presence of vessel traffic. The constant noise input of human activities tended to mask natural variability in the soundscape at lower frequencies.

PURPOSE OF REVIEW: The present review aims to highlight the noise effects on the patients’ well-being and by inference on their recovery, during their hospitalization, and also the effectiveness of applied interventions to reduce noise in the health care environment. RECENT FINDINGS: Key findings reported in relevant studies and conducted during the last 4 years are as follows: (a) noise continues to be above guideline values in health care facilities; (b) noise can disturb the sleep of the patients, can affect their rest and the communication between patients/staff/visitors, and finally can affect the staff effectiveness; (c) interventions to reduce the noise are promising but not well proven; and (d) the derived conclusions about the relationship between noise and the healing process are made indirectly and not by measurable patients’ physical parameters. The pathways that theoretically connect noise and the healing of the patients are numerous and still unclear. An extensively examined pathway infers that noise can disturb sleep and thus may prevent the patient’s recovery. Other pathways that relate noise to the recovery of the inpatients remain unknown, such as the aggravation/degradation of measureable physical parameters or the re-hospitalization due to noise, or the effect of the low-frequency noise. A protocol to conduct noise monitoring is required, as well as validated questionnaires, to examine the inpatient’s subjective perceptions for their acoustic environment. This may lead to comparable results among the relevant studies and hence to robust interventions for the improvement of the noise environment for hospitalized patients.

Measurements of underwater noise radiated under ship normal operations are presented. The acoustic data, from the cabled ocean observatory, are analyzed under each identified ship passage, which was obtained by the Automatic Identification System. Under each passage, sound pressure level is calculated to observe local noise variations due to shipping noise. This paper emphasizes the study of noise variations at the observatory, presents the noise measurements under identified ship passages in the last several years, and provides references for predictive models of underwater noise pollution from commercial ship traffic. From the passages of one ship to the passages of 26 ships, the measurements reveal similar variation patterns when the ships traveled at similar courses, but different patterns when they traveled at different courses. When evaluating the noise variations due to ship traffics, it is important to consider the shipping noise propagation as well as ship movement.

The Ria Formosa is a sheltered large coastal lagoon located on the Atlantic South Coast of Portugal, that has been classified as a natural park since 1987. The lagoon hosts a diverse and abundant fish community and other species of commercial importance. Several economical activities are supported by shipping, and as such, vessel traffic within the Ria Formosa lagoon is very intense at some locations during particular seasons of the year, creating high levels of underwater noise. Recently, strong efforts are being made to turn the main inlet of the lagoon, the Faro-Olhão Inlet, a testing site for small scale tidal stream turbines, which will bring an additional source of underwater noise. Underwater noise can be one of a number of factors causing habitat degradation, as it can perturb fish behavior and cause physiological damage. Therefore, in order to comply with underwater noise pollution regulations, tidal energy technology developers are very interested in minimising the introduction of acoustic energy in the environment during the operation of their devices. Under the scope of project SCORE, which involved the deployment and operation of a floating tidal energy converter, this paper presents and discusses the first baseline noise monitoring performed at Ria Formosa. The acoustic data were collected in two occasions over several days, one in the winter and the other in the summer, in 2017. The obtained analysis results highlight the potential impact of the intense boat traffic in Ria Formosa, and the wide range of sound levels introduced in that ecosystem, and the high diurnal and seasonal variability.

The seabed off North West Europe contains much unexploded ordnance (UXO), posing a hazard to offshore developments such as windfarms. The typical removal method is through high-order detonation of a donor charge placed adjacent to the UXO. This method poses a risk of injury or death to marine mammals and other fauna from the high sound levels produced. This paper describes a controlled field experiment to compare the sound produced by high-order detonations with a low-order disposal method called deflagration, which uses a shaped charge of modest size, is less energetic, and offers reduced environmental impact from lower acoustic output. The results demonstrate a substantial reduction over high order detonation, with the peak sound pressure level and sound exposure level being more than 20 dB lower for the deflagration, and with the acoustic output depending only on the size of the shaped charge (rather than the size of the UXO).