Urban noise distributions and the influence of geometric spreading on skewness

2021 ◽  
Author(s):  
D. Wilson ◽  
Matthew Kamrath ◽  
Caitlin Haedrich ◽  
Daniel Breton ◽  
Carl Hart
Keyword(s):  
Traffic Noise ◽  
Temporal Variations ◽  
Sound Level ◽  
Noise Sources ◽  
Urban Noise ◽  
Broad Perspective ◽  
Source Power ◽  
The North ◽  
Leibler Divergence ◽  
Geometric Spreading

Statistical distributions of urban noise levels are influenced by many complex phenomena, including spatial and temporal variations in the source level, multisource mixtures, propagation losses, and random fading from multipath reflections. This article provides a broad perspective on the varying impacts of these phenomena. Distributions incorporating random fading and averaging (e.g., gamma and noncentral Erlang) tend to be negatively skewed on logarithmic (decibel) axes but can be positively skewed if the fading process is strongly modulated by source power variations (e.g., compound gamma). In contrast, distributions incorporating randomly positioned sources and explicit geometric spreading [e.g., exponentially modified Gaussian (EMG)] tend to be positively skewed with exponential tails on logarithmic axes. To evaluate the suitability of the various distributions, one-third octave band sound-level data were measured at 37 locations in the North End of Boston, MA. Based on the Kullback-Leibler divergence as calculated across all of the locations and frequencies, the EMG provides the most consistently good agreement with the data, which were generally positively skewed. The compound gamma also fits the data well and even outperforms the EMG for the small minority of cases exhibiting negative skew. The lognormal provides a suitable fit in cases in which particular non-traffic noise sources dominate.

scholarly journals The influence of a signal’s time structure on the perceived noise annoyance of road traffic noise

2021 ◽  
Author(s):  
Jan Felcyn
Keyword(s):  
Road Traffic ◽  
Temporal Structure ◽  
Traffic Noise ◽  
Sound Level ◽  
Time Structure ◽  
Common Source ◽  
Road Traffic Noise ◽  
Noise Annoyance ◽  
Modern Cities ◽  
Negative Feelings

Abstract Purpose Road traffic noise is the most common source of noise in modern cities. The noise indicators used to manage noise do not take into account its temporal structure. However, in cities the traffic flow varies during the day, peaking due to congestion and more fluent periods. In this research we sought to analyze how people (giving answers on a numerical ICBEN scale) perceive noise stimuli with the same LAeqT values but different time structures (more/less noise events, different amplitude envelopes). Methods 31 people with normal hearing took part in an experiment conducted in an anechoic chamber. Participants listened to 18 different noise recordings and rated each of them using the numerical ICBEN scale regarding noise annoyance. Results The results showed that only sound level was a statistically significant factor. However, based on people’s remarks about noise, we can also say that the more intermittent the noise is, the more negative feelings it evokes in people. Conclusions Time structure does not have a significant influence on people’s judgments about noise annoyance. However, people tend to have a preference for a steady noise rather than an intermittent one.

Sierra Nevada-Great Basin boundary zone: Earthquake hazard related to structure, active tectonic processes, and anomalous patterns of earthquake occurrence

1980 ◽  
Vol 70 (5) ◽  
pp. 1557-1572
Author(s):  
J. D. VanWormer ◽  
Alan S. Ryall
Keyword(s):  
Sierra Nevada ◽  
Great Basin ◽  
Temporal Variations ◽  
Mono Lake ◽  
Local Network ◽  
Low Velocity ◽  
Owens Valley ◽  
Walker Lake ◽  
Fault Plane Solutions ◽  
The North

abstract Precise epicentral determinations based on local network recordings are compared with mapped faults and volcanic features in the western Great Basin. This region is structurally and seismically complex, and seismogenic processes vary within it. In the area north of the rupture zone of the 1872 Owens Valley earthquake, dispersed clusters of epicenters agree with a shatter zone of faults that extend the 1872 breaks to the north and northwest. An area of frequent earthquake swarms east of Mono Lake is characterized by northeast-striking faults and a crustal low-velocity zone; seismicity in this area appears to be related to volcanic processes that produced thick Pliocene basalt flows in the Adobe Hills and minor historic activity in Mono Lake. In the Garfield Hills between Walker Lake and the Excelsior Mountains, there is some clustering of epicenters along a north-trending zone that does not correlate with major Cenozoic structures. In an area west of Walker Lake, low seismicity supports a previous suggestion by Gilbert and Reynolds (1973) that deformation in that area has been primarily by folding and not by faulting. To the north, clusters of earthquakes are observed at both ends of a 70-km-long fault zone that forms the eastern boundary of the Sierra Nevada from Markleeville to Reno. Clusters of events also appear at both ends of the Dog Valley Fault in the Sierra west of Reno, and at Virginia City to the east. Fault-plane solutions for the belt in which major earthquakes have occurred in Nevada during the historic period (from Pleasant Valley in the north to the Excelsior Mountains on the California-Nevada Border) correspond to normaloblique slip and are similar to that found by Romney (1957) for the 1954 Fairview Peak shock. However, mechanisms of recent moderate earthquakes within the SNGBZ are related to right- or left-lateral slip, respectively, on nearly vertical, northwest-, or northeast-striking planes. These mechanisms are explained by a block faulting model of the SNGBZ in which the main fault segments trend north, have normal-oblique slip, and are offset or terminated by northwest-trending strike-slip faults. This is supported by the observation that seismicity during the period of observation has been concentrated at places where major faults terminate or intersect. Anomalous temporal variations, consisting of a general decrease in seismicity in the southern part of the SNGBZ from October 1977 to September 1978, followed by a burst of moderate earthquakes that has continued for more than 18 months, is suggestive of a pattern that several authors have identified as precursory to large earthquakes. The 1977 to 1979 variations are particularly noteworthy because they occurred over the entire SNGBZ, indicating a regional rather than local cause for the observed changes.

scholarly journals Frequency-dependent noise sources in the North Atlantic Ocean

2013 ◽  
Vol 14 (12) ◽  
pp. 5341-5353 ◽  
Author(s):  
Amandine Sergeant ◽  
Eléonore Stutzmann ◽  
Alessia Maggi ◽  
Martin Schimmel ◽  
Fabrice Ardhuin ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Noise Sources ◽  
Frequency Dependent ◽  
The North ◽  
The North Atlantic

scholarly journals Level and Noise Sources in the Neonatal Intensive Care Unit of a Reference Hospital

2020 ◽  
Vol 38 (3) ◽  
Author(s):  
Alma Damaris Hernández-Salazar ◽  
Josefina Gallegos-Martínez ◽  
Jaime Reyes-Hernández
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Neonatal Intensive Care Unit ◽  
Neonatal Intensive Care ◽  
Environmental Noise ◽  
Sound Level ◽  
Noise Sources ◽  
Cross Sectional ◽  
Reference Hospital ◽  
And Shifts

Objective. Determine the level of environmental and periauricular noise in preterm babies and identify the sources generating noise in the Neonatal Intensive Care Unit -NICU- of a reference hospital in San Luis Potosí, Mexico. Methods. Cross-sectional and analytic study of the measurement of the level of environmental noise in five critical areas of the NICU, according with the method of measurement of noise from fixed sources by the Mexican Official Norm and periauricular at 20 cm from the preterm patient’s pinna. The measurements were carried out during three representative days of a week,morning, evening and nocturnal shifts. A STEREN 400 sound level meter was used with 30 to 130 dB range of measurement and a rate of 0.5 s. Results. The average level of periauricular noise (64.5±1.91dB) was higher than the environmental noise (63.3±1.74 dB) during the days and shifts evaluated. The principal noise sources were activities carried out by the staff, like the nursing change of shift and conversations by the staff, which raised the level continuously or intermittently, operation of vital support equipment (alarms) and incidences (clashing of baby bottles and moving furnishings) producedsudden rises of noise. Conclusions. Environmental and periauricular noise in NICU exceeds by two and almost three times the 45 dB during the day and 35 dB at night from the norm in hospitals. It is necessary to implement permanent noise reduction programs to prevent sequelae in the preterm infant and professional burnout in the nursing staff.

scholarly journals ICHTHYOFAUNA IN THE INNER CONTINENTAL SHELF NEXT TO THE PARANAGUÁ ESTUARINE COMPLEX, SOUTHERN BRAZIL

2021 ◽  
Vol 46 (4) ◽  
pp. 1-13
Author(s):  
Cesar SANTOS ◽  
Roberto SCHWARZ JUNIOR ◽  
Helen Audrey PICHLER ◽  
Olímpio Rafael CARDOSO ◽  
Marcelo Renato LAMOUR ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Fish Assemblages ◽  
Fish Fauna ◽  
Temporal Variations ◽  
Otter Trawl ◽  
Rainfall Regime ◽  
Wet Season ◽  
Environmental Characteristics ◽  
The North ◽  
Inner Continental Shelf

The composition and structure of fish assemblages in the inner continental shelf of the Paraná State are affected by cold fronts and the rainfall regime. Data from fishing activities in this region, as well as the analysis of environmental characteristics, are the main tools available for understanding fish dynamics, under influence of increasing human activities. In order to better understand patterns and temporal variations in fish assemblages in the inner continental shelf of the Paraná State, a total of 24 double trawls were performed with an otter trawl between August 2000 and July 2001, in two sampling areas, the North area in front of the northern mouth of the Paranaguá Estuary Complex, and the South area, in front of the Leste beach. A total of 45,277 fish specimens belonging to 35 families and 97 species were caught. Sciaenidae was the most abundant family, with 37.1% of the total number of individuals caught, and with the highest richness (18 species). Statistical analyses evidenced significant differences in environmental characteristics and in fish fauna, and that both areas disturbances were observed in the fish assemblages during the dry and wet season, being more intense in the Southern area, disturbances that would be related to the shrimp fishing present in the two areas sampled in this study.

scholarly journals INFRASOUND AND LOW FREQUENCY NOISE IMMISION FROM PIPELINES. iMPROVING THE ISO 1996-2:2017 PROPOSED METHODS. CASES STUDIES CONDUCTED AT LOS ANDES AND PERUVIAN RAINFOREST

Akustika ◽  
2019 ◽  
Vol 32 ◽  
pp. 335-345
Author(s):  
Walter Montano
Keyword(s):  
Low Frequency ◽  
Sound Level ◽  
Frequency Noise ◽  
Gas Extraction ◽  
Howler Monkeys ◽  
Noise Sources ◽  
Industrial Facilities ◽  
Sound Levels ◽  
Continuous Noise ◽  
Amazonian Rainforest

The gas extraction wells are in Amazonian rainforest and by them there are their industrial facilities. The pipeline has about 800 km with four pumps stations and two compressor stations. The challenge of conducting sound measurements was important-there is no specialized literature-and other noise "sources" are howler monkeys, cicadidae chirping, woodpeckers, trees´foliage, etc. However the problem is simply because those fixed industrial facilities are the only ones. People live in isolated hamlet on the side of dirt roads, so they are exposed 24/7 to the continuous noise; at homes 4 km away from the plants the sound level is 60 dBC, but in the spectrum of ILFN tones could not be identified. This Paper presents the procedures that were developed to identify the ILFN tones, improving the methods proposed in ISO 1996-2, writing a software that "automatically eliminates" the sound levels that don´t belong to the industry,

scholarly journals Learning to cope: vocal adjustment to urban noise is correlated with prior experience in black-capped chickadees

2016 ◽  
Vol 283 (1833) ◽  
pp. 20161058 ◽  
Author(s):  
Stefanie E. LaZerte ◽  
Hans Slabbekoorn ◽  
Ken A. Otter
Keyword(s):  
Ambient Noise ◽  
Prior Experience ◽  
Traffic Noise ◽  
Experimental Studies ◽  
Previous Exposure ◽  
Poecile Atricapillus ◽  
Urban Noise ◽  
Experimental Noise ◽  
Avian Communication ◽  
The City

Urban noise can interfere with avian communication through masking, but birds can reduce this interference by altering their vocalizations. Although several experimental studies indicate that birds can rapidly change their vocalizations in response to sudden increases in ambient noise, none have investigated whether this is a learned response that depends on previous exposure. Black-capped chickadees ( Poecile atricapillus ) change the frequency of their songs in response to both fluctuating traffic noise and experimental noise. We investigated whether these responses to fluctuating noise depend on familiarity with noise. We confirmed that males in noisy areas sang higher-frequency songs than those in quiet areas, but found that only males in already-noisy territories shifted songs upwards in immediate response to experimental noise. Unexpectedly, males in more quiet territories shifted songs downwards in response to experimental noise. These results suggest that chickadees may require prior experience with fluctuating noise to adjust vocalizations in such a way as to minimize masking. Thus, learning to cope may be an important part of adjusting to acoustic life in the city.

scholarly journals Measuring the Vertical Profiles of Aerosol Extinction in the Lower Troposphere by MAX-DOAS at a Rural Site in the North China Plain

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1037
Author(s):  
Siyang Cheng ◽  
Junli Jin ◽  
Jianzhong Ma ◽  
Xiaobin Xu ◽  
Liang Ran ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Lower Troposphere ◽  
Temporal Variations ◽  
Rural Site ◽  
Optical Absorption Spectroscopy ◽  
Aerosol Extinction ◽  
Vertical Profiles ◽  
Near Surface ◽  
The North

Ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements were performed during the summer (13 June–20 August) of 2014 at a rural site in North China Plain. The vertical profiles of aerosol extinction (AE) in the lower troposphere were retrieved to analyze the temporal variations of AE profiles, near-surface AE, and aerosol optical depth (AOD). The average AOD and near-surface AE over the period of study were 0.51 ± 0.26 and 0.33 ± 0.18 km−1 during the effective observation period, respectively. High AE events and elevated AE layers were identified based on the time series of hourly AE profiles, near-surface AEs and AODs. It is found that in addition to the planetary boundary layer height (PBLH) and relative humidity (RH), the variations in the wind field have large impacts on the near-surface AE, AOD, and AE profile. Among 16 wind sectors, higher AOD or AE occur mostly in the directions of the cities upstream. The diurnal variations of the AE profiles, AODs and near-surface AEs are significant and influenced mainly by the source emissions, PBLH, and RH. The AE profile shape from MAX-DOAS measurement is generally in agreement with that from light detection and ranging (lidar) observations, although the AE absolute levels are different. Overall, ground-based MAX-DOAS can serve as a supplement to measure the AE vertical profiles in the lower troposphere.

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