Ecological Risk Assessment of Underwater Sounds from Dredging Operations

There is an increasing international focus to understand and quantify the potential ecological risks of low-frequency underwater sounds produced from anthropogenic activities (e.g., commercial shipping, dredging, construction, and offshore energy production). For dredge operations, a risk-based approach has been proposed for identifying,...

Diving apart together Call propagation in diving long-finned pilot whales

International Airgun Modeling Workshop: Validation of Source Signature and Sound Propagation Models - Dublin (Ireland), July 16, 2016 - Problem Description

Computer models can be used to predict the sound field near an airgun or airgun array. The accuracy of such predictions can be assessed either by a process of verification (comparison with alternative theoretical solution to the same computational problem) or by validation (comparison with measurement). A set of verification test problems is...

Summary report panel 1: The need for protocols and standards in research on underwater noise impacts on marine life

As concern about anthropogenic noise and its impacts on marine fauna is increasing around the globe, data are being compared across populations, species, noise sources, geographic regions, and time. However, much of the raw and processed data are not comparable due to differences in measurement methodology, analysis and reporting, and a lack of...

WODA technical guidance on underwater sound from dredging

The World Organization of Dredging Associations (WODA) has identified underwater sound as an environmental issue that needs further consideration. A WODA Expert Group on Underwater Sound (WEGUS) prepared a guidance paper in 2013 on dredging sound, including a summary of potential impacts on aquatic biota and advice on underwater sound monitoring...

Offshore dredger sounds: Source levels, sound maps, and risk assessment

The underwater sound produced during construction of the Port of Rotterdam harbor extension (Maasvlakte 2) was measured, with emphasis on the contribution of the trailing suction hopper dredgers during their various activities: dredging, transport, and discharge of sediment. Measured source levels of the dredgers, estimated source levels of...

Underwater noise measurements in the North Sea in and near the Princess Amalia Wind Farm in operation

Effect of pile-driving sounds on the survival of larval fish

Concern exists about the potential effects of pile-driving sounds on fish, but evidence is limited, especially for fish larvae. A device was developed to expose larvae to accurately reproduced pile-driving sounds. Controlled exposure experiments were carried out to examine the lethal effects in common sole larvae. No significant effects were...

Underwater sound radiation from subsea factories

In the oil & gas industry there is a trend towards more subsea activities such as the processing of the Oil and Gas in so-called 'subsea factories'. Regulations aimed at managing the impact of underwater sound on marine life are being put in place by different nations. Many offshore operations require an assessment of the potential impact of...

Dose-response relationships for the onset of avoidance of sonar by free-ranging killer whales

Eight experimentally controlled exposures to 1−2 kHz or 6−7 kHz sonar signals were conducted with four killer whale groups. The source level and proximity of the source were increased during each exposure in order to reveal response thresholds. Detailed inspection of movements during each exposure session revealed sustained changes in speed and...

The effect of the number of aircraft noise events on sleep quality

Background Both the WHO and the EC recommend the use of Lnight as the primary indicator for sleep disturbance. Still, a key question for noise policy is whether the prediction of sleep quality could be improved by taking the number of events into account in addition to Lnight. Objectives The current paper investigates the association between...

Low sound level source path contribution on a HVAC

For compliance test purposes, the noise level of a HVAC is usually measured with a pressure microphone positioned at a certain distance. This measurement is normally performed in an anechoic room. However, this method doesn't provide the engineer any insight on what noise sources do contribute to the overall noise level measured. A new...

A numerical technique to design blast noise mitigation measures

Large weapons, such as armor, artillery or demolitions, create a high-energy blast wave. It has a low frequency content, typically between 15 and 125 Hz, and can propagate over large distances. As a result it is a relative important cause for annoyance. Mitigation measures need to be close to the source for best effectiveness, but due to the...

The influence of signal parameters on the sound source localization ability of a harbor porpoise (Phocoena phocoena)

It is unclear how well harbor porpoises can locate sound sources, and thus can locate acoustic alarms on gillnets. Therefore the ability of a porpoise to determine the location of a sound source was determined. The animal was trained to indicate the active one of 16 transducers in a 16-m -diam circle around a central listening station. The...

Caustic envelopes and cusp coordinates due to the reflection of a spherical wave from a layered sediment

A compilation of analytical formulas is presented, describing ray properties of a family of sediment sound speed profiles. The profiles are described as "generalized power law" profiles because they are generalizations of a similar family of simpler power law profiles considered in earlier work [M. A. Ainslie, J. Acoust. Soc. Am. 96, 2506–2515 ...

Reduction of the performance of a noise screen due to screen-induced wind-speed gradients: Numerical computations and wind-tunnel experiments

Downwind sound propagation over a noise screen is investigated by numerical computations and scale model experiments in a wind tunnel. For the computations, the parabolic equation method is used, with a range-dependent sound-speed profile based on wind-speed profiles measured in the wind tunnel and wind-speed profiles computed with computational...

Experimental validation of the twins prediction program for rolling noise. Pt.1: description of the model and method

The C163 Expert Committee of the European Rail Research Institute (ERRI) concerned with Railway Noise, has been developing theoretical models for the generation of wheel/rail rolling noise. These models have been brought together into a software package, called TWINS ("Track-Wheel Interaction Noise Software"). This is intended as a tool with...

Ons oor en het geluid om ons heen: vragen en antwoorden op een rij gezet door TNO