Noise map validation by continuous noise monitoring

2011 ◽  
Vol 72 (8) ◽  
pp. 582-589 ◽  
Author(s):  
Piotr Mioduszewski ◽  
Jerzy A. Ejsmont ◽  
Jan Grabowski ◽  
Daniel Karpiński
2021 ◽  
Vol 22 ◽  
pp. 103929
Author(s):  
Jie Wen ◽  
Yuanhao Shi ◽  
Jianfang Jia ◽  
Jianchao Zeng

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mariarosaria Falanga ◽  
Paola Cusano ◽  
Enza De Lauro ◽  
Simona Petrosino

AbstractIn this paper, we analyse the seismic noise at Ischia Island (Italy) with the objective of detecting the hydrothermal source signals taking advantage of the Covid-19 quiescence due to lockdown (strong reduction of anthropogenic noise). We compare the characteristics of the background noise in pre-, during and post-lockdown in terms of spectral content, energy release (RMS) and statistical moments. The continuous noise is decomposed into two independent signals in the 1−2 Hz and 2−4 Hz frequency bands, becoming sharpened around 1 Hz and 3 Hz respectively in lockdown. We propose a conceptual model according to which a dendritic system of fluid-permeated fractures plays as neighbour closed organ pipes, for which the fundamental mode provides the persistent whisper and the first higher mode is activated in concomitance with energy increases. By assuming reasonable values for the sound speed in low vapor–liquid mass fraction for a two-phase fluid and considering temperatures and pressures of the shallow aquifer fed by sea, meteoric and deep hydrothermal fluids, we estimate pipe lengths in the range 200–300 m. In this scheme, Ischia organ-like system can play both continuous whisper and transients, depending on the energy variations sourced by pressure fluctuations in the hydrothermal fluids.


Author(s):  
Sagar Ravi Bhavsar ◽  
Andrei Vatavu ◽  
Timo Rehfeld ◽  
Gunther Krehl

1986 ◽  
Vol 63 (2) ◽  
pp. 599-616
Author(s):  
Malcolm D. Arnoult ◽  
Lynne G. Gillfillan ◽  
James W. Voorhees

College students were exposed by means of headphones to two kinds of aircraft noise (helicopter and jet) at three levels of loudness (60, 70, and 80 dB) while engaging in two tests of intelligibility and 12 cognitive tasks. In addition, the annoyingness of the noise was rated on a seven-point scale for each source/loudness combination in each task. Individual-differences measures (embedded figures, locus-of-control, and test anxiety) were also obtained. No performance difference related to noise was obtained in any of the cognitive tasks, and using the individual-difference measures as co-variates made no difference. In a second experiment a limited set of five modified cognitive tasks was used, again without producing any significant results. Finally, a third experiment utilized four cognitive tasks, a perceptual-motor task (Rotary Tracking) and intermittent rather than continuous noise, and yielded the same results. It was concluded that the failure to find performance differences on the cognitive tasks was probably due to the fact that concern for the welfare of the subjects limited the stimuli to loudness levels that were too low to be effective.


Author(s):  
Andrii Shelestov ◽  
Hanna Yailymova ◽  
Bohdan Yailymov ◽  
Artem Chyrkov
Keyword(s):  

1975 ◽  
Vol 19 (3) ◽  
pp. 301-304
Author(s):  
Ann E. Martin

The present study was conducted to investigate the effects of environmental conditions on visual workload. The environmental variables used were temperature, studied at levels of 45°F., WBGT, and 95°F., WBGT; and noise, studied at 83 dBA intermittent noise and 93 dBA continuous noise. Workload was defined as the amount of attention demanded from an operator as measured by performance decrement on a secondary task while performing a primary and secondary task simultaneously. The secondary task was reading random numbers, and the primary task was reading word lists. Significant differences (p<.05) were found between the control condition and all experimental conditions. The low temperature and high temperature-continuous noise conditions were significantly different from the other conditions. Noise and temperature were found to significantly increase workload (p<05).


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