METHOD AND APPARATUS FOR CONTINUOUS NOISE EXPOSURE MONITORING

2013 ◽  
Vol 133 (3) ◽  
pp. 1847
Author(s):  
Kevin Michael
2021 ◽  
Vol 263 (4) ◽  
pp. 2740-2754
Author(s):  
Jose Limardo ◽  
Christopher S. Allen ◽  
Richard W. Danielson ◽  
Andrew J. Boone

Environmental noise in space vehicles, caused by onboard equipment and crew activities, has generated concerns for crew health and safety since early U.S. space missions. The International Space Station (ISS) provides a unique environment where acoustic conditions can be monitored while crewmembers from the U.S. and their international partners work and live for as long as 6 to 12 consecutive months. This review of acoustic dosimetry data collected to date reveals that the noise exposure limits of NASA's stringent noise constraint flight rule have been exceeded in 41% of these dosimetry measurements since ISS Increment 17 (2008), with undefined impacts to crew. These measurements do not take into account the effects of hearing protection devices worn by the crew. The purpose of this paper is to provide an update on ISS noise exposure monitoring approaches and hearing conservation strategies that include acoustic dosimetry data collected since the ISS Increment 55 mission (April 2018). Future directions and recommendations for the ISS noise exposure monitoring program will also be presented, including research initiatives aimed at better defining the impact of ISS noise on crew health and performance.


1977 ◽  
Vol 86 (6) ◽  
pp. 821-826 ◽  
Author(s):  
William Melnick

Nine men were exposed to 24 hours of continuous noise in a sound field. The noise was an octave band centered at 4 kHz at levels 80 and 85 dB. Hearing thresholds were measured monaurally at 11 test frequencies ranging from 250 to 10000 Hz before, during, and after exposure. Temporary threshold shift (TTS) reached maximum levels at 8 to 12 hours of exposure. Maximum TTS occurred at 4 and 6 kHz. Mean asymptomtic threshold shifts (ATS) resulting from the 80 dB exposure level were 9.3 dB for 4 kHz and 7.2 dB for 6 kHz. For the 85 dB noise level, these threshold shifts were 17.8 dB and 14.6 dB respectively. The increase in ATS with increase of noise level for these two frequencies could be fitted with a straight line having a slope of 1.6.


1983 ◽  
Vol 92 (6) ◽  
pp. 623-628 ◽  
Author(s):  
Joseph Sataloff ◽  
Robert T. Sataloff ◽  
Raymond A. Yerg ◽  
Hyman Menduke ◽  
Robert P. Gore

Most studies of the effects of noise upon hearing have dealt with continuous noise exposure. Previous reports on intermittent exposure to noise concluded that it causes less damage to hearing than does continuous exposure to noise of the same intensity. In this investigation, 12,000 workers were screened to find 295 subjects who met the strict criteria of the study. Most of the subjects were exposed to jackhammer noise at peak levels of 118 dBA. Intermittent exposure to intense noise results in very severe loss in high frequencies but relatively little or no hearing loss in the lower frequencies even after many years of exposure. This differs substantially from the effects of continuous exposure to noise of the same intensity. It remains to be determined whether this pattern of hearing results from intermittent exposure to all sorts of noise or only from the kinds of sources investigated in this study.


Noise exposure monitoring is essential to assess noise exposure circumstances and provide a noise control plan to minimize noise exposure problems in the workplace. In Malaysia, occupational noise exposure problems have been increasing, especially in the construction industry. Hence, this study aims to investigate the noise exposure problem in a construction casting yard in Malaysia. The objectives of the study were to measure the current occupational noise exposure problem and to propose a noise control action. Field measurement was carried out at a segmented box girder casting yard under the Mass Rapid Transit (MRT) construction project in Selangor, Malaysia. A total of six case studies from four different construction trades had been conducted. This study plotted noise maps and measured personal noise exposure levels for the three construction trades. The results showed that the equivalent sound level exceeded the action level of 85 dBA for these trades. Besides, the bar cutting trade with an 8-hour time-weighted average of 92.3 dBA exceeded the permissible exposure limit of 90 dBA. The noise reduction rating of the hearing protection device was evaluated, and appropriate noise control action was proposed. The proposed noise reduction rating was 32 dBA, so it is expected to reduce the time-weighted average sound level below 80 dBA for this workplace. In conclusion, the results could disseminate to construction workers to raise their risk awareness regarding the noise exposure issue in the workplace. The noise mapping information could also be used for the design of the engineering control to reduce the noise exposure level in the construction workplace.


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