A simple ocean noise exposure metric based on naturally occurring noise levels and biological thresholds

2007 ◽  
Vol 122 (5) ◽  
pp. 3002
Author(s):  
Michael Stocker ◽  
Tom Reuterdahl ◽  
Libbie Horn ◽  
Gail Hurley
Keyword(s):  
Noise Exposure ◽  
Noise Levels ◽  
Naturally Occurring ◽  
Ocean Noise

Damage Risk: An Evaluation of the Effects of Exposure to 85 versus 90 dBA of Noise

1976 ◽  
Vol 19 (2) ◽  
pp. 216-224 ◽  
Author(s):  
James T. Yates ◽  
Jerry D. Ramsey ◽  
Jay W. Holland
Keyword(s):  
White Noise ◽  
Statistical Difference ◽  
Noise Exposure ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Noise Levels ◽  
Potential Damage ◽  
Full Day ◽  
Damage Risk

The purpose of this study was to compare the damage risk of 85 and 90 dBA of white noise for equivalent full-day exposures. The damage risk of the two noise levels was determined by comparing the temporary threshold shift (TTS) of 12 subjects exposed to either 85 or 90 dBA of white noise for equivalent half- and full-day exposures. TTS was determined by comparing the pre- and postexposure binaural audiograms of each subject at 1, 2, 3, 4, 6, and 8 kHz. It was concluded that the potential damage risk, that is, hazardous effect, of 90 dBA is greater than 85 dBA of noise for equivalent full-day exposures. The statistical difference between the overall effects of equivalent exposures to 85 dBA as compared to 90 dBA of noise could not be traced to any one frequency. The damage risk of a full-day exposure to 85 dBA is equivalent to that of a half-day exposure to 90 dBA of noise. Within the limits of this study, TTS t was as effective as TTS 2 for estimating the damage risk of noise exposure.

Aircraft Noise Levels, Annoyance and General Health of Residents of Communities contiguous to a Major Airport in Lagos State

2020 ◽  
Vol 8 (4) ◽  
pp. 47-59
Author(s):  
Iheanyichukwu M. Elechi
Keyword(s):  
Health Status ◽  
General Health ◽  
Noise Exposure ◽  
Aircraft Noise ◽  
Poor Health ◽  
Noise Levels ◽  
General Health Status ◽  
Lagos State ◽  
Distant Location ◽  
Self Reported Health Status

The purpose of this study was to investigate the relationship between the aircraft noise exposure, annoyance reactions and health status of the residents living within the vicinity of the Murtala Muhammed International Airport (MMA) in Lagos state, Nigeria. Aircraft noise monitoring was conducted in five locations within the vicinity (0-5Km) of MMA, and a sixth distant location (14km away). Levels of aircraft noise for all five locations within the vicinity of the airport exceeded the EPA Victoria threshold of 75 dB LAmax for the residential area (outdoor). A survey on annoyance induced by aircraft noise exposure and general health status was conducted on 450 local residents in the study locations using the International Commission on Biological Effect of Noise question and a single question that has been applied in Dutch national health care surveys since 1983 on self-reported general health status respectively. Percentage of residents within the vicinity of MMA that were highly annoyed (%HA) exceeded 15% guideline limit stipulated by Federal Interagency Committee on Urban Noise while 14.5% reported poor health status. There was a significant association between the annoyance reactions and aircraft noise levels in the study locations while the association between self-reported health status and aircraft noise levels was not significant. Taken together, the residents within the vicinity of the airport are exposed to aircraft noise levels above permissible limit which may be associated with high annoyance reaction but may not be associated with poor health rating. Evidence-based aircraft noise related policies by government are advocated.

scholarly journals 303 What goes bump in the night? A literature review and noise exposure experiment in a UK paediatric emergency department

2020 ◽  
Vol 37 (12) ◽  
pp. 841.1-841
Author(s):  
Lucy Hall ◽  
Sophie Dando ◽  
Anthony Hanks
Keyword(s):  
Emergency Department ◽  
Literature Review ◽  
Literature Search ◽  
Noise Exposure ◽  
Cochrane Library ◽  
Noise Levels ◽  
Paediatric Emergency Department ◽  
Paediatric Emergency ◽  
Sound Levels ◽  
Exposure Experiment

Aims/Objectives/BackgroundIn the Emergency department (ED), noise is a frequent and often unavoidable consequence of work undertaken and levels can often be raised during the day and night. Raised ambient noise levels have potential implications for the workforce, patients and relatives.Investigation into the problem of noise levels in the ED follows feedback from a young patient who couldn’t sleep during a prolonged stay. His complaint focused on loud, irregular banging noises such as those from closing bins that kept him awake.The team felt work should be done to see if it was a wider spread problem or just isolated to his case. A simple sound recording experiment and literature search was conducted.Methods/DesignThe literature search was conducted using electronic/online databases (Medline; Cochrane library) with a fixed date range and specific inclusion criteria.The noise exposure experiment was conducted using a verified phone app to record the sound levels. They were measured at 3 times, during a night shift, in the paediatric emergency department of UHW. All measurements were at a fixed distance and were averaged and compared with WHO recommendations.Results/ConclusionsThere are many sources of noise pollution in the ED, some are unavoidable for safety and clinical reasons.The literature review produced a small number of papers all of which found that sound levels were raised above recommended levels. Similarly, all the sounds measured in the ED also exceeded the recommendations.The most consistent finding across the papers, matched by findings from recordings, was that human behavioural modification is an easy and effective way to reduce noise levels.There are simple steps that can be taken to reduce and eliminate soundsRaising awareness regarding this problem is of great importance and focussing future work on assessing the impact in younger patients within the Emergency Department is paramount.

scholarly journals Case Study in a Working Environment Highlighting the Divergence between Sound Level and Workers’ Perception towards Noise

2020 ◽  
Vol 17 (17) ◽  
pp. 6122
Author(s):  
Chun-Yip Hon ◽  
Illia Tchernikov ◽  
Craig Fairclough ◽  
Alberto Behar
Keyword(s):  
Noise Exposure ◽  
Health And Safety ◽  
Sound Level ◽  
Working Environment ◽  
Noise Levels ◽  
Hearing Conservation ◽  
Attitudes And Perceptions ◽  
Noise Measurements ◽  
Survey Responses ◽  
Excessive Noise

Excessive noise levels are a prevalent issue in food processing operations and, although there have been numerous studies on occupational noise, no single study has used a concurrent mixed-methods approach. Employing this study design allows for an understanding of the level of convergence (similarity) between measured noise levels and workers’ attitudes and perceptions towards noise. This, in turn, allows for the identification of potential challenges with respect to the implementation of hearing conservation efforts. In this study, spot noise measurements were collected using a sound level meter. One-on-one interviews were conducted with workers to determine attitudes and perceptions towards noise in their workplaces. Subsequently, the results of the noise measurements (quantitative data) were integrated with the survey responses (qualitative data) to identify convergence. The majority of the noise measurements were found to exceed 85 dBA—the criterion mandated by the local occupational health and safety legislation. Although all study participants felt that it was noisy in the workplace, a large proportion of respondents indicated that the noise was not bothersome. With workers’ perception being contradictory to the measured noise levels, it is a challenge to implement hearing conservation measures unless changes are made to raise the awareness of the risks associated with excessive noise exposure.

Blow-Down Valve Noise and Interactions With Downstream Orifice Plates

2003 ◽  
Author(s):  
Denis G. Karczub ◽  
Fred W. Catron ◽  
Allen C. Fagerlund
Keyword(s):  
Noise Exposure ◽  
Control Valve ◽  
Low Noise ◽  
Noise Levels ◽  
Exposure Limits ◽  
Blow Down ◽  
Gas Processing ◽  
The Impact ◽  
Acoustic Fatigue ◽  
Infrequent Event

In a blow-down situation as might occur at a natural gas processing facility, noise levels are very high and significantly exceed the noise levels one would normally associate with a control valve. As the blow-down operation is an infrequent event, this may be permissible but requires consideration of the duration of these high noise levels to ensure that occupational noise exposure limits and acoustic fatigue limits are not exceeded. Tests of noise levels due to an 8-inch control valve in a 12-inch pipeline under blow-down conditions are compared here with noise level predictions based on the IEC standard. Consideration is also given to the impact of placing an orifice plate downstream of the control valve as is often done to reduce pressure drop across the valve in the expectation that control valve noise levels will be reduced. Simple orifice plates often installed by plant operators to achieve this goal are shown to have an adverse impact, and it is shown that a multi-hole diffuser or low-noise control valve should instead be used.

The variability of naturally occurring magnetic field levels: 10 Hz to 8 kHz

Geophysics ◽  
2010 ◽  
Vol 75 (6) ◽  
pp. F187-F197 ◽  
Author(s):  
Ben K. Sternberg
Keyword(s):  
Magnetic Field ◽  
Noise Level ◽  
Monsoon Season ◽  
Signal Frequency ◽  
Time Interval ◽  
Frequency Range ◽  
Noise Levels ◽  
Controlled Source ◽  
Naturally Occurring ◽  
Minimum Noise

The variability of naturally occurring magnetic fields in the frequency range from [Formula: see text] over a period of one year was studied. Contour plots for the [Formula: see text], [Formula: see text], and [Formula: see text] components and for frequencies of 10, 100, 1000, 2000, and 8000 Hz were produced. Average, minimum, maximum, and the standard deviations of these fields were also calculated for 12 distinctive time intervals. In the 1– to 8–kHz frequency range, the noise levels are typically higher at night. In the 10- to 100-Hz frequency range, the noise levels are typically higher during the day. During mid- to late-summer, there is frequent thunderstorm activity, known in the southwest United States as the monsoon season. The magnetic field levels are often very high during this time period. These variability ranges can be used to estimate the lowest levels of noise that may be encountered during field surveys, which iswhat the authors are looking for when running controlled-source electrical method surveys. These variability ranges can also be used to estimate the highest levels that may be encountered, which is what the authors are looking for when running natural-source electrical methods surveys, such as audio frequency magnetotelluric (AMT) surveys. These measurements of magnetic field strength variability show that better data for controlled-source electrical measurements can be obtained using the minimum noise level measurements, as opposed to using signal integration or signal averaging with all of the data. The minimum noise level is found by using frequency bins adjacent to the signal-frequency bin. Likewise, if one is interested in measuring the naturally occurring magnetic field data, using the maximum values during each time interval makes AMT measurements possible when the natural signal level is very low, particularly in the AMT dead zone around [Formula: see text].

S254 – Bone Conduction Noise Exposure via Ventilators in the NICU

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P160-P160
Author(s):  
Angela P Black ◽  
James D Sidman
Keyword(s):  
Ambient Noise ◽  
Noise Exposure ◽  
Bone Conduction ◽  
Sound Level ◽  
Noise Levels ◽  
High Noise ◽  
Endotracheal Tubes ◽  
Level Meter ◽  
Hearing Damage ◽  
Air Conduction

Objectives To demonstrate that neonatal ventilators produce high noise levels through bone conduction (BC) via endotracheal tubes, as well as air conduction (AC) from ambient noise. Methods A sound level meter was used to measure the noise levels 4 feet from the ventilator and in direct contact at the end of a balloon attached to the ETT to simulate the noise presented to the infant. 3 commonly used neonatal ventilators (Sensormedics 3100A, VIP Bird and Bunnell Jet) were examined. Results Noise levels were significantly higher (6 – 14 dB) at the end of the ETT than 4 ft from the ventilator for all ventilators studied. Conclusions Previous studies have shown high ambient noise levels in NICUs, but have failed to address the actual noise presented to the infant. ETT transmission of noise as a direct bone stimulus through the skull has been overlooked. This study has shown that high noise intensities are being presented not only as AC, but as BC to the infants though the ETT. This study demonstrates, therefore, that ear protection alone will not save these at-risk infants from hearing damage. More must be done to decrease noise exposure and develop quieter machines.

Combined effects of short-term noise exposure and hygrothermal conditions on indoor environmental perceptions

2017 ◽  
Vol 27 (8) ◽  
pp. 1119-1133 ◽  
Author(s):  
Wonyoung Yang ◽  
Hyeun Jun Moon ◽  
Myung-Jun Kim
Keyword(s):  
Gender Differences ◽  
Noise Exposure ◽  
Thermal Conditions ◽  
Combined Effects ◽  
Environmental Perceptions ◽  
Noise Levels ◽  
Short Term ◽  
Fan Noise ◽  
Subjective Assessments ◽  
Different Types

Realistic thermal conditions with various humidity levels have been considered to examine the combined effects of noise and thermal conditions on indoor environmental perceptions. Subjective assessments of temperature, humidity and psychoacoustics were conducted with 26 subjects under combined environments of seven thermal conditions (18℃: RH 30, 60%, 24℃: RH 27, 43, 65%, 30℃: RH 30, 60%), two noise types (fan and babble noises) and five noise levels (45, 50, 55, 60 and 65 dBA). Three-minute moderate noise exposure did not affect temperature or humidity sensations. However, the temperature and humidity levels affected loudness, annoyance and acoustic preferences when noise was presented as babble. Fan noise perceptions were found to be independent of thermal conditions. Gender differences were clearly found in terms of thermal and psychoacoustic perceptions. Men were more sensitive to hot sensations than women, and women were more sensitive to arid sensations than men. Women were more sensitive to noise levels than men. Gender differences were also found in terms of different types of noise. Men were found to be significantly less sensitive to fan noise than women. Even though psychoacoustic parameters were affected by indoor thermal conditions, thermal parameters were not affected by short-term moderate noise. The combined effect of various types of noise and temperature is still unclear, and this will be considered in a future larger cohort study.

Design of Generator Acoustic Blanket and its Impact on Generator Cooling Performance

2001 ◽  
Author(s):  
Wei Tong
Keyword(s):  
Sound Pressure ◽  
Noise Exposure ◽  
Cost Effective ◽  
Design Stage ◽  
Cooling Load ◽  
Noise Levels ◽  
Cooling Performance ◽  
Early Design Stage ◽  
Blanket Design ◽  
High Sound

Abstract Generator noise is one of the primary concerns in generator designs. The most cost-effective way to deal with the noise issue is to incorporate the reduction of sound pressure level in an early design stage. Once a generator is manufactured, it is often expensive to modify the design for reducing noise levels. For old generators with high sound pressure levels, an effective method to lower the generator noise exposure is to employ acoustic blankets wrapped on the generator external surfaces. However, with the application of acoustic blankets, heat transfer through generator walls can be greatly reduced, leading to the higher generator core temperature and higher generator cooling load. This paper has addressed the design of generator acoustic blankets and its impact on generator cooling performance. The analysis has shown that the influence of acoustic blankets on the generator thermal performance is low or moderate. This suggests that the current acoustic blanket design is feasible. Results from this study have been used to optimize the blanket design.

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