Noise pollution must be considered to achieve sustainable cities because current levels of exposure to environmental noise are a considerable risk to the health and quality of life of citizens. Urban ...features and sound levels were registered in 150 streets in the Chilean cities of Talca and Valdivia to analyze the relationship between both types of variables. Urban variables related to street location, urban land use, street geometry, road traffic control, and public and private transportation showed very significant correlations with the noise levels, and multiple regression models were developed from these variables for each city. Models using only urban variables in Valdivia and Talca explained 71% and 73%, respectively, of the variability of noise. The prediction error was similar in the different types of urban roads and did not exhibit significant differences between models developed in different cities. The urban models developed in one city could, therefore, be used in other similar cities. Considering the usefulness of these variables in urban planning, these models can be a useful tool for urban planners and decision-makers to implement action plans regarding noise pollution.
Acute effects of anthropogenic sounds on marine mammals, such as from military sonars, energy development, and offshore construction, have received considerable international attention from ...scientists, regulators, and industry. Moreover, there has been increasing recognition and concern about the potential chronic effects of human activities (e. g., shipping). It has been demonstrated that increases in human activity and background noise can alter habitats of marine animals and potentially mask communications for species that rely on sound to mate, feed, avoid predators, and navigate. Without exception, regulatory agencies required to assess and manage the effects of noise on marine mammals have addressed only the acute effects of noise on hearing and behavior. Furthermore, they have relied on a single exposure metric to assess acute effects: the absolute sound level received by the animal There is compelling evidence that factors other than received sound level, including the activity state of animals exposed to different sounds, the nature and novelty of a sound, and spatial relations between sound source and receiving animals (i. e., the exposure context) strongly affect the probability of a behavioral response. A more comprehensive assessment method is needed that accounts for the fact that multiple contextual f actors can affect how animals respond to both acute and chronic noise. We propose a three-part approach. The first includes measurement and evaluation of context-based behavioral responses of marine mammals exposed to various sounds. The second includes new assessment metrics that emphasize relative sound levels (i. e., ratio of signal to background noise and level above hearing threshold). The third considers the effects of chronic and acute noise exposure. All three aspects of sound exposure (context, relative sound level, and chronic noise) mediate behavioral response, and we suggest they be integrated into ecosystem-level management and the spatial planning of human offshore activities. Los efectos agudos de los sonidos antropogénicos (como los provenientes de sonares militares, desarrollo energéticos y construcciones cercanas a la costa) sobre mamíferos marinos han recibido considerable atención internacional de parte de científicos, reguladores e industriales. Más aun, hay creciente reconocimiento y preocupación sobre los efectos crónicos potenciales de las actividades humanas (e. g., navegación). Se ha demostrado que los incrementos de la actividad humana y del ruido pueden alterar el habitat de mamíferos marinos y potencialmente enmascarar la comunicación de especies que dependen de sonidos para buscar pareja, alimentarse, evitar depredadores y navegar. Sin excepción, las agencias reguladoras que han evaluado y manejado los efectos del ruido sobre mamíferos marinos solo han atendido los efectos agudos del ruido sobre la audición y la conducta. Más aun, se han basado en una sola medida de exposición para evaluar efectos agudos: el nivel de sonido absoluto recibido por el animal. Hay evidencia de peso de que otros f actores, diferentes al nivel de sonido recibido, incluyendo el estado de los animales expuestos a sonidos diferentes, la naturaleza y novedad del sonido y las relaciones espaciales entre la fuente del sonido y los animales receptores, afectan fuertemente a la probabilidad de respuesta. Se requiere de una evaluación más integral que considere el hecho de que factores contextúales múltiples pueden afectar la manera en que los animales responden a ruido tanto agudo como crónico. Proponemos un método compuesto de tres partes. La primera incluye la medición y evaluación de las respuestas conductuales basadas en el contexto de mamíferos marinos expuestos a sonidos diversos. La segunda incluye medidas de evaluación nuevas que enfatizan los niveles de sonido relativo (i. e., la relación señal-ruido de fondo y el nivel por encima del umbral de audición). La tercera considera los efectos de la exposición a ruido crónico y agudo. Los tres aspectos de la exposición a sonidos (contexto, nivel de sonido relativo y ruido crónico) median la respuesta conductual, y sugerimos que deben ser integrados al manejo a nivel de ecosistema y en la planificación espacial de actividades humanas cerca de las costas.
ObjectivesTo evaluate the effectiveness of hearing conservation programs (HCP) and their specific components in reducing noise-induced hearing loss (NIHL).MethodsThis retrospective cohort study was ...conducted at one food-processing plant and two automotive plants. Audiometric and work-history databases were combined with historical noise monitoring data to develop a time-dependent exposure matrix for each plant. Historical changes in production and HCP implementation were collected from company records, employee interviews and focus groups. These data were used to develop time-dependent quality assessments for various HCP components. 5478 male (30 427 observations) and 1005 female (5816 observations) subjects were included in the analysis.ResultsAnalyses were conducted separately for males and females. Females tended to have less NIHL at given exposure levels than males. Duration of noise exposure stratified by intensity (dBA) was a better predictor of NIHL than the standard equivalent continuous noise level (Leq) based upon a 3-dBA exchange. Within this cohort, efficient dBA strata for males were <95 versus ≥95, and for females <90 versus ≥90. The reported enforced use of hearing protection devices (HPDs) significantly reduced NIHL. The data did not have sufficient within-plant variation to determine the effectiveness of noise monitoring or worker training. An association between increased audiometric testing and NIHL was believed to be an artifact of increased participation in screening.ConclusionsHistorical audiometric data combined with noise monitoring data can be used to better understand the effectiveness of HCPs. Regular collection and maintenance of quality data should be encouraged and used to monitor the effectiveness of these interventions.
An increasing number of original studies suggested that occupational noise exposure might be associated with the risk of hypertension, but the results remain inconsistent and inconclusive. In ...addition, the attributable fraction (AF) of occupational noise exposure has not been well quantified. We aimed to conduct a large-scale occupational population-based study to comprehensively investigate the relationship between occupational noise exposure and blood pressure and different hypertension subtypes and to estimate the AF for hypertension burden attributable to occupational noise exposure.
A total of 715,135 workers aged 18-60 years were included in this study based on the Key Occupational Diseases Surveillance Project of Guangdong in 2020. Multiple linear regression was performed to explore the relationships of occupational noise exposure status, the combination of occupational noise exposure and binaural high frequency threshold on average (BHFTA) with systolic and diastolic blood pressure (SBP, DBP). Multivariable logistic regression was used to examine the relationshipassociation between occupational noise exposure status, occupational noise exposure combined with BHFTA and hypertension. Furthermore, the attributable risk (AR) was calculated to estimate the hypertension burden attributed to occupational exposure to noise.
The prevalence of hypertension among occupational noise-exposed participants was 13·7%. SBP and DBP were both significantly associated with the occupational noise exposure status and classification of occupational noise exposure combined with BHFTA in the crude and adjusted models (all P < 0·0001). Compared with workers without occupational noise exposure, the risk of hypertension was 50% greater among those exposed to occupational noise in the adjusted model (95% CI 1·42-1·58). For participants of occupational noise exposed with BHFTA normal, and occupational noise exposed with BHFTA elevated, the corresponding risks of hypertension were 48% (1·41-1·56) and 56% (1·46-1·63) greater than those of occupational noise non-exposed with BHFTA normal, respectively. A similar association was found in isolated systolic hypertension (ISH) and prehypertension. Subgroup analysis by sex and age showed that the positive associations between occupational noise exposure and hypertension remained statistically significant across all subgroups (all P < 0.001). Significant interactions between occupational noise status, classification of occupational noise exposure combined with BHFTA, and age in relation to hypertension risk were identified (all P for interaction < 0.001). The associations of occupational noise status, classification of occupational noise exposure combined with BHFTA and hypertension were most pronounced in the 18-29 age groups. The AR% of occupational noise exposure for hypertension was 28·05% in the final adjusted model.
Occupational noise exposure was positively associated with blood pressure levels and the prevalence of hypertension, ISH, and prehypertension in a large occupational population-based study. A significantly increased risk of hypertension was found even in individuals with normal BHFTA exposed to occupational noise, with a further elevated risk observed in those with elevated BHFTA. Our findings provide epidemiological evidence for key groups associated with occupational noise exposure and hypertension, and more than one-fourth of hypertension cases would have been prevented by avoiding occupational noise exposure.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fractional-Formula Omitted phase-locked loop frequency synthesizers based on time-to-digital converters (TDC-PLLs) have been proposed to reduce the area and linearity requirements of conventional ...PLLs based on delta-sigma modulation and charge pumps (Formula Omitted-PLLs). Although TDC-PLLs with good performance have been demonstrated, TDC quantization noise has so far kept their phase noise and spurious tone performance below that of the best comparable Formula Omitted-PLLs. An alternative approach is to use a delta-sigma frequency-to-digital converter (Formula Omitted FDC) in place of a TDC to retain the benefits of TDC-PLLs and Formula Omitted-PLLs. This paper proposes a practical Formula Omitted FDC based PLL in which the quantization noise is equivalent to that of a Formula Omitted-PLL. It presents a linearized model of the PLL, design criteria to avoid spurious tones in the Formula Omitted FDC quantization noise, and a design methodology for choosing the loop parameters in terms of standard PLL target specifications.
Noise Exposure and Public Health Passchier-Vermeer, Willy; Passchier, Wim F.
Environmental health perspectives,
03/2000, Letnik:
108, Številka:
Suppl 1
Journal Article
Recenzirano
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Exposure to noise constitutes a health risk. There is sufficient scientific evidence that noise exposure can induce hearing impairment, hypertension and ischemic heart disease, annoyance, sleep ...disturbance, and decreased school performance. For other effects such as changes in the immune system and birth defects, the evidence is limited. Most public health impacts of noise were already identified in the 1960s and noise abatement is less of a scientific but primarily a policy problem. A subject for further research is the elucidation of the mechanisms underlying noise-induced cardiovascular disorders and the relationship of noise with annoyance and nonacoustical factors modifying health outcomes. A high priority study subject is the effects of noise on children, including cognitive effects and their reversibility. Noise exposure is on the increase, especially in the general living environment, both in industrialized nations and in developing world regions. This implies that in the twenty-first century noise exposure will still be a major public health problem.
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Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Sleep disturbances caused by noise exposure are the most relevant outcome measured in disability adjusted life years (DALYs). In analogy to the combined effects of noise from multiple sources on ...annoyance, these are also of interest for sleep disorders. The study “Overall Noise Assessment” Innsbruck examined data from 1031 personal interviews. Aircraft, rail and road noise were correlated. To choose participants combined exposures were clustered into small, medium and severely affected living situations. The effect of demographic features, noise sensitivity, access to a silent façade and other factors on self-reported sleep disturbances was investigated applying bivariate analyses. Exposure-response curves and their 95% confidence intervals with cut-off values of 72% for “highly disturbed sleep” were generated and the results were discussed in comparison to recently published curves. Using source-specific exposure-response relationships, an overall model for evaluating sleep disorders was developed based on the “annoyance equivalents model”. The “total sleep disturbance response” shows an accumulative outcome for each source measured. A protective effect of road traffic noise as background noise for air and railroad sources could not be proven. Both the “Total Sleep Disruption Assessment Model” and the “Dominant Source Model” have a Spearman-Rho of 0.3 and are therefore suitable for use in noise assessment.
Photon shot noise, arising from the quantum-mechanical nature of the light, currently limits the sensitivity of all the gravitational wave observatories at frequencies above one kilohertz. We report ...a successful application of squeezed vacuum states of light at the GEO 600 observatory and demonstrate for the first time a reduction of quantum noise up to 6.03±0.02 dB in a kilometer scale interferometer. This is equivalent at high frequencies to increasing the laser power circulating in the interferometer by a factor of 4. Achieving this milestone, a key goal for the upgrades of the advanced detectors required a better understanding of the noise sources and losses and implementation of robust control schemes to mitigate their contributions. In particular, we address the optical losses from beam propagation, phase noise from the squeezing ellipse, and backscattered light from the squeezed light source. The expertise gained from this work carried out at GEO 600 provides insight toward the implementation of 10 dB of squeezing envisioned for third-generation gravitational wave detectors.
Ring-oscillator (RO)-based phase-locked loops (PLLs) are very attractive for system-on-chip applications for their compactness and tuning range, but suffer from high jitter and supply noise ...sensitivity. This paper presents a sub-sampling phase detector (SSPD)-based feedforward noise cancellation (FFNC) technique to improve these drawbacks of the RO PLL. The FFNC scheme utilizes the already available SSPD output to perform cancellation with high sensitivity while utilizing low power and area overhead. The 2- to 2.8-GHz RO PLL proof-of-principle prototype occupies 0.022 mm 2 active area in 65 nm CMOS; it achieves a 633 fs rms jitter at 2.36 GHz with 5.86 mW power consumption and an figure of merit (FOM jitter ) of -236.3 dB. The cancellation reduces the jitter by 1.4×, the phase noise by 10.2 dB to -123.5 dBc/Hz at 300-kHz offset, and the RO supply sensitivity by 19.5 dB for a 1 mVpp 100-kHz noise tone on the RO supply.
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