Investigation of nonlinear propagation effects on sound from supersonic bullets

ISO standard 17201-4 is a calculation method for sound levels generated by supersonic bullets. The standard takes into account nonlinear propagation effects, including broadening of a sound pulse with increasing propagation distance. Two elements of the ISO method are investigated in this paper: i) the accuracy for various Mach numbers, and ii)...

Effect of pile-driving sounds on the survival of larval fish (abstract)

In view of the rapid extension of offshore wind farms, there is an urgent need to improve our knowledge on possible adverse effects of underwater sound generated by pile-driving. Mortality and injuries have been observed in fish exposed to loud impulse sounds, but knowledge on the sound levels at which (sub-)lethal effects occur is limited,...

The European Marine Strategy - noise monitoring in European marine waters (abstract)

The European Marine Strategy Framework Directive requires European member states to develop strategies for their marine waters that should lead to programmes of measures that achieve or maintain Good Environmental Status (GES) in all European seas by 2020. As an essential step towards reaching GES, member states should establish monitoring...

Offshore dredger sound: Source levels, sound maps and risk assessment (abstract)

The Port of Rotterdam is expanding to meet the growing demand to accommodate large cargo vessels. One of the licensing conditions was the monitoring of the underwater sound produced during its construction, with an emphasis on the establishment of acoustic source levels of the Trailing Suction Hopper Dredgers during their various activities:...

The WODA guidance paper on underwater sound from dredging (abstract)

The World Organisation of Dredging Associations (WODA) has identified underwater sound as an environmental issue that needs further consideration. A WODA Expert Group on Underwater Sound (WEGUS) was established to provide a guidance paper on dredging sound, impact on aquatic biota and advice on underwater sound monitoring procedures. The paper...

A Hybrid Finite Element/Helmholtz-Kirchhoff-Integral Model for Shooting Range Sound Prediction

National legislation enforces a limit on the Sound Levels of outdoor military shooting ranges observed in nearby residential areas. These restrictions directly influence the number of shots that may be fired at a specific shooting range, which may conflict with the required/ scheduled training capacity for that specific range. If desired, sound...

Annoyance caused by low frequency sounds: Spectral and temporal effects

The objective of the present laboratory studies was to enable refinements of the current rating procedure for low frequency sounds. To increase our insight into a relevant spectral issue, groups of adjacent frequency bands around 40, 50, and 63 Hz were presented at various sound level combinations. It was concluded that an energy-based summation...

An acoustical model based monitoring network

In this paper the approach for an acoustical model based monitoring network is demonstrated. This network is capable of reconstructing a noise map, based on the combination of measured sound levels and an acoustic model of the area. By pre-calculating the sound attenuation within the network the noise map can be shown in real-time. The...

The acoustic source strength of high-energy blast waves: combining measurements and a non-linear model

In the densely populated area of the Netherlands, the objective of the Netherlands Ministry of Defence is to find an optimal balance between military training and the impact on the surrounding civilian community. A special case concerns large weapons, such as artillery or demolitions, which create high-energy blast waves. These waves have a low...

Sound propagation in cities

A new engineering model for sound propagation in cities is presented. The model is based on numerical and experimental studies of sound propagation between street canyons. Multiple reflections in the source canyon and the receiver canyon are taken into account in an efficient way, while weak reflections by distant buildings involving multiple...

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...

Mitigation of low-frequency groundnoise from runways

With the extra runway at Amsterdam Schiphol Airport, introduced in 2003, the noise nuisance for local residents increased due to increased groundnoise. In a case study the effect of enhanced ground absorption on the propagation of low-frequency noise from aircraft ground operations, e.g. departing aircraft, has been investigated. The study was...

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...

Some aspects to improve sound insulation prediction models for lightweight elements

The best approach to include lightweight building elements in prediction models for airborne and impact sound insulation between rooms, as in EN 12354, is not yet completely clear. Two aspects are at least of importance, i.e. to derive the sound reduction index R for lightweight elements for resonant vibrations only and the appropriate method to...

Relationship between exposure to multiple noise sources and noise annoyance

Relationships between exposure to noise [metric: day-night level (DNL) or day-evening-night level (DENL)] from a single source (aircraft, road traffic, or railways) and annoyance based on a large international dataset have been published earlier. Also for stationary sources relationships have been assessed. Here the annoyance equivalents model...

A- and C-weighted sound levels as predictors of the annoyance caused by shooting sounds, for various facade attenuation types

In a previous study on the annoyance caused by a great variety of shooting sounds [J. Acoust. Soc. Am. 109, 244-253 (2001)], it was shown that the annoyance, as rated indoors with the windows closed, could be adequately predicted from the outdoor A-weighted and C-weighted sound-exposure levels [ASEL (L(AE)) and CSEL (L(CE))] of the impulse...

A-weighted equivalent sound level as a predictor of the annoyance caused by road traffic consisting of various proportions of light and heavy vehicles

A laboratory study was conducted to examine the relationship between noise annoyance and the proportion of heavy vehicles in a mixture of trucks and passenger cars. Twenty normal-hearing subjects were asked to judge the annoyance caused by the sounds from a continuous stream of vehicles, assuming they were exposed to it at home on a regular...

Roughness on Dutch railway wheels and rails

Surface roughness on 150 railway wheels and on the rails of 30 sites in the Netherlands have been measured. Block braked wheels were found to show higher roughnesses than the rail at any site. The smoothest rail is 8 dB smoother than the smoothest wheel. It was concluded that in reducing railway rolling noise NS must start to find ways to lower...