Peak sound pressure and sound exposure level from underwater explosions in shallow water

2014 ◽  
Vol 136 (3) ◽  
pp. EL218-EL223 ◽  
Author(s):  
Alexander G. Soloway ◽  
Peter H. Dahl
Keyword(s):  
Shallow Water ◽  
Sound Pressure ◽  
Exposure Level ◽  
Underwater Explosions ◽  
Sound Exposure

Segmentwise Measurement of Helicopter Approach Noise with a Reduced Microphone Setup

2015 ◽  
Vol 60 (4) ◽  
pp. 1-18 ◽  
Author(s):  
W. F. J. Olsman ◽  
B. I. Schuchardt
Keyword(s):  
Statistical Analysis ◽  
Sound Pressure ◽  
Vertical Plane ◽  
Limited Area ◽  
Exposure Level ◽  
Geometric Accuracy ◽  
Large Area ◽  
Flight Tests ◽  
Landing Point ◽  
Sound Exposure

To measure the noise footprint of a helicopter approach procedure, microphones are usually distributed over a large area. In this paper, however, a method is utilized where the measurement of the noise footprint is conducted in parts by distributing the microphones over a limited area and executing the same approach procedure, while the position of the landing point is shifted. The flight tests are conducted with the EC135-ACT/FHS helicopter. Guidance to the pilots is provided by use of a “tunnel-in-the-sky” head down pilot display. Since the same flight procedure is executed multiple times, it is possible to conduct a statistical analysis on the accuracy and reproducibility of the approach procedure in terms of position, velocity, and generated noise. This statistical analysis shows that the geometric accuracy is on the order of 6 m in the horizontal plane and 12 m in the vertical plane. The variations in the measured sound exposure level from one approach to another are on the order of 3–7.5 dB(A). The approach procedure is also executed with excessive cyclic pilot control inputs to identify an upper limit of the extra noise generated by unsteady flight. However, these approaches are indistinguishable, in terms of the sound exposure level or sound pressure level, from the approaches with normal pilot control inputs.

scholarly journals Background noise analysis in urban airport surroundings of Brazilian cities, Congonhas Airport, São Paulo

2016 ◽  
Vol 50 (0) ◽  
Author(s):  
Fabio Scatolini ◽  
Cláudio Jorge Pinto Alves
Keyword(s):  
Traffic Control ◽  
Background Noise ◽  
Noise Analysis ◽  
Exposure Level ◽  
Noise Levels ◽  
Sound Exposure ◽  
Operational Characteristics ◽  
Data Compilation ◽  
Noise Measurements ◽  
Noise Data

ABSTRACT OBJECTIVE To perform a quantitative analysis of the background noise at Congonhas Airport surroundings based on large sampling and measurements with no interruption. METHODS Measuring sites were chosen from 62 and 72 DNL (day-night-level) noise contours, in urban sites compatible with residential use. Fifteen sites were monitored for at least 168 hours without interruption or seven consecutive days. Data compilation was based on cross-reference between noise measurements and air traffic control records, and results were validated by airport meteorological reports. Preliminary diagnoses were established using the standard NBR-13368. Background noise values were calculated based on the Sound Exposure Level (SEL). Statistic parameters were calculated in one-hour intervals. RESULTS Only four of the fifteen sites assessed presented aircraft operations as a clear cause for the noise annoyance. Even so, it is possible to detect background noise levels above regulation limits during periods of low airport activity or when it closes at night. CONCLUSIONS All the sites monitored showed background noise levels above regulation limits between 7:00 and 21:00. In the intervals between 6:00-6:59 and 21:00-22:59 the noise data, when analyzed with the current airport operational characteristics, still allow the development of additional mitigating measures.

Assessment of Barotrauma Injury and Cumulative Sound Exposure Level in Salmon After Exposure to Impulsive Sound

2012 ◽  
pp. 235-237 ◽  
Author(s):  
Michele B. Halvorsen ◽  
Brandon M. Casper ◽  
Thomas J. Carlson ◽  
Christa M. Woodley ◽  
Arthur N. Popper
Keyword(s):  
Exposure Level ◽  
Sound Exposure

Assessment of cumulative sound exposure level as criterion for exposure of fish to impulsive sound.

2009 ◽  
Vol 125 (4) ◽  
pp. 2488-2488
Author(s):  
Michele B. Halvorsen ◽  
Thomas Carlson ◽  
Arthur N. Popper
Keyword(s):  
Exposure Level ◽  
Sound Exposure

Empirical modelling for derived metrics as function of sound exposure level in marine pile driving

2018 ◽  
Vol 144 (3) ◽  
pp. 1809-1809
Author(s):  
Roel A. Müller ◽  
Michael A. Ainslie ◽  
Michele B. Halvorsen ◽  
Tristan Lippert
Keyword(s):  
Pile Driving ◽  
Exposure Level ◽  
Empirical Modelling ◽  
Sound Exposure

scholarly journals Effects of Background Sounds on Annoyance Reaction to Foreground Sounds in Psychoacoustic Experiments in the Laboratory: Limits and Consequences

2019 ◽  
Vol 9 (9) ◽  
pp. 1872 ◽  
Author(s):  
Armin Taghipour ◽  
Eduardo Pelizzari
Keyword(s):  
Sound Propagation ◽  
Background Level ◽  
Sound Level ◽  
Exposure Level ◽  
Block Designs ◽  
Sound Exposure ◽  
Balanced Incomplete Block Designs ◽  
Balanced Incomplete Block ◽  
Realistic Scenes ◽  
Noise Production

In a variety of applications, e.g., psychoacoustic experiments, virtual sound propagation demonstration, or synthesized noise production, noise samples are played back in laboratories. To simulate realistic scenes or to mask unwanted background sounds, it is sometimes preferable to add background ambient sounds to the noise. However, this can influence noise perception. It should be ensured that either background sounds do not affect, e.g., annoyance from foreground noise or that possible effects can be quantified. Two laboratory experiments are reported, in which effects of mixing background sounds to foreground helicopter samples were investigated. By means of partially balanced incomplete block designs, possible effects of three independent variables, i.e., helicopter’s sound exposure level, background type, and background sound pressure level were tested on the dependent variable annoyance, rated on the ICBEN 11-point numerical scale. The main predictor of annoyance was helicopter’s sound exposure level. Stimuli with eventful background sounds were found to be more annoying than those with less eventful background sounds. Furthermore, background type and level interacted significantly. For the major part of the background sound level range, increasing the background level was associated with increased or decreased annoyance for stimuli with eventful and less eventful background sounds, respectively.

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