scholarly journals Characterization of Noise Level Inside a Vehicle under Different Conditions

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2471 ◽  
Author(s):  
Daniel Flor ◽  
Danilo Pena ◽  
Luan Pena ◽  
Vicente A. de Sousa ◽  
Allan Martins
Keyword(s):  
Regression Analysis ◽  
Noise Level ◽  
Acoustic Noise ◽  
Experimental Setup ◽  
Strongly Correlated ◽  
Noise Levels ◽  
Noise Sources ◽  
Statistical Tools ◽  
Window Position

Vehicular acoustic noise evaluations are a concern of researchers due to health and comfort effects on humans and are fundamental for anyone interested in mitigating audio noise. This paper focuses on the evaluation of the noise level inside a vehicle by using statistical tools. First, an experimental setup was developed with microphones and a microcomputer located strategically on the car’s panel, and measurements were carried out with different conditions such as car window position, rain, traffic, and car speed. Regression analysis was performed to evaluate the similarity of the noise level from those conditions. Thus, we were able to discuss the relevance of the variables that contribute to the noise level inside a car. Finally, our results revealed that the car speed is strongly correlated to interior noise levels, suggesting the most relevant noise sources are in the vehicle itself.

scholarly journals How did the ‘state of emergency’ declaration in Japan due to the COVID-19 pandemic affect the acoustic environment in a rather quiet residential area?

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Kimihiro Sakagami
Keyword(s):  
Noise Level ◽  
Residential Area ◽  
The State ◽  
Residential Areas ◽  
Noise Levels ◽  
Noise Sources ◽  
State Of Emergency ◽  
Acoustic Environment ◽  
Large Cities ◽  
City Centres

The COVID-19 pandemic caused lockdowns in many countries worldwide. Acousticians have made surveys to monitor how cities became quieter under the lockdown, mainly in central areas in cities. However, there have been few studies on the changes in the acoustic environment due to the pandemic in the usually quieter residential areas. It may be expected to be different from the effect in ‘originally noisy’ areas. Also, the effect could be different in Japan, because the ‘state of emergency’ declaration there was different to lockdowns elsewhere. Considering these circumstances, this article reports the results of noise monitoring and makes some observations on the acoustic environment in residential areas far from city centres, to provide an example of how the acoustic environment was affected by the state of emergency declaration due to the COVID-19 pandemic in Japan. The results showed that the reduction of noise levels was somewhat less than that reported in large cities. Also, comparing the results after the cancellation of the state of emergency, the noise level increased again. However, observations of noise sources imply that a possible change in human behaviour may have also affected the acoustic environment.

Global Active Noise Control of a One-Dimensional Acoustic Duct Using a Feedback Controller

1993 ◽  
Vol 115 (3) ◽  
pp. 488-494 ◽  
Author(s):  
A. J. Hull ◽  
C. J. Radcliffe ◽  
S. C. Southward
Keyword(s):  
Noise Level ◽  
Noise Control ◽  
Acoustic Noise ◽  
Active Noise Control ◽  
Decay Rates ◽  
Pole Placement ◽  
Noise Levels ◽  
One Dimensional ◽  
Active Noise ◽  
System Pressure

Active noise control of acoustic enclosures is a classical engineering problem. The active noise control of a one-dimensional hard-walled duct with a partially dissipative boundary condition is addressed in this paper. Previous techniques have attacked this problem by developing adaptive filters designed to cancel acoustic noise at a single measurement location. The work presented here applies modern, state space, control theory to globally reduce noise levels in a one-dimensional acoustic enclosure rather than at a single location. This global control requires only the addition of a single response measurement microphone and control speaker to the open-loop system. Pressure measurements are taken at the microphone location and passed to an observer, which generates estimates of the system states. Using these state estimates, a pole placement feedback control algorithm is used to lower the noise level. Pole placement reduces noise levels globally by increasing the decay rates of all the controlled acoustic states. Experimental results presented here demonstrate reduction in the noise level at all points in the duct by 58 percent when the system is excited by random amplitude pressure input.

scholarly journals How did "state of emergency" declaration in Japan due to the COVID-19 pandemic affect the acoustic environment in a rather quiet residential area?

2020 ◽  
Author(s):  
Kimihiro Sakagami
Keyword(s):  
Noise Level ◽  
Residential Area ◽  
The State ◽  
Residential Areas ◽  
Noise Levels ◽  
Noise Sources ◽  
State Of Emergency ◽  
Acoustic Environment ◽  
Large Cities ◽  
City Centres

The COVID-19 pandemic caused lockdown in many countries. Acousticians made surveys to monitor how cities became quieter under the lockdown, mainly in the central areas of cities. However, there have been few studies on changes in the acoustic environment due to the pandemic in rather quieter residential areas. It may be expected to be different from the effect in originally noisy areas. Also, the effect could be different in Japan, because the "state of emergency" declaration there was different to lockdown. Considering these circumstances, this paper reports the results of noise monitoring and makes some observations on the acoustic environment in residential areas remote from city centres, to provide an example of how the acoustic environment was affected by the "state of emergency" declaration due to the COVID-19 pandemic in Japan. The results showed that the reduction of noise levels was somewhat smaller than that reported in large cities. Also, comparing the results after the cancellation of the "state of emergency", the noise level increased again. However, observations of noise sources imply that a possible change in human behaviour may have also affected the acoustic environment.

scholarly journals How did "state of emergency" declaration in Japan due to the COVID-19 pandemic affect the acoustic environment in a rather quiet residential area?

2020 ◽  
Author(s):  
Kimihiro Sakagami
Keyword(s):  
Noise Level ◽  
Residential Area ◽  
The State ◽  
Residential Areas ◽  
Noise Levels ◽  
Noise Sources ◽  
State Of Emergency ◽  
Acoustic Environment ◽  
Large Cities ◽  
City Centres

The COVID-19 pandemic caused lockdown in many countries. Acousticians made surveys to monitor how cities became quieter under the lockdown, mainly in the central areas of cities. However, there have been few studies on changes in the acoustic environment due to the pandemic in rather quieter residential areas. It may be expected to be different from the effect in originally noisy areas. Also, the effect could be different in Japan, because the "state of emergency" declaration there was different to lockdown. Considering these circumstances, this paper reports the results of noise monitoring and makes some observations on the acoustic environment in residential areas remote from city centres, to provide an example of how the acoustic environment was affected by the "state of emergency" declaration due to the COVID-19 pandemic in Japan. The results showed that the reduction of noise levels was somewhat smaller than that reported in large cities. Also, comparing the results after the cancellation of the "state of emergency", the noise level increased again. However, observations of noise sources imply that a possible change in human behaviour may have also affected the acoustic environment.

Preliminary Model Analysis of Acoustic Noise Levels for Space Station

2014 ◽  
Vol 1016 ◽  
pp. 287-291
Author(s):  
Yao Qi Feng ◽  
Jiang Yang ◽  
Guo Song Feng ◽  
Yao Wu
Keyword(s):  
Acoustic Analysis ◽  
Acoustic Noise ◽  
Spectral Characteristics ◽  
Space Station ◽  
Low Frequency ◽  
Frequency Range ◽  
Analysis Model ◽  
Noise Levels ◽  
Noise Sources ◽  
Modeling And Analysis

This paper presents the modeling and analysis method of acoustic noise levels of whole audible frequency range for Chinese Space Station (CSS) module. UsingBoundaryElementModeling(BEM), the acoustic analysis model of low frequency range for CSS module was established. The analysis model of high frequency range was created by usingStatistical EnergyAnalysis(SEA) method. Based on the established models, the acoustic noise levels in all areas of CSS module were analyzed and the results for some typical areas are provided. Finally, the acoustic contribution of noise sources according to their spectral characteristics is analyzed and the implementation of noise control methods to reduce acoustic levels in CSS module is discussed.

scholarly journals The Impact of Noise Pollution on Workers’ Health in Selected Industries of Mirzapur Industrial Area, Tangail, Bangladesh

2017 ◽  
Vol 9 (2) ◽  
pp. 155-160 ◽  
Author(s):  
S Alam ◽  
ST Akter ◽  
MS Sheikh ◽  
I Bahar
Keyword(s):  
Noise Level ◽  
Heart Diseases ◽  
Noise Pollution ◽  
Industrial Area ◽  
Noise Levels ◽  
Textile Mill ◽  
Night Time ◽  
Noise Sources ◽  
Spinning Mill ◽  
The Impact

The unwanted and intolerable sound causes noise. The study was conducted through interviewing of workers and measuring of noise levels on six types of industries. The data were collected on April, May and June, 2013. The data of noise levels were measured at main gate, administration office and working place of the selected industries. The noise level at the working places during day time of the selected industries were 81.50 dB (textile mill), 104.20 dB (cotton mill), 90.50 dB (jute mill), 95.90 dB (spinning mill), 89.25 dB (knit and garments factory) and 83.50 dB (knitting factory), respectively. All the recorded noise level data in working places of the industries exceeded the DoE standard (75 dB at day time and 70 dB at night time) that caused noise pollution. The important contributors of noise pollution were machineries and overcrowding of the workers in the industry. Most of the common impacts of noise pollution were headache, heart diseases and hearing problem. To resolve the noise problem in industry it was suggested to eliminate the noise sources substituting noisy machineries and so on.J. Environ. Sci. & Natural Resources, 9(2): 155-160 2016

CALCULATION OF THE INTEGRAL NOISE LEVEL AT A FIELD POINT OF A FREE SUPERSONIC JET OF A ROCKET ENGINE

Akustika ◽  
2020 ◽  
Vol 36 (36) ◽  
pp. 22-24
Author(s):  
Anatoly Kochergin ◽  
Valeeva Ksenia
Keyword(s):  
Acoustic Field ◽  
Noise Level ◽  
Rocket Engine ◽  
Supersonic Jet ◽  
Noise Sources ◽  
Field Point

The paper considers an acoustic field created by a supersonic jet (CES) of a rocket engine freely flowing into flooded space. The acoustic field was presented in the form of a diagram of noise isobars, from which it can be seen that the acoustic field is formed by two effective noise sources: the nearest one, lying at a distance of 5-10 calibers from the nozzle cut and the far one, lying at a distance of 15-30 calibers from the nozzle cut.

scholarly journals Noise in Otolaryngology – Head and Neck Surgery operating rooms: a systematic review

2021 ◽  
Vol 50 (1) ◽  
Author(s):  
Gianluca Sampieri ◽  
Amirpouyan Namavarian ◽  
Marc Levin ◽  
Justine Philteos ◽  
Jong Wook Lee ◽  
...  
Keyword(s):  
Systematic Review ◽  
Head And Neck ◽  
Patient Outcomes ◽  
Noise Level ◽  
Neck Surgery ◽  
Operating Rooms ◽  
Head And Neck Surgery ◽  
Noise Levels ◽  
Surgical Performance ◽  
The Mean

Abstract Objective Noise in operating rooms (OR) can have negative effects on both patients and surgical care workers. Noise can also impact surgical performance, team communication, and patient outcomes. Such implications of noise have been studied in orthopedics, neurosurgery, and urology. High noise levels have also been demonstrated in Otolaryngology-Head and Neck Surgery (OHNS) procedures. Despite this, no previous study has amalgamated the data on noise across all OHNS ORs to determine how much noise is present during OHNS surgeries. This study aims to review all the literature on noise associated with OHNS ORs and procedures. Methods Ovid Medline, EMBASE Classic, Pubmed, SCOPUS and Cochrane databases were searched following PRISMA guidelines. Data was collected on noise measurement location and surgery type. Descriptive results and statistical analysis were completed using Stata. Results This search identified 2914 articles. Final inclusion consisted of 22 studies. The majority of articles analyzed noise level exposures during mastoid surgery (18/22, 82%). The maximum noise level across all OHNS ORs and OHNS cadaver studies were 95.5 a-weighted decibels (dBA) and 106.6 c-weighted decibels (dBC), respectively (P = 0.2068). The mean noise level across all studies was significantly higher in OHNS cadaver labs (96.9 dBA) compared to OHNS ORs (70.1 dBA) (P = 0.0038). When analyzed together, the mean noise levels were 84.9 dBA. Conclusions This systematic review demonstrates that noise exposure in OHNS surgery exceeds safety thresholds. Further research is needed to understand how noise may affect team communication, surgical performance and patient outcomes in OHNS ORs. Graphical abstract

Effective splicing localization based on noise level inconsistencies

2021 ◽  
pp. 1-11
Author(s):  
P. N. R. L. Chandra Sekhar Author ◽  
T. N. Shankar Author
Keyword(s):  
Digital Technology ◽  
Social Networking Sites ◽  
Noise Level ◽  
Research Work ◽  
Multimedia Content ◽  
Noise Levels ◽  
Multimedia Forensics ◽  
The Past ◽  
Photo Editing ◽  
State Of Art

In the era of digital technology, it becomes easy to share photographs and videos using smartphones and social networking sites to their loved ones. On the other hand, many photo editing tools evolved to make it effortless to alter multimedia content. It makes people accustomed to modifying their photographs or videos either for fun or extracting attention from others. This altering brings a questionable validity and integrity to the kind of multimedia content shared over the internet when used as evidence in Journalism and Court of Law. In multimedia forensics, intense research work is underway over the past two decades to bring trustworthiness to the multimedia content. This paper proposes an efficient way of identifying the manipulated region based on Noise Level inconsistencies of spliced mage. The spliced image segmented into irregular objects and extracts the noise features in both pixel and residual domains. The manipulated region is then exposed based on the cosine similarity of noise levels among pairs of individual objects. The experimental results reveal the effectiveness of the proposed method over other state-of-art methods.

scholarly journals Hot Box Investigations of a Ventilated Bioclimatic Wall for NZEB Building Façade

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1327
Author(s):  
Dwinanto Sukamto ◽  
Monica Siroux ◽  
Francois Gloriant
Keyword(s):  
Energy Efficiency ◽  
Flow Rate ◽  
Experimental Setup ◽  
Air Flow Rate ◽  
Space Thickness ◽  
Zero Energy ◽  
Interior Space ◽  
Air Space ◽  
Thermal Metrology

The building sector is the largest consumer of energy, but there are still major scientific challenges in this field. The façade, being the interface between the exterior and interior space, plays a key role in the energy efficiency of a building. In this context, this paper focuses on a ventilated bioclimatic wall for nearly zero-energy buildings (NZEB). The aim of this study is to investigate an experimental setup based on a hot box for the characterization of the thermal performances of the ventilated wall. A specific ventilated prototype and an original thermal metrology are developed. This paper presents the ventilated prototype, the experimental setup, and the experimental results on the thermal performances of the ventilated wall. The influence of the air space thickness and the air flow rate on the thermal performances of the ventilated wall is studied.

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