Elevated Noise Levels Research Articles

Long range airgun inter-pulse noise field in offshore northern Australian waters

Elevated ambient noise levels have been shown to affect marine fauna communication. The effects due to increased noise levels from the multipath propagation and reverberation of airgun pulses over large distances is a relatively new area of interest. This research examines a distant seismic survey opportunistically recorded at two locations during a long-term monitoring program in the Timor Sea, Australia. During the analyzed period, the survey was between 168 and 235 km from the Autonomous Multichannel Acoustic Recorders (AMAR). The noise levels between airgun pulses were examined using an incremental computation method based on calculating the root-mean-square sound pressure level in 125 ms sub-intervals. These were compared to ambient noise levels from the month prior to commencement of the seismic survey and during line turns. The received pulse levels and length differences, and therefore inter-pulse noise field, between the recorders were greater than expected given the proportional distance to sour...

Meeting the Needs of Avid Book Readers: Access, Space, Concentration Support and Barrier Mitigation

ABSTRACTContemporary libraries perform multiple roles that greatly expand the scope of traditional service and resource provision. In order to determine how libraries can best meet the needs of avid book reading clientele, more needs to be known about their preferences of access and space, as well as barriers to their concentration and performance of sustained reading. Findings from the 2015 International Study of Avid Book Readers suggest that libraries should offer comfortable and quiet spaces conducive to reading for pleasure, that are responsive to the time, cost and concentration barriers that avid readers face, and not assume that avid readers will easily adapt to library environments with elevated noise levels.

Auditory Discrimination of Natural and High-Pass Filtered Bark Vocalizations in a California Sea Lion (Zalophus californianus).

A California sea lion performed a psychophysical auditory discrimination task with a set of six stimuli: three barks recorded from conspecific males and high-pass filtered versions of the barks that removed the majority of energy at fundamental frequencies. Discrimination performance and subject reaction times (RTs) suggested that the vocalizations were all perceived as fairly dissimilar. This preliminary study hints that low-frequency components are a salient part of the California sea lion bark despite elevation of this species' aerial hearing thresholds and the potential for elevated environmental noise levels at frequencies below 1 kHz.

Noise as an external effect of traffic and transportation

The paper deals with the basic concepts and characteristics of external effects of traffic and transport, with an emphasis on the impact of traffic noise as one of the main external effects of transport nowadays. The main negative impacts of traffic noise on human life and social activities are given as well as the causes of elevated levels of noise from road, rail and tram traffic. In addition, the paper provides a review of the common measures that can be applied to reduce the impact of noise generated as a result of traffic and transport activities. In the end, we made a short review of the current situation regarding the impact of traffic noise in the Republic of Serbia and the Serbian Armed Forces.

Parametric method for the noise risk assessment of professional orchestral musicians.

Background:The Occupational Health and Safety (OH&S) literature shows that noise could represent a risk factor for professional orchestral musicians. The continuative exposition to elevated noise levels and the particular nature of the activity make necessary an “atypical” OH&S approach, which was identified to be necessarily organizational.Materials and Methods:In this study, a parametric-based method for orchestral exposure assessment and management was developed. The goal was to achieve a predictive tool to involve safety in the decision making of concert season program. After setting the parameters, the project's hypothesis was defined and then validated through a yearly-scale monitoring on an important European symphonic orchestra. Moreover, workers’ exposure was assessed from the parametric study by a wide measurement campaign.Results:A general validation of the method was obtained by the verification of the main parameters’ (repertoire, headcount, and disposition) significant influence on the sound pressure levels produced by the orchestra. Exposure levels comparable to the trends in literature for symphonic orchestras were observed, with criticalities among brass musicians, which was the only group exceeding the upper exposure action values.Conclusion:This research has emphasized that the exposure condition of musicians can be critical and requires the implementation of improvement plans. The study has shown that the predictive analysis can be performed on parameters describing the concert's emissive characteristics. The future development of research currently under study will focus on the concert's pieces and the use of parameters as indicators of the exposure context.

Noise in gene expression is coupled to growth rate

Genetically identical cells exposed to the same environment display variability in gene expression (noise), with important consequences for the fidelity of cellular regulation and biological function. Although population average gene expression is tightly coupled to growth rate, the effects of changes in environmental conditions on expression variability are not known. Here, we measure the single-cell expression distributions of approximately 900 Saccharomyces cerevisiae promoters across four environmental conditions using flow cytometry, and find that gene expression noise is tightly coupled to the environment and is generally higher at lower growth rates. Nutrient-poor conditions, which support lower growth rates, display elevated levels of noise for most promoters, regardless of their specific expression values. We present a simple model of noise in expression that results from having an asynchronous population, with cells at different cell-cycle stages, and with different partitioning of the cells between the stages at different growth rates. This model predicts non-monotonic global changes in noise at different growth rates as well as overall higher variability in expression for cell-cycle–regulated genes in all conditions. The consistency between this model and our data, as well as with noise measurements of cells growing in a chemostat at well-defined growth rates, suggests that cell-cycle heterogeneity is a major contributor to gene expression noise. Finally, we identify gene and promoter features that play a role in gene expression noise across conditions. Our results show the existence of growth-related global changes in gene expression noise and suggest their potential phenotypic implications.

Effects of Hyperlipidemia on Noise Induced Hearing Loss (NIHL).

Likelihood of developing noise induced hearing loss (NIHL) is affected by some factors such as genes, nutrition and healthy hearing habits. We investigated this study to determine the effect of hyperlipidemia on NIHL. In a case-control study, 144 workers who exposed to continuous noise more than 85 dBA (88-89 dBA) from a textile factory in Tehran were examined. Serum Blood test results as index for dyslipidemi, were collected and audiometry tests were carried out to analyze the association of hyperlipidemian and NIHL. The mean±SD of Cholesterol level for NIHL and control were 188.19 (28.46) and 159.00 (26.66) mg/dL respectively. Also the mean±SD of Triglyceride level for NIHL and control were 203.75 (53.92) and 105.00 (30.50) mg/dL consecutively. After adjusting odds ratio (OR) for NIHL, only hypertriglyceridemia had association with NIHL. (aOR=1.07; 95% CI 1.04-1.10), and there wasn't any relation between hypercholestomia and NIHL (aOR=1.02; 95% CI 0.99-1.05). Workers with hypertriglyceridemia are at increased risk for NIHL. In factories with elevated noise levels, besides hearing conservation programs, attention to blood serum level of workers and healthy diet are proposed to help in preserving hearing threshold.

Traveling Crossflow Instability for the HIFiRE-5 Elliptic Cone

A 38.1%-scale model of the Hypersonic International Flight Research Experimentation Program’s Flight Five 2:1 elliptic cone flight vehicle was used to investigate the traveling crossflow instability in a Mach 6 quiet wind tunnel. Traveling crossflow waves were detected with pressure sensors mounted flush with the model surface. The crossflow instability phase speed and wave angle were calculated from the cross spectra of the three pressure sensors. Both quantities showed good agreement with linear stability theory. Duplicate runs at the same initial conditions showed excellent repeatability in traveling crossflow wave properties. Traveling crossflow waves in quiet flow showed very low levels of nonlinear interactions. No traveling crossflow waves were observed for any Reynolds number for elevated freestream noise levels, but transition occurred for a much lower Reynolds number than in quiet flow. Due to the lack of nonlinear growth in quiet flow and the absence of traveling crossflow waves in noisy flow, it appeared that the traveling crossflow instability was not the primary transition mechanism on the model for quiet or noisy flow in this wind tunnel.

The Cry of the Child and its Relationship to Hearing Loss in Parental Guardians and Health Care Providers

In this study the authors investigate the sound pressure levels produced by crying children and discuss the possible adverse effects that direct exposure may impose on a tending guardian or healthcare professional. Sound intensity levels from various pediatric patients (N = 26) were measured under two segregate conditions, one imitating the exposure of an examining physician and the other resembling that of parental guardians. Interestingly, all of the recorded sound levels fell between 99–120 dB(A) of sound pressure; children presenting the greatest risk for intense cries with potentially harmful sound intensities were between the ages of 9 months and 6 years. The authors found that elevated noise levels produced from crying children can cause acute discomfort and mild pain to those exposed. In addition, there is a theoretical risk that chronic exposure to these intense sound pressures may result in noise-induced hearing loss in a parental guardian or an examining physician. Parents of young children may be more likely to succumb to impulsive reactions in attempting to arrest the crying, which could be a precipitating factor for child abuse, responding to physical stress as much as emotional stress. Social workers and medical personnel should consider suggesting the use of ear plugs by parental guardians of frequently crying children as a modality for the prevention of child abuse.

RESEARCH AND EVALUATION OF KART NOISE SPREAD INTO THE LIVING ENVIRONMENT / GOKARTŲ KELIAMO TRIUKŠMO SKLAIDOS Į GYVENAMĄJĄ APLINKĄ TYRIMAI IR VERTINIMAS

The paper examines kart noise propagation in the living environment and sought measures for suppressing it. To conduct experimental studies, precision sound level analyzer Bruel & Kjaer 2260th has been used. In cooperation with the Lithuanian Hydrometeorological Service, data on relative humidity, wind speed and direction, soil surface temperature and air temperature have been applied. According to the Lithuanian Hygiene Standard HN 33:2011 Noise Thresholds in Residential and Public Buildings and Their Environment, the areas with an elevated noise level are identified thus selecting noise reduction measures aimed at reducing noise levels up to the permitted ones. The analysis of the obtained results has focused on the regularities between noise propagation and meteorological events and their impact on the spread of noise. The environmental factors more or less influencing the climate and noise spread in the living area have been determined. With reference to the received information, the ways to reduce noise have been suggested. Straipsnyje nagrinėjamas gokartų keliamo triukšmo sklidimas į gyvenamąją aplinką ir ieškoma priemonių jam slopinti. Eksperimentiniams tyrimams atlikti buvo naudojamas precizinis garso lygio analizatorius „Bruel&Kjaer 2260“. Bendradarbiaujant su Lietuvos hidrometeorologijos tarnyba panaudoti santykinės oro drėgmės, vėjo stiprumo ir krypties, dirvožemio paviršiaus temperatūros bei oro temperatūros duomenys. Vadovaujantis Lietuvos higienos normomis HN 33:2011 „Triukšmo ribiniai dydžiai gyvenamuosiuose ir visuomeninės paskirties pastatuose bei jų aplinkoje“ nustatomos zonos, kuriose triukšmo lygis yra viršijamas, ir parenkant triukšmo mažinimo priemones siekiama triukšmą sumažinti iki leidžiamųjų normų. Gautų rezultatų analizės metu ieškoma dėsningumų tarp triukšmo sklidimo ir meteorologinių reiškinių bei jų daroma įtaka triukšmo plitimui. Nustatomi aplinkos klimato veiksniai, darantys įtaką ar mažiau veikiantys triukšmo sklaidą gyvenamojoje teritorijoje. Atsižvelgiant į gautus rezultatus siūlomi triukšmo mažinimo būdai.

High frequency components of ship noise in shallow water with a discussion of implications for harbor porpoises (Phocoena phocoena).

Growing ship traffic worldwide has led to increased vessel noise with possible negative impacts on marine life. Most research has focused on low frequency components of ship noise, but for high-frequency specialists, such as the harbor porpoise (Phocoena phocoena), medium-to-high frequency noise components are likely more of a concern. To test for biologically relevant levels of medium-to-high frequency vessel noise, different types of Automatic Identification System located vessels were recorded using a broadband recording system in four heavily ship-trafficked marine habitats in Denmark. Vessel noise from a range of different ship types substantially elevated ambient noise levels across the entire recording band from 0.025 to 160 kHz at ranges between 60 and 1000 m. These ship noise levels are estimated to cause hearing range reduction of >20 dB (at 1 and 10 kHz) from ships passing at distances of 1190 m and >30 dB reduction (at 125 kHz) from ships at distances of 490 m or less. It is concluded that a diverse range of vessels produce substantial noise at high frequencies, where toothed whale hearing is most sensitive, and that vessel noise should be considered over a broad frequency range, when assessing noise effects on porpoises and other small toothed whales.

Timing vocal behavior: Lack of temporal overlap avoidance to fluctuating noise levels in singing Eurasian wrens

Many animals live in or near urban areas that have become increasingly widespread and noisy over the last century. Especially those species that rely heavily on acoustics for communication may be affected by these elevated anthropogenic noise levels. Many bird species that sing to defend their territories and to attract mates may have to exploit specific noise coping strategies to persist in such acoustically challenging conditions. Eurasian wrens (Troglodytes troglodytes), like several other bird species, have been shown in a previous experiment to time their vocalizations such that they avoid overlap with other singing birds. Here, we tested whether Eurasian wrens also time their songs to avoid overlap with fluctuating anthropogenic noise. However, we did not find any evidence in favor of this potential phenomenon. Territorial wrens persisted in singing without temporal adjustments in noisy territories with ‘natural’ fluctuations of traffic noise levels as well as during experimental exposure to intermittent white noise.

Increased noise levels have different impacts on the anti-predator behaviour of two sympatric fish species.

Animals must avoid predation to survive and reproduce, and there is increasing evidence that man-made (anthropogenic) factors can influence predator−prey relationships. Anthropogenic noise has been shown to have a variety of effects on many species, but work investigating the impact on anti-predator behaviour is rare. In this laboratory study, we examined how additional noise (playback of field recordings of a ship passing through a harbour), compared with control conditions (playback of recordings from the same harbours without ship noise), affected responses to a visual predatory stimulus. We compared the anti-predator behaviour of two sympatric fish species, the three-spined stickleback (Gasterosteus aculeatus) and the European minnow (Phoxinus phoxinus), which share similar feeding and predator ecologies, but differ in their body armour. Effects of additional-noise playbacks differed between species: sticklebacks responded significantly more quickly to the visual predatory stimulus during additional-noise playbacks than during control conditions, while minnows exhibited no significant change in their response latency. Our results suggest that elevated noise levels have the potential to affect anti-predator behaviour of different species in different ways. Future field-based experiments are needed to confirm whether this effect and the interspecific difference exist in relation to real-world noise sources, and to determine survival and population consequences.

Sequence-based acoustic noise reduction of clinical MRI scans

Clinical MRI patients typically experience elevated acoustic noise levels of 80-110 dB(A). In this study, standard clinical turbo spin echo (TSE) and gradient echo (GRE) sequences were optimized for reduced acoustic noise at preserved diagnostic image quality. The physical sources of acoustic noise generation in an MRI gradient coil were analyzed. A sequence conversion algorithm was derived that optimized the gradient time scheme for an arbitrary MRI sequence, preserving the governing spin physics. The algorithm was applied to generate "quiet" versions of standard clinical TSE and GRE sequences. The first volunteer images indicated that contrast-to-noise ratio and perceived diagnostic image quality remained on the same level for the algorithmic optimization. Additional careful TSE- and GRE-specific protocol adaptions yielded total acoustic noise reductions of up to 14.4 dB(A) for the TSE and up to 16.8 dB(A) for the GRE. A physical sound pressure reduction of 81% (TSE) and 86% (GRE) for MRI patients was achieved. The results can be used to render MRI scans more patient-friendly in clinical practice, particularly for patients who are young, scared, or elderly.

Noise exposure level of the drivers of heavy duty diesel trucks

Noise exposure is a key factor that influences the health and performance of truck drivers. This study measured the in-cab noise level status of 20 new, 2007 or 2008 model heavy-duty diesel trucks from four different manufacturers under actual driving conditions. Overall in-cab noise levels were found to be below 8-hour NIOSH (The National Institute for Occupational Safety and Health) and OSHA (Occupational Safety & Health Administration) standard limit values. Results indicated slightly higher noise levels occurred while driving on the federal interstate when compared to driving on the state highway. It is believed that noise from tires, engine and wind impacting the cab at higher road speeds contributed to the elevated noise levels measured during interstate travel because speed limits are higher on the interstate than on state highways. These results could serve as baseline data from which future similar studies may determine if truck designs have changed the existing state of these conditions for truck drivers.

Evidence of the Lombard effect in fishes

Noise can be problematic for acoustically communicating organisms due to the masking effect it has on acoustic signals. Rapid expansion of human populations, accompanied by noise that comes with industrialization and motorized transportation, poses a threat for many acoustically communicating species. Although a significant amount of effort has been made exploring the responses of organisms inhabiting marine and terrestrial environments to elevated noise levels, relatively little has been directed toward organisms inhabiting small, lotic, freshwater systems. The aim of this study was to determine what effect elevated noise levels have on acoustic signals and inter-fish distance during sound production in the Blacktail Shiner, Cyprinella venusta. We hypothesized, based on the behaviors of other vocal organisms, that C. venusta would compensate for elevated noise levels by decreasing distance between sender and receiver, increasing signal amplitude (Lombard effect), or by changing temporal patterns to increase call redundancy. Using an experimental approach, we found that C. venusta altered several acoustic components under noisy conditions. Most notably, spectral levels of acoustic signals were increased in background noise, indicating presence of the Lombard effect in fishes. Inter-fish distance was typically not different between noisy and quiet conditions, although one circumstance did show a significantly smaller inter-fish distance under noisy conditions.

Reliability of high‐resolution electron backscatter diffraction determination of strain and rotation variations using phase‐only and cross correlation

This contribution analyzes the reliability of strain and rotation variation determination using cross‐ as well as phase‐only correlation of experimental wide‐angle electron backscatter diffraction (EBSD) patterns. For both rotation and three‐point bending the resulting displacement gradient tensor components are examined in terms of magnitude and statistical scatter as a function of various correlation procedure parameters and signal‐to‐noise ratio. It is shown that on the one hand the Fourier filter width has a major impact on the strain results. At higher noise level a smaller filter width has to be applied for obtaining maximum precision. On the other hand, the influence of the degree of overlap of the regions of interest positioned in the patterns is less important. For both rotation and bending experiments the cross‐correlation variant yields a smaller standard deviation with respect to phase‐only correlation, in particular for elevated noise level. The difference is attributed to the stronger propagation of noise effects in the course of phase‐only correlation function calculation and fitting. In the rotation experiment a standard deviation of ∼1.0 × 10−4, averaged over the displacement gradient tensor components, and a rotational precision of ∼1.5 × 10−4 rad have been achieved by using optimized evaluation settings.

The Data Link Layer Protocols for Underwater Acoustic Networks

The efficiency of service of Underwater Acoustic Networks is restricted by the acoustic channel characteristic, such as the low bandwidth , high varying multipath and elevated noise levels. In addition, the lifetime of Underwater Acoustic Networks is influenced greatly by the limited battery power. This paper designs an Underwater Acoustic Networks and poses the data link layer protocols including the logical link control protocol and the media access control protocol. The simulation results have demonstrated that the protocols are of certain applicability in underwater acoustic channel environment that maximize throughput and reliability while minimizing end-to-end delay. In the event of low offered load, the protocol can satisfy the requirment of Underwater Acoustic Networks.

Epidemiology of Health Concerns Among Collegiate Student Musicians Participating in Marching Band

Participation in marching band requires intense physical and mental requirements, altered and potentially elevated biomechanical demands related to performing musical instruments while marching, routine exposures to elevated noise levels and at times hazardous weather conditions, and time commitments for practice and travel. Unfortunately, there are no known epidemiologic studies that systematically examine the perception of health-related consequences among college students participating in a collegiate marching band. There are no known studies that attempt to understand if the perceived consequences of marching band are different for students majoring in music compared to non-music major students. In response to this deficiency, this study collected and characterized occupational health patterns and concerns associated with participation in a collegiate marching band. Members of a large collegiate marching band (n=246/310, 76%) responded to a 70-item epidemiologic survey. Results reveal patterns of health concerns and how they differ when compared across music majors vs non-music majors and instrument groups.

Contribution of iceberg sounds to the ambient noise budget in the South Pacific Ocean

On May 2002, C19, a 5500 km2 iceberg calved from the Ross Ice Shelf, eventually drifting eastward into the open Pacific Ocean by 2008. As it sailed into warmer waters, thermal and wind stresses caused the iceberg to crack and break apart. These resulting “icequakes” projected wideband acoustic energy into the water column, influencing the regional ambient noise environment. Icequake noise was persistent and strong enough to be observed by NOAA’s eastern equatorial Pacific moored hydrophone (EEP-NW at 8N, 110W) as well as the hydroacoustic station of International Monitoring System (IMS) on Juan Fernandez Island (H03N at 33.44S, 78.91W). Elevated noise levels (maximum of ~+3 dB at NOAA’s EEP and ~+7 dB at IMS H03N hydrophones) were observed by both stations from early 2008 when C19a first appeared in the Pacific until it drifted into the Atlantic Ocean in early 2009. C19a’s icequake and calving activity was also most frequent during this same period. Seasonal changes and long-term trends in ambient noise levels at NOAA’s EEP-NW acoustic mooring (1996–2009) and IMS Juan Fernandez (2003–2010 years) and the unique acoustic role icebergs play in the Southern Ocean will be presented.