Incubator Noise

PEDIATRICS ◽  
1975 ◽  
Vol 56 (4) ◽  
pp. 617-617
Author(s):  
Gōsta Blennow ◽  
Nils W. Svenningsen ◽  
Bengt Almquist
Keyword(s):  
Low Frequency ◽  
Sound Level ◽  
Noise Levels ◽  
Frequency Sound ◽  
Mechanical Noise ◽  
Sound Levels ◽  
Infant Incubator ◽  
Improved Model ◽  
Model C

Recently we reported results from studies of incubator noise levels.1 It was found that in certain types of incubators the noise was considerable, and attention was called to the sound level in the construction of new incubators. Recently we had the opportunity to study an improved model of Isolette Infant Incubator Model C-86 where the mechanical noise from the electrically powered motor has been partially eliminated. With this modification it has been possible to lower the low-frequency sound levels to a certain degree in comparison to the levels registered in our study.

Ground Attenuation Factor Based on Measurements

2021 ◽  
Vol 263 (3) ◽  
pp. 3436-3447
Author(s):  
Dan Lin ◽  
Andrew Eng
Keyword(s):  
Near Field ◽  
Attenuation Factor ◽  
Measurement Data ◽  
Low Frequency ◽  
Sound Sources ◽  
Frequency Sound ◽  
Sound Levels ◽  
Different Types ◽  
Noise Measurements ◽  
Field Sound

Assumptions made on the ground types between sound sources and receivers can significantly impact the accuracy of environmental outdoor noise prediction. A guideline is provided in ISO 9613-2 and the value of ground factor ranges from 0 to 1, depending on the coverage of porous ground. For example, a ground absorption factor of 1 is suggested for grass ground covers. However, it is unclear if the suggested values are validated. The purpose of this study is to determine the sound absorption of different types of ground by measurements. Field noise measurements were made using an omnidirectional loudspeaker and two microphones on three different types of ground in a quiet neighborhood. One microphone was located 3ft from the loudspeaker to record near field sound levels in 1/3 and 1 octave bands every second. The other microphone was located a few hundred feet away to record far field sound in the same fashion as the near field microphone. The types of ground tested were concrete, grass, and grass with trees. Based on the measurement data, it was found that grass and trees absorb high frequency sound well and a ground factor of 1 may be used for 500Hz and up when using ISO 9613-2 methodology. However, at lower frequencies (125 Hz octave band and below), grassy ground reflects sound the same as concrete surfaces. Trees absorb more low frequency sound than grass, but less than ISO 9613-2 suggested.

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 Appraisal of Noise Level Dissemination Surrounding Mining and Industrial Areas of Keonjhar, Odisha: a Comprehensive Approach Using Noise Mapping

2017 ◽  
Vol 42 (3) ◽  
pp. 423-432 ◽  
Author(s):  
Satish K. Lokhande ◽  
Satyajeet A. Dhawale ◽  
Samir S. Pathak ◽  
Rakesh Gautam ◽  
Mohindra C. Jain ◽  
...  
Keyword(s):  
Noise Level ◽  
Sound Level ◽  
Noise Levels ◽  
Night Time ◽  
Noise Mapping ◽  
High Noise ◽  
Sensitive Areas ◽  
Sound Levels ◽  
Directorate General ◽  
Open Cast

Abstract Noise mapping is a well-established practice among the European nations, and it has been follow for almost two decades. Recently, as per guidelines of the Directorate General of Mines Safety (DGMS), India, noise mapping has been made mandatory in the mining expanses. This study is an effort to map the noise levels in nearby areas of mines in the northern Keonjhar district. The motive of this study is to quantify the existing A-weighted time-average sound level (LAeq,T ) in the study area to probe its effects on the human dwellings and noise sensitive areas with the probability of future development of the mines, roads, and industrial and commercial zone. The LAeq,T was measured at 39 identified locations, including industrial, commercial, residential, and sensitive zones, 15 open cast mines, 3 major highways, and 3 haulage roads. With the utilisation of Predictor LimA Software and other GIS tools, the worked out data is mapped and noise contours are developed for the visualisation and identification of the extent and distribution of sound levels across the study area. This investigation discloses that the present noise level at 60% of the locations in silence and residential zone exposed to significantly high noise levels surpasses the prescribed limit of Central Pollution Control Board (CPCB), India. The observed day and night time LAeq, T level of both zones ranged between 43.2-62.2 dB(A) and 30.5-53.4 dB(A), respectively, whereas, the average Ldn values vary between 32.7 and 51.2 dB(A). The extensive mobility of heavy vehicles adjoining the sensitive areas and a nearby plethora of open cast mines is the leading cause of exceeded noise levels. The study divulges that the delicate establishments like schools and hospitals are susceptible to high noise levels throughout the day and night. A correlation between observed and software predicted values gives R2 of 0.605 for Ld, 0.217 for Ln, and 0.524 for Ldn. Finally, the mitigation measure is proposed and demonstrated using a contour map showing a significant reduction in the noise levels by 0-5.3 dB(A).

scholarly journals Low-frequency sound level in the Southern Indian Ocean

2015 ◽  
Vol 138 (6) ◽  
pp. 3439-3446 ◽  
Author(s):  
Eve Tsang-Hin-Sun ◽  
Jean-Yves Royer ◽  
Emmanuelle C. Leroy
Keyword(s):  
Indian Ocean ◽  
Low Frequency ◽  
Sound Level ◽  
Southern Indian Ocean ◽  
Frequency Sound

scholarly journals Noise risk assessment in a bottling line of a modern Sicilian winery

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Mariangela Vallone ◽  
Felice Pipitone ◽  
Salvatore Amoroso ◽  
Pietro Catania
Keyword(s):  
Noise Level ◽  
Sound Level ◽  
Wine Industry ◽  
Production Cycle ◽  
Working Capacity ◽  
Noise Levels ◽  
Test Conditions ◽  
Sound Levels ◽  
Class 1 ◽  
Plant Area

In wine industry, bottling is a phase of the production cycle characterized by high levels of noise mostly due to repeated collisions between the bottles. In Italy the Law Decree 81/2008 defined the requirements for assessing and managing noise risk, identifying a number of procedures to be adopted at different noise levels to limit workers exposure. This study aims at evaluating the equivalent and peak noise level inside the bottling plant area of a modern Sicilian winery. In particular, the influence of the working capacity (number of bottles produced per hour) on noise levels was evaluated. We considered three test conditions: T1 with working capacity of 4,000 bottles per hour, T2 with working capacity of 5,000 bottles per hour and T3 with working capacity of 6,000 bottles per hour. Fifteen measurement points were identified inside the bottling area. The instrument used for the measurements is a precision integrating portable sound level meter, class 1, model HD2110L by Delta OHM, Italy. The tests were performed in compliance with ISO 9612 and ISO 9432 regulations. The results show that as bottling plant working capacity increases, noise level increases. The measured sound levels exceed the limits allowed by the regulations in all the test conditions; values exceeding the threshold limit of 80 dB(A) were recorded coming up to a maximum value of 95 dB(A) in test T3. In this case, the operator working along the bottling line is obliged to wear the appropriate Personal Protective Equipment.

scholarly journals How Can Low-Frequency Noise Exposure Interact with the Well-Being of a Population? Some Results from a Portuguese Municipality

2019 ◽  
Vol 9 (24) ◽  
pp. 5566 ◽  
Author(s):  
Juliana Araújo Alves ◽  
Lígia Torres Silva ◽  
Paula Remoaldo
Keyword(s):  
Urban Areas ◽  
Noise Exposure ◽  
Low Frequency ◽  
Noise Pollution ◽  
Well Being ◽  
Sound Level ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Sound Levels ◽  
Exposed Population

Noise pollution is the second most harmful environmental stressor in Europe. Portugal is the fourth European country most affected by noise pollution, whereby 23.0% of the population is affected. This article aims to analyze the effects of exposure to low frequency noise pollution, emitted by power poles and power lines, on the population’s well-being, based on a study of “exposed” and “unexposed” individuals in two predominantly urban areas in north-western Portugal. To develop the research, we used sound level (n = 62) and sound recording measurements, as well as adapted audiometric test performance (n = 14) and surveys conducted with the resident population (n = 200). The sound levels were measured (frequency range between 10 to 160 Hz) and compared with a criterion curve developed by the Department for Environment, Food and Rural Affairs (DEFRA). The sound recorded was performed 5 m away from the source (400 kV power pole). Surveys were carried out with the “exposed” and “unexposed” populations, and adapted audiometric tests were performed to complement the analysis and to determine the threshold of audibility of “exposed” and “unexposed” volunteers. The “exposed” area has higher sound levels and, consequently, more problems with well-being and health than the “unexposed” population. The audiometric tests also revealed that the “exposed” population appears to be less sensitive to low frequencies than the “unexposed” population.

Decibel levels during extracorporeal lithotripsy for salivary stones

2008 ◽  
Vol 122 (12) ◽  
pp. 1305-1308 ◽  
Author(s):  
M H Fritsch
Keyword(s):  
Human Perception ◽  
Patient Survey ◽  
Acoustic Trauma ◽  
Sound Level ◽  
Sound Level Meter ◽  
Noise Levels ◽  
Sound Levels ◽  
Extracorporeal Lithotripsy ◽  
Level Meter ◽  
Cross Reference

AbstractPurpose:To determine the decibel sound pressure levels generated during extracorporeal lithotripsy for salivary stones, and if such lithotriptor noise levels have the potential for acoustic trauma.Patients and materials:Minilith SL-1 salivary gland lithotriptor, sound level meter; five patient survey.Methods:Decibel measurements were conducted on the lithotripter-generated sounds, using a sound level meter at specific distances from the active element. In addition, a patient survey was conducted as a cross-reference, to enable comparison of predicted results with actual human perception of sound levels.Results:Sound levels ranged between 68 and 80 dB during treatment sessions, for both the lithotriptor operator and the patient.Conclusion:During routine use, no acoustic trauma is incurred by either the lithotriptor operator or the patient.

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