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Infrasound

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https://www.readbyqxmd.com/read/28514800/-from-the-experts-office-hearing-impairment-due-vibration-infrasound-ultrasound-and-or-bodysound
#1
T Brusis
No abstract text is available yet for this article.
May 2017: Laryngo- Rhino- Otologie
https://www.readbyqxmd.com/read/28503003/characterization-of-moderate-ash-and-gas-explosions-at-santiaguito-volcano-guatemala-from-infrasound-waveform-inversion-and-thermal-infrared-measurements
#2
S De Angelis, O D Lamb, A Lamur, A J Hornby, F W von Aulock, G Chigna, Y Lavallée, A Rietbrock
The rapid discharge of gas and rock fragments during volcanic eruptions generates acoustic infrasound. Here we present results from the inversion of infrasound signals associated with small and moderate gas-and-ash explosions at Santiaguito volcano, Guatemala, to retrieve the time history of mass eruption rate at the vent. Acoustic waveform inversion is complemented by analyses of thermal infrared imagery to constrain the volume and rise dynamics of the eruption plume. Finally, we combine results from the two methods in order to assess the bulk density of the erupted mixture, constrain the timing of the transition from a momentum-driven jet to a buoyant plume, and to evaluate the relative volume fractions of ash and gas during the initial thrust phase...
June 28, 2016: Geophysical Research Letters
https://www.readbyqxmd.com/read/28403175/altered-cortical-and-subcortical-connectivity-due-to-infrasound-administered-near-the-hearing-threshold-evidence-from-fmri
#3
Markus Weichenberger, Martin Bauer, Robert Kühler, Johannes Hensel, Caroline Garcia Forlim, Albrecht Ihlenfeld, Bernd Ittermann, Jürgen Gallinat, Christian Koch, Simone Kühn
In the present study, the brain's response towards near- and supra-threshold infrasound (IS) stimulation (sound frequency < 20 Hz) was investigated under resting-state fMRI conditions. The study involved two consecutive sessions. In the first session, 14 healthy participants underwent a hearing threshold-as well as a categorical loudness scaling measurement in which the individual loudness perception for IS was assessed across different sound pressure levels (SPL). In the second session, these participants underwent three resting-state acquisitions, one without auditory stimulation (no-tone), one with a monaurally presented 12-Hz IS tone (near-threshold) and one with a similar tone above the individual hearing threshold corresponding to a 'medium loud' hearing sensation (supra-threshold)...
2017: PloS One
https://www.readbyqxmd.com/read/28378979/exposure-to-infrasonic-noise-in-agriculture
#4
Bartosz Bilski
INTRODUCTION AND OBJECTIVES: Although exposure to audible noise has been examined in many publications, the sources of infrasound in agriculture have not been fully examined and presented. The study presents the assessment of exposure to infrasound from many sources at workplaces in agriculture with examples of possible ergonomic and health consequences caused by such exposure. MATERIALS AND METHOD: Workers'-perceived infrasonic noise levels were examined for 118 examples of moving and stationary agricultural machines (modern and old cab-type tractors, old tractors without cabins, small tractors, grinders, chargers, forage mixers, grain cleaners, conveyors, bark sorters and combine-harvesters)...
March 21, 2017: Annals of Agricultural and Environmental Medicine: AAEM
https://www.readbyqxmd.com/read/28372107/a-wide-angle-high-mach-number-modal-expansion-for-infrasound-propagation
#5
Jelle Assink, Roger Waxler, Doru Velea
The use of modal expansions to solve the problem of atmospheric infrasound propagation is revisited. A different form of the associated modal equation is introduced, valid for wide-angle propagation in atmospheres with high Mach number flow. The modal equation can be formulated as a quadratic eigenvalue problem for which there are simple and efficient numerical implementations. A perturbation expansion for the treatment of attenuation, valid for stratified media with background flow, is derived as well. Comparisons are carried out between the proposed algorithm and a modal algorithm assuming an effective sound speed, including a real data case study...
March 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28253705/modal-expansions-for-infrasound-propagation-and-their-implications-for-ground-to-ground-propagation
#6
Roger Waxler, Jelle Assink, Doru Velea
The use of expansions in vertical eigenmodes for long range infrasound propagation modeling in the effective sound speed approximation is investigated. The question of convergence of such expansions is related to the maximum elevation angles that are required. Including atmospheric attenuation leads to a non-self-adjoint vertical eigenvalue problem. The use of leading order perturbation theory for the modal attenuation is compared to the results of numerical solutions to the non-self-adjoint eigenvalue problem and conditions under which the perturbative result is expected to be valid are obtained...
February 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28059760/volcanic-tremor-and-plume-height-hysteresis-from-pavlof-volcano-alaska
#7
David Fee, Matthew M Haney, Robin S Matoza, Alexa R Eaton, Peter Cervelli, David J Schneider, Alexandra M Iezzi
The March 2016 eruption of Pavlof Volcano, Alaska, produced an ash plume that caused the cancellation of more than 100 flights in North America. The eruption generated strong tremor that was recorded by seismic and remote low-frequency acoustic (infrasound) stations, including the EarthScope Transportable Array. The relationship between the tremor amplitudes and plume height changes considerably between the waxing and waning portions of the eruption. Similar hysteresis has been observed between seismic river noise and discharge during storms, suggesting that flow and erosional processes in both rivers and volcanoes can produce irreversible structural changes that are detectable in geophysical data...
January 6, 2017: Science
https://www.readbyqxmd.com/read/27782589/acoustic-buffeting-by-infrasound-in-a-low-vibration-facility
#8
B P MacLeod, J E Hoffman, S A Burke, D A Bonn
Measurement instruments and fabrication tools with spatial resolution on the atomic scale require facilities that mitigate the impact of vibration sources in the environment. One approach to protection from vibration in a building's foundation is to place the instrument on a massive inertia block, supported on pneumatic isolators. This opens the questions of whether or not a massive floating block is susceptible to acoustic forces, and how to mitigate the effects of any such acoustic buffeting. Here this is investigated with quantitative measurements of vibrations and sound pressure, together with finite element modeling...
September 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27678397/budgerigars-melopsittacus-undulatus-do-not-hear-infrasound-the-audiogram-from-8%C3%A2-hz-to-10%C3%A2-khz
#9
Henry E Heffner, Gimseong Koay, Rickye S Heffner
The pure-tone thresholds of three budgerigars were determined from 8 Hz to 10 kHz. At a level of 60 dB sound pressure level (re 20 μN/m(2)), their hearing range extends 6.6 octaves from 77 Hz to 7.6 kHz, with a best sensitivity of 1.1 dB at 3 kHz. Unlike pigeons and chickens, budgerigars do not have better low-frequency hearing than humans. This difference implies anatomical, physiological, and ecological differences between birds that hear infrasound (so far, pigeons and chickens) and those that do not (budgerigars)...
September 28, 2016: Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology
https://www.readbyqxmd.com/read/27587311/pseudo-time-reversal-symmetry-and-topological-edge-states-in-two-dimensional-acoustic-crystals
#10
Jun Mei, Zeguo Chen, Ying Wu
We propose a simple two-dimensional acoustic crystal to realize topologically protected edge states for acoustic waves. The acoustic crystal is composed of a triangular array of core-shell cylinders embedded in a water host. By utilizing the point group symmetry of two doubly degenerate eigenstates at the Γ point, we can construct pseudo-time-reversal symmetry as well as pseudo-spin states in this classical system. We develop an effective Hamiltonian for the associated dispersion bands around the Brillouin zone center, and find the inherent link between the band inversion and the topological phase transition...
2016: Scientific Reports
https://www.readbyqxmd.com/read/27586769/acoustic-properties-in-the-low-and-middle-atmospheres-of-mars-and-venus
#11
Andi Petculescu
Generic predictions for acoustic dispersion and absorption in the atmospheres of Mars and Venus are presented. For Mars, Pathfinder and Mars Express ambient data and averaged thermophysical parameters are used as inputs to a preliminary model based on the continuum approximation for Mars' thin atmosphere-the need for Boltzmann-based treatment is discussed in the context of Knudsen numbers. Strong absorption constrains acoustic sensing within the Martian planetary boundary layer. For the dense atmosphere of Venus, the van der Waals equation of state is used...
August 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27569407/before-after-field-study-of-effects-of-wind-turbine-noise-on-polysomnographic-sleep-parameters
#12
Leila Jalali, Philip Bigelow, Mohammad-Reza Nezhad-Ahmadi, Mahmood Gohari, Diane Williams, Steve McColl
Wind is considered one of the most advantageous alternatives to fossil energy because of its low operating cost and extensive availability. However, alleged health-related effects of exposure to wind turbine (WT) noise have attracted much public attention and various symptoms, such as sleep disturbance, have been reported by residents living close to wind developments. Prospective cohort study with synchronous measurement of noise and sleep physiologic signals was conducted to explore the possibility of sleep disturbance in people hosting new industrial WTs in Ontario, Canada, using a pre and post-exposure design...
July 2016: Noise & Health
https://www.readbyqxmd.com/read/27522832/-birds-sense-of-direction
#13
REVIEW
Esa Hohtola
Birds utilize several distinct sensory systems in a flexible manner in their navigation. When navigating with the help of landmarks, location of the sun and stars, or polarization image of the dome of the sky, they resort to vision. The significance of olfaction in long-range navigation has been under debate, even though its significance in local orientation is well documented. The hearing in birds extends to the infrasound region. It has been assumed that they are able to hear the infrasounds generated in the mountains and seaside and navigate by using them...
2016: Duodecim; Lääketieteellinen Aikakauskirja
https://www.readbyqxmd.com/read/27475186/a-numerical-study-of-nonlinear-infrasound-propagation-in-a-windy-atmosphere
#14
R Sabatini, O Marsden, C Bailly, C Bogey
Direct numerical simulations of the two-dimensional unsteady compressible Navier-Stokes equations are performed to study the acoustic field generated by an infrasonic source in a realistic atmosphere. Some of the main phenomena affecting the propagation of infrasonic waves at large distances from the source are investigated. The effects of thermal and wind-related refraction on the signals recorded at ground level are highlighted, with particular emphasis on the phase shift induced by the presence of caustics in the acoustic field...
July 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27475150/detection-of-regional-infrasound-signals-using-array-data-testing-tuning-and-physical-interpretation
#15
Junghyun Park, Brian W Stump, Chris Hayward, Stephen J Arrowsmith, Il-Young Che, Douglas P Drob
This work quantifies the physical characteristics of infrasound signal and noise, assesses their temporal variations, and determines the degree to which these effects can be predicted by time-varying atmospheric models to estimate array and network performance. An automated detector that accounts for both correlated and uncorrelated noise is applied to infrasound data from three seismo-acoustic arrays in South Korea (BRDAR, CHNAR, and KSGAR), cooperatively operated by Korea Institute of Geoscience and Mineral Resources (KIGAM) and Southern Methodist University (SMU)...
July 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27470104/damage-to-hippocampus-of-rats-after-being-exposed-to-infrasound
#16
Meng Yao Zhang, Chen Chen, Xue Jun Xie, Sheng Long Xu, Guo Zhen Guo, Jin Wang
OBJECTIVE: The objective was to observe damage of hippocampus in rats after exposure to infrasound, and to assess HSP70 expression in hippocampus. METHODS: SD rats in the experimental group were exposed to 140 dB (8 Hz) infrasound for 2 h per day for 3 days. The morphology of the hippocampus was examined by transmission electronic microscopic (TEM). Cell apoptosis was observed by TUNEL staining at 0 h, 24 h, 48 h, and 2 w after exposure. HSP70 expression was detected by immunohistochemistry (IHC) and Western blotting (WB)...
June 2016: Biomedical and Environmental Sciences: BES
https://www.readbyqxmd.com/read/27369137/analysis-and-modeling-of-infrasound-from-a-four-stage-rocket-launch
#17
Philip Blom, Omar Marcillo, Stephen Arrowsmith
Infrasound from a four-stage sounding rocket was recorded by several arrays within 100 km of the launch pad. Propagation modeling methods have been applied to the known trajectory to predict infrasonic signals at the ground in order to identify what information might be obtained from such observations. There is good agreement between modeled and observed back azimuths, and predicted arrival times for motor ignition signals match those observed. The signal due to the high-altitude stage ignition is found to be low amplitude, despite predictions of weak attenuation...
June 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27369127/time-reversal-for-localization-of-sources-of-infrasound-signals-in-a-windy-stratified-atmosphere
#18
Joel B Lonzaga
Time reversal is used for localizing sources of recorded infrasound signals propagating in a windy, stratified atmosphere. Due to the convective effect of the background flow, the back-azimuths of the recorded signals can be substantially different from the source back-azimuth, posing a significant difficulty in source localization. The back-propagated signals are characterized by negative group velocities from which the source back-azimuth and source-to-receiver (STR) distance can be estimated using the apparent back-azimuths and trace velocities of the signals...
June 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27247701/antarctica-challenges-the-new-horizons-in-predictive-preventive-personalized-medicine-preliminary-results-and-attractive-hypotheses-for-multi-disciplinary-prospective-studies-in-the-ukrainian-akademik-vernadsky-station
#19
Yevhen V Moiseyenko, Viktor I Sukhorukov, Georgiy Yu Pyshnov, Iryna M Mankovska, Kateryna V Rozova, Olena A Miroshnychenko, Olena E Kovalevska, Stefan-Arpad Y Madjar, Rostyslav V Bubnov, Anatoliy O Gorbach, Kostiantyn M Danylenko, Olga I Moiseyenko
BACKGROUND: Antarctica is a unique place to study the health condition under the influence of environmental factors on the organism in pure form. Since the very beginning of the scientific presence of Ukraine in the Antarctic, biomedical research has been developed for the monitoring of individual biomarkers of winterers and medical accompaniment in Antarctic expeditions. The aim of the study was to analyze and discuss the retrospective data of long-term monitoring and observations in Ukrainian Antarctica station "Akademik Vernadsky," providing multi-scale biomedical information with regard to conditions of a perfect isolation from technological and social influences and under extreme environmental factors...
2016: EPMA Journal
https://www.readbyqxmd.com/read/27187031/wind-turbines-cause-chronic-stress-in-badgers-meles-meles-in-great-britain
#20
Roseanna C N Agnew, Valerie J Smith, Robert C Fowkes
A paucity of data exists with which to assess the effects of wind turbines noise on terrestrial wildlife, despite growing concern about the impact of infrasound from wind farms on human health and well-being. In 2013, we assessed whether the presence of turbines in Great Britain impacted the stress levels of badgers ( Meles meles ) in nearby setts. Hair cortisol levels were used to determine if the badgers were physiologically stressed. Hair of badgers living <1 km from a wind farm had a 264% higher cortisol level than badgers >10 km from a wind farm...
July 2016: Journal of Wildlife Diseases
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