Effects Of Low-frequency Noise Research Articles

Inversion strategies for Q estimation in viscoacoustic full-waveform inversion

Estimation of an attenuation parameter, represented by the quality factor Q, holds paramount importance in seismic exploration. One of the main challenges in Q estimation through viscoacoustic full-waveform inversion (FWI) is effectively decoupling Q from velocity. In this study, our objective is to enhance Q inversion by addressing critical aspects, such as gradient preconditioning, workflow, and misfit design. By developing a new preconditioner that approximates the diagonal of the Hessian, we facilitate automatic parameter tuning across different classes, ensuring comparable magnitudes of preconditioned gradients for velocity and Q. Moreover, our investigations confirm the efficacy of the two-stage hierarchical strategy in mitigating velocity- Q trade-offs, enabling more accurate Q estimation by first focusing on velocity reconstruction before jointly estimating velocity and Q. The analysis and numerical examples also highlight the importance of broadband data and long-offset acquisition for a reliable Q estimation. In addition, leveraging amplitude information can improve Q estimation to some extent, but careful consideration of frequency band and noise effects is necessary. We explore two misfit functions that capture amplitude variation with frequency in the time-frequency domain, noting their sensitivity to noise. To address this, we develop a differential strategy that can effectively mitigate the effects of low-frequency noise. This comprehensive study on enhancing Q estimation in viscoacoustic FWI offers valuable insights for multiparameter inversion in realistic scenarios.

A novel paradigm examining the remote induction of nocebo effects online.

Side effect information is routinely communicated online. However, limited experimental evidence exists regarding the role of this information in generating maladaptive health outcomes (i.e., the nocebo effect). A novel paradigm was developed to remotely induce the nocebo effect via provision of online side effect information. Participants were given information regarding the positive effects of low frequency noise (LFN). A proportion were additionally warned of LFN-induced side effects. Study 1 (N = 423) investigated the source of information (listed vs. socially communicated side effects), while Study 2 (N = 560) investigated the role of positive and negative affects on attenuating and exacerbating the nocebo effect. Pooled analysis (N = 983) explored the effect of negative and positive expectations on both the nocebo effect and positive outcomes. Across studies, a significant nocebo effect in the warned side effects occurred after LFN exposure. This did not vary by source of information (Study 1) nor was it attenuated via the induction of positive affect (Study 2). Both studies demonstrated a reduction in positive outcomes among those receiving side effect information. Pooled analysis revealed that negative, but not positive, expectations mediated the nocebo effect. Positive and negative expectations interacted to predict positive outcomes. Holding negative expectations appeared to block positive health outcomes. Specifically, when negative expectations were above average, there was no effect of positive expectations on positive outcomes. Nocebo effects were remotely generated via minimal provision of side effect information. Pooled analysis revealed that future interventions should target positive and negative expectations to reduce side effects. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Low-frequency noise impairs righting reflex behavior by disrupting central nervous system in the sea slug Onchidium reevesii

Anthropogenic noise has significantly increased due to human activities, posing a threat to the health and survival of marine organisms. However, current studies have often emphasized its effects on the physiological aspects of marine organisms, while ignored the relationship between the neuroendocrine system and behavior. This study aimed to evaluate the righting behavior and relevant physiological functions of the central nervous system (CNS) in sea slug (Onchidium reevesii) exposed to low-frequency noise and subsequent noise removal. The duration of the sea slugs' righting reflex increased with longer noise exposure time. The degree of neuronal cell damage and apoptosis were significantly increased and relevant gene expressions were affected (Glu, AChE, FMRFamide and CaMKII) (P < 0.05). After the removal of noise, the righting reflex speed gradually recovered, and the degree of neuronal cell damage, apoptosis and the expression levels of genes continued to decrease. Pearson correlation analysis showed that the righting time was positively correlated with CNS tissue and DNA damage, apoptosis rate, and negatively correlated with the expression levels of genes. Therefore, low-frequency noise exposure causes damage to the CNS of sea slugs, subsequently impairing their normal behavior. Sea slugs exhibited partial recovery within 384 h after removing noise. These findings provide valuable insights into the effects of low-frequency noise on the CNS and behavior of marine invertebrates.

Effect of low-frequency noise exposure on cognitive function: a systematic review and meta-analysis

BackgroundLow-frequency noise may cause changes in cognitive function. However, there is no established consensus on the effect of low-frequency noise on cognitive function. Therefore, this systematic review and meta-analysis aimed to explore the relationship between low-frequency noise exposure and cognitive function.MethodsWe conducted a systematic review and identified original studies written in English on low-frequency noise and cognition published before December 2022 using the PsycINFO, PubMed, Medline, and Web of Science databases. The risk of bias was evaluated according to established guidelines. A random-effects meta-analysis was performed where appropriate. To explore the association between low-frequency noise exposure and cognitive function, we reviewed eight relevant studies. These studies covered cognitive functions grouped into four domains: attention, executive function, memory, and higher-order cognitive functions. The data extraction process was followed by a random-effects meta-analysis for each domain, which allowed us to quantify the overall effect.ResultsOur analysis of the selected studies suggested that interventions involving low-frequency noise only had a negative impact on higher-order cognitive functions (Z = 2.42, p = 0.02), with a standardized mean difference of -0.37 (95% confidence interval: -0.67, -0.07). A moderate level of heterogeneity was observed among studies (p = 0.24, I2 = 29%, Tau2 = 0.03).ConclusionsOur study findings suggest that low-frequency noise can negatively impact higher-order cognitive functions, such as logical reasoning, mathematical calculation, and data processing. Therefore, it becomes important to consider the potential negative consequences of low-frequency noise in everyday situations, and proactive measures should be taken to address this issue and mitigate the associated potential adverse outcomes.

Wide-frequency-range vibration positioning based on adaptive TQWT for long-distance asymmetric interferometer sensor

The asymmetric dual Mach–Zehnder interferometer (ADMZI) based vibration sensor effectively extends the sensing distance, however, the asymmetry seriously deteriorates the positioning accuracy. In this paper, an adaptive tunable Q-factor wavelet transform (TQWT) based long-distance asymmetric sensing system is proposed and experimentally demonstrated for the positioning of wide-frequency-range knocking vibration signals. The TQWT can extract the time-frequency features of the non-stationary signals by performing multi-scale decomposition. Firstly, the positioning method adaptively determines the decomposition levels by analyzing the power spectrum of the vibration signals, which not only effectively suppresses the effect of low-frequency noise, but also accurately extracts the main time-frequency variation characteristics of the vibration signals with various bandwidths. Then, the time delay between the time-frequency characteristics is obtained using a cross-correlation algorithm, and the vibration position is demodulated. Experimental results show that the method can accurately locate vibration signals with bandwidths of 10–80 kHz at a sensing length of 125 km. For high-frequency, strong vibration signals, the standard deviation of the positioning is around 35.1 m. For low-frequency, weak signals, the proposed method can still achieve effective positioning compared with the traditional approaches with a standard deviation of approximately 238.1 m. The proposed scheme can significantly improve the applicability of the asymmetric interferometer based vibration sensing system.

A Proposal for Risk Assessment of Low-Frequency Noise in the Human–Machine–Environment System

Low-frequency noise, the frequency range from approximately 10 Hz to 200 Hz, has been recognized as a special environmental noise problem. The World Health Organization recognizes the special place of low-frequency noise as an environmental problem. Noise can damage hearing, and it affects the whole body. Low-frequency sound is heard by humans, but infrasound is not audible. Low-frequency sound is most often measured based on a weighting function of the frequency. The A-weighted level underestimates the effects of low-frequency noise. For the detrimental effects of low-frequency sound, it would be appropriate to apply measurements using Z-weighting. The aim of this paper was to propose a comprehensive method of acoustic risk assessment (CMARA) that implements the effects of low-frequency values of noise exposure. The proposed methodology has been applied in practice at four workplaces for seven work activities. A risk assessment using the proposed CMARA method for individual activities shows that the noise exposure time may pose a health risk in the occupational and environmental process due to exposure to low-frequency noise at the limit of audibility. A high risk was assessed for activities WA2 (machining) and WA3 (spot welding). This paper highlights the need to measure low-frequency noise using Z-filter weighting.

Comparison of cabin noise of turboprop and turbofan aircrafts

Turboprop aircrafts are typically used for transporting cargos and for low-capacity short-haul air transport between regional cities. The new designs of turboprop aircrafts tend to focus on noise and comfort level of the aircrafts. Although turboprop aircrafts are known to have relatively higher cabin noise, there are limited reported studies in the open literature examining the actual cabin noise level in commercial flights. In this study, the cabin noise of the ATR 72-500 turboprop aircraft was examined and compared with that of the Bombardier CRJ 900 turbofan aircraft during actual commercial flights. Both are passenger planes which are designed to carry fewer than 100 passengers and are deemed to be a more compatible comparison. Both are single isle aircraft with two seats on each side of the isle. The Bombardier CRJ 900 is found to have a lower cabin noise in terms of both dBA and dBC for both taxing and cruising. As the average equivalent continuous sound pressure level (Leq) for cabin noise is found to be well below 85 dBA, there is no risk of exceeding the daily exposure to noise of 85 dBA for eight hours under the National Institute for Occupational Safety & Health (NIOSH) regulation. However, as many reported studies have shown that prolonged exposure to low frequency noise may lead to disorders, discomfort, sensitivity to and irritability from noise, annoyance, hearing loss, and cardiovascular diseases, there may be a need to carry out a more detailed study of the effect of low frequency noise on passengers.

Signal processing to reduce dark noise impact in precision timing

We introduce a technique to mitigate the effects of low frequency noise on precision timing.The example of Dark Count Noise Rate (DCR) in Silicon Photomultipliers (SiPMs) is emphasized.This technique exploits the correlation between time shifts onthe leading edge of a signal and the residual slope of the baseline (due to noise) which remainsafter baseline subtraction. In fast timing applications (such as for Time-of-flight particle ID) the signal arrival time is typically captured on the signal leading edge. The signal risetime is often fixed by the physics of the sensor and input circuit. Then accurate pulse timing can be achieved by correcting a leading edge threshold time (depending on a slope proportional to both the Amplitude and the risetime) to a “constant fraction” time. This compensation for time walk due to amplitude fluctuations breaks down once we introduce interference from low frequency noise on the leading edge. In this paper we demonstrate that an additional measurement of the slope at threshold can be used to correct for this noise jitter.

On-Chip Mach-Zehnder-Like Interferometer for Atomic Spin Precession Detection

At present, most atomic spin precession detection schemes use discrete optical elements, which leads to bulky detection systems. However, chip-based spin precession detection schemes lack modulation, resulting in lower detection sensitivity. In this paper, we propose and simulatively demonstrate an integrated atomic spin precession detection scheme using an on-chip Mach-Zehnder-like interferometer. An on-chip polarization sorter is designed, with contrast ratio of 24dB and coupling efficiency of 16.8% at 795 nm. With this device, linearly polarized probe light that experienced optical rotation can be split and coupled into two waveguide arms of the interferometer. To avoid the effect of low frequency noise, our scheme uses a micro-heater to modulate the phase difference signal, allowing for high sensitivity detection. The whole detection system can reach micron size, which provides a practical new technique for high precision atomic sensors that can be integrated into chips.

A Sub-Electron-Noise Multi-Channel Cryogenic Skipper-CCD Readout ASIC

The MIDNA application specific integrated circuit (ASIC) is a skipper-CCD readout chip fabricated in a 65 nm LP-CMOS process that is capable of working at cryogenic temperatures. The chip integrates four front-end channels that process the skipper-CCD signal and performs differential averaging using a dual slope integration (DSI) circuit. Each readout channel contains a pre-amplifier, a DC restorer, and a dual-slope integrator with chopping capability. The integrator chopping is a key system design element in order to mitigate the effect of low-frequency noise produced by the integrator itself, and it is not often required with standard CCDs. Each channel consumes 4.5 mW of power, occupies 0.156 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> area and has an input referred noise of 2.7 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu\text{V}_{\text{rms}}$</tex-math> </inline-formula> . It is demonstrated experimentally to achieve sub-electron noise when coupled with a skipper-CCD by means of averaging samples of each pixel. Sub-electron noise is shown in three different acquisition approaches. The signal range is 6000 electrons. The readout system achieves 0.2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\text{e}^{-}}$</tex-math> </inline-formula> RMS by averaging 1000 samples with MIDNA both at room temperature and at 180 Kelvin.

The Effect of Low Frequency Noise on Working Speed and Annoyance.

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Low-frequency noise pollution impairs burrowing activities of marine benthic invertebrates

Sounds from human activities such as shipping and seismic surveys have been progressively invading natural soundscapes and pervading oceanic ambient sounds for decades. Benthic invertebrates are important ecosystem engineers that continually rework the sediment they live in. Here, we tested how low-frequency noise (LFN), a significant component of noise pollution, affects the sediment reworking activities of selected macrobenthic invertebrates. In a controlled laboratory setup, the effects of acute LFN exposure on the behavior of three abundant bioturbators on the North Atlantic coasts were explored for the first time by tracking their sediment reworking and bioirrigation activities in noisy and control environments via luminophore and sodium bromide (NaBr) tracers, respectively. The amphipod crustacean Corophium volutator was negatively affected by LFN, exhibiting lower bioturbation rates and shallower luminophore burial depths compared to controls. The effect of LFN on the polychaete Arenicola marina and the bivalve Limecola balthica remained inconclusive, although A. marina displayed greater variability in bioirrigation rates when exposed to LFN. Furthermore, a potential stress response was observed in L. balthica that could reduce bioturbation potential. Benthic macroinvertebrates may be in jeopardy along with the crucial ecosystem-maintaining services they provide. More research is urgently needed to understand, predict, and manage the impacts of anthropogenic noise pollution on marine fauna and their associated ecosystems.

Data Compression in the NEXT-100 Data Acquisition System.

NEXT collaboration detectors are based on energy measured by an array of photomultipliers (PMT) and topological event filtering based on an array of silicon photomultipliers (SiPMs). The readout of the PMT sensors for low-frequency noise effects and detector safety issues requires a grounded cathode connection that makes the readout AC-couple with variations in the signal baseline. Strict detector requirements of energy resolution better than 1% FWHM require a precise baseline reconstruction that is performed offline for data analysis and detector performance characterization. Baseline variations make it inefficient to apply traditional lossy data compression techniques, such as zero-suppression, that help to minimize data throughput and, therefore, the dead time of the system. However, for the readout of the SiPM sensors with less demanding requirements in terms of accuracy, a traditional zero-suppression is currently applied with a configuration that allows for a compression ratio of around 71%. The third stage in the NEXT detectors program, the NEXT-100 detector, is a 100 kg detector that instruments approximately five times more PMT sensors and twice the number of SiPM sensors than its predecessor, the NEXT-White detector, putting more pressure in the DAQ throughput, expected to be over 900 MB/s with the current configuration, which will worsen the dead time of the acquisition data system. This paper describes the data compression techniques applied to the sensor data in the NEXT-100 detector, which reduces data throughput and minimizes dead time while maintaining the event rate to the level of its predecessor, around 50 Hz.

A Configurable Interface for Analog Sensor Outputs

Reading out analog sensor outputs can be a challenging task at low frequencies because of the low frequency noise. To obtain a sensor signal clearly, special interface circuits are required. By using such circuits, analog signals are cleaned from offset, drift and 1/f noise. Besides, if the interface circuitry is configurable, it can be possible to interface to inputs at different frequency ranges. At the interface block, analog sensor output signal is moved to a frequency band where low frequency noise effects are not dominant by using chopping modulation technique. The frequency-shifted signal is then filtered using various filter types. To remove the low frequency noise before moving the signal back to the original band, Gm-C filter is used. The entire topology can be configured by a 5-bit digital to analog converter (DAC) called Biasing DAC (BDAC). This allows us to digitally change the biasing current of operational transconductance amplifiers (OTA), so that OTA based amplifiers and filters can operate at different frequency ranges. As conclusion, a configurable analog sensor interface has been designed. The design and layouts have been realized and simulated in Cadence Virtuoso using UMC 130nm CMOS technology.

Coincidence of pressure pulsations with excitation of mechanical vibrations of hydraulic system components: An experimental study

This paper discusses certain excitations that affect the components of hydraulic systems: pipes and valves. The negative effects of low-frequency noise and vibration on humans were also pointed out. Particular attention is given to the effect of pulsatile flow on the structure of hydraulic components. Pressure pulsations in a hydraulic system have been shown to generate and transmit mechanical vibrations across a wide spectrum of frequencies, and the negative consequences of this phenomenon have been pointed out. Based on the latest generation of proportional directional control valve, a special stand was built to generate pressure pulsations over a wide frequency range (up to 350 Hz). Amplitude-frequency spectra of mechanical vibrations and pressure pulsations were used instead of time courses in the considerations. The paper concludes that effort must be made to reduce the amplitudes of pressure pulsations in hydraulic systems, particularly in the low-frequency spectrum.

Effect of low-frequency noise on the survival rate and immunity of infected Vibrio parahaemolyticus sea slug (Onchidium reevesii)

Anthropogenic noise in the marine environment has become a global environmental pollutant that affects the behavior, physiology and immunity of marine animals. However, the resistance of marine animals to pathogens while under the influence of noise is a topic that has received little attention. To assess the immune defense response of sea slugs against pathogens when exposed to low frequency noise, we performed 120 h exposure experiments on sea slugs after a Vibrio parahaemolyticus application in low frequency noise at 500 Hz and 1000 Hz. We found that after the infection with V. parahaemolyticus, the survival rate of the sea slugs decreased, the apoptosis rate and reactive oxygen species (ROS) production of hemocytes increased significantly (P < 0.05), the proliferation of hemocytes accelerated, the activities of enzymes such as superoxide dismutase (SOD), catalase (CAT), alkaline phosphatase (AKP), alanine transaminase (ALT) and lysozyme (LZM) in the hepatopancreas increased significantly, and the expression of TNF signaling pathway-related genes (TNF-α, FADD, Caspase 8, Caspase 3) and Hsp70 genes were generally upregulated. In addition, exposure of sea slug after infected with V. parahaemolyticus to low frequency noise resulted in a significant increase in both antioxidant and immune parameters, which were positively correlated with frequency. The results showed that noise frequency and exposure time had an interactive effect on the above indicators. In summary, low-frequency noise exposure increases the risk of pathogenic infections in sea slugs and exacerbates the negative effects on the antioxidant capacity and immune metabolism of the organism.

Is Enough Attention Paid to the Health Effects of Low-Frequency Noise in Today's Society?

Is Enough Attention Paid to the Health Effects of Low-Frequency Noise in Today's Society?

The Effect of Low Frequency Noises Exposure on the Precision of Human at the Mathematical Tasks.

Background:Low-frequency noise is produced from different sources in the working environments such as pumps. Thus, the aim of this study was to investigate the effect of low-frequency noise on precision and focusing of the studied subjects.Methods:This cross-sectional–interventional study was performed on 13 students of Isfahan University of Medical Sciences. The precision of individual subjects was evaluated using the mental arithmetic test. The sound sources with frequencies of 125, 250, and 1000 Hz at 75, 85, and 95 dB sound pressure levels. Also, the rate of precision was measured before the exposure (time “zero”), and at 45 and 90 min. SPSS (Ver. 26) software was used to analyze the data.Results:Comparison of the precision scores of the individuals between the frequencies of 125 and 250 Hz at the sound pressure level of 75 dB and at 45 min (P = 0.032). And 90 min (P = 0.006). And also, the frequencies of 250 Hz and 1000 Hz at the time of 45 min. At the sound pressure levels of 85 dB (P = 0.019). And 95 dB (P = 0.043) and at the time of 90 min. At the sound pressure levels of 85 dB (0.027). And 95 dB (P = 0.009) demonstrated a significant difference.Conclusions:We concluded that low frequency noises could reduce the person's precision. While for 125 Hz noises, just increasing of the exposure time was effective on the precision reduction. But for 250 Hz noises, both parameters increasing including exposure time and sound pressure levels, was effective.

Transcriptome Analysis of the Central Nervous System of Sea Slug (Onchidium reevesii) Exposed to Low-Frequency Noise

Low-frequency noise has become a marine pollutant that cannot be ignored, but most studies have focused on the behavioral and physiological effects on marine vertebrates, with few studies in marine mollusks. Therefore, sea slug was used in this study to investigate the effect of low-frequency noise on its physiological aspects. This experiment was designed with different low-frequency noise (0, 100, 300, and 500 Hz) and different stimulation times (0, 6, and 12 h) to measure superoxide dismutase (SOD), malondialdehyde (MDA), and catalase (CAT) activities in hemolymph and transcriptomics in the control (C) and 6 and 12 h groups (L1 and L2) with 500 Hz noise. The results showed a positive correlation between antioxidant enzyme activity and low-frequency noise frequency (P &amp;lt; 0.05) and no correlation with time (P &amp;gt; 0.05). In central nervous system (CNS) transcriptomics, 2,460 and 3,268 genes had upregulated expression and 2,765 and 2,783 genes had downregulated expression in the L1 and L2 groups, respectively, compared to the C group. According to Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, low-frequency noise mainly affects signaling pathways such as cytokine-cytokine receptor interaction, the FoxO signaling pathway, natural killer cell-mediated cytotoxicity, apoptosis immune-related pathways, and energy metabolic pathways such as glycolysis, the TCA cycle, and glycerophospholipid metabolism, as well as neurological pathways such as GABAergic synapses, the synaptic vesicle cycle, amyotrophic lateral sclerosis (ALS) and other neurological pathways. This study would provide valuable reference information on the potential response of mollusks to low-frequency noise stress.

Effects of low-frequency noise from wind turbines on heart rate variability in healthy individuals

Wind turbines generate low-frequency noise (LFN, 20–200 Hz), which poses health risks to nearby residents. This study aimed to assess heart rate variability (HRV) responses to LFN exposure and to evaluate the LFN exposure (dB, LAeq) inside households located near wind turbines. Thirty subjects living within a 500 m radius of wind turbines were recruited. The field campaigns for LFN (LAeq) and HRV monitoring were carried out in July and December 2018. A generalized additive mixed model was employed to evaluate the relationship between HRV changes and LFN. The results suggested that the standard deviations of all the normal to normal R–R intervals were reduced significantly, by 3.39%, with a 95% CI = (0.15%, 6.52%) per 7.86 dB (LAeq) of LFN in the exposure range of 38.2–57.1 dB (LAeq). The indoor LFN exposure (LAeq) ranged between 30.7 and 43.4 dB (LAeq) at a distance of 124–330 m from wind turbines. Moreover, households built with concrete and equipped with airtight windows showed the highest LFN difference of 13.7 dB between indoors and outdoors. In view of the adverse health impacts of LFN exposure, there should be regulations on the requisite distances of wind turbines from residential communities for health protection.