Intensity–time tradeoff for constant hearing loss with high sound levels

1988 ◽  
Vol 83 (1) ◽  
pp. 203-211
Author(s):  
Gunnhild Oftedal ◽  
Mary Ellen Nivison ◽  
Zheng Jinze
Author(s):  
Greicikelly Gaburro Paneto ◽  
Cristina Engel de Alvarez ◽  
Paulo Henrique Trombetta Zannin

In contemporary cities, and usually without realizing it, the population has been exposed to high sound pressure levels, which besides causing discomfort, can lead to health problems. Considering that a large part of this noise comes from emission from motor vehicles, this research aims to evaluate the sound behavior in sound environments configured by voids in the urban fabric, in order to identify whether open spaces can act as attenuators of sound levels. To obtain the expected results, the methodology used was structured from a review of the state-of-the-art and computer simulations relating the variables that influence the formation of urban space and sound emission and propagation, taking as a case study an urban portion of the municipality of Vitória/ES. In parallel, questionnaires were applied to evaluate the user's perception of their exposure. The measurement results indicated that the sound pressure levels caused by traffic noise are above the limit tolerated limit by the NBR norm 10151:2000 for the daytime period. In turn, the results obtained from the population indicated that there is little perception of noise by the users of the spaces surveyed.


2021 ◽  
Vol 263 (4) ◽  
pp. 2590-2600
Author(s):  
Luiz Henrique Mesa Casa Pereira ◽  
Björn Knöfel ◽  
Jan Troge ◽  
Welf-Guntram Drossel ◽  
Marcel Klein ◽  
...  

Research on the relation between exposure to noise and cognitive performance inside industrial environments is not as broad as on office environments. For a better understanding of the specific industrial noise problems, participants performed arithmetic tests inside a hemi anechoic room while they were exposed to sounds of five typical industrial noise sources. The subjects also classified how annoying they perceived the noise signals. The effect of noise on the arithmetic test's performance was larger on accuracy than on velocity, which was verified using a Student t-test. Spectral-temporal characteristics - especially high frequency content and strong low frequency modulation - appear to relate better with lower performance on the test than high sound levels. Subjects that evaluated noise as more annoying performed worse in a final arithmetic test (under silence) after being exposed to the noises, indicating a possible cumulative effect of noise on performance. The findings provide a better insight in the cognitive behavior of people who are exposed to industrial noise. Hence, the study will proceed with the specific noise analysis of single industrial workplaces.


1993 ◽  
Vol 24 (3) ◽  
pp. 167-173 ◽  
Author(s):  
James E. Lankford ◽  
Denise M. West

The purpose of this study was to determine if noise in a high school woodworking class could contribute to the incidence of hearing loss. Students in the woodworking class served as the experimental group, and students in a technical drawing class were the control group. Four separate experiments were conducted. Experiment 1 consisted of measuring and comparing the sound levels in the woodworking and the technical drawing class environments. In Experiment 2, dosimetry samples of the students in both classrooms were collected. In Experiment 3, the temporary threshold shifts (TTSs) were determined for students in both groups by assessing hearing thresholds at the beginning and end of a single class period. The focus of Experiment 4 was to determine if a threshold shift had occurred in the hearing of the students in the woodworking class over a semester. Results of this study suggest that hazardous noise levels in the high school woodworking shop caused statistically significant TTS among the students. Relatively low noise doses were recorded, but no significant changes in hearing thresholds from the beginning to the end of the semester were noted. It was concluded that repeated noise exposure in a woodworking class may be a contributing factor to hearing loss among a student population and that a hearing conservation program should be instituted in these high school environments.


1996 ◽  
Vol 100 (4) ◽  
pp. 2626-2626
Author(s):  
Eric D. Young ◽  
Roger L. Miller ◽  
Jeff C. Wong

2011 ◽  
Vol 22 (02) ◽  
pp. 093-103 ◽  
Author(s):  
Gregory A. Flamme ◽  
Michael Stewart ◽  
Deanna Meinke ◽  
James Lankford ◽  
Per Rasmussen

Background: What is the risk of hearing loss for someone standing next to a shooter? Friends, spouses, children, and other shooters are often present during hunting and recreational shooting activities, and these bystanders seem likely to underestimate the hazard posed by noise from someone else's firearm. Hunters use hearing protection inconsistently, and there is little reason to expect higher use rates among bystanders. Acoustic characteristics and estimates of auditory risk from gunfire noise next to the shooter were assessed in this study. Research Design: This was a descriptive study of auditory risk at the position of a bystander near a recreational firearm shooter. Data Collection and Analysis: Recordings of impulses from 15 recreational firearms were obtained 1 m to the left of the shooter outdoors away from reflective surfaces. Recordings were made using a pressure-calibrated 1/4 inch measurement microphone and digitally sampled at 195 kHz (24 bit depth). The acoustic characteristics of these impulses were examined, and auditory risk estimates were obtained using three contemporary damage-risk criteria (DRCs) for unprotected listeners. Results: Instantaneous peak levels at the bystander location ranged between 149 and 167 dB SPL, and 8 hr equivalent continuous levels (LeqA8) ranged between 64 and 83 dB SPL. Poor agreement was obtained across the three DRCs, and the DRC that was most conservative varied with the firearm. The most conservative DRC for each firearm permitted no unprotected exposures to most rifle impulses and fewer than 10 exposures to impulses from most shotguns and the single handgun included in this study. More unprotected exposures were permitted for the guns with smaller cartridges and longer barrel length. Conclusions: None of the recreational firearms included in this study produced sound levels that would be considered safe for all unprotected listeners. The DRCs revealed that only a few of the small-caliber rifles and the smaller-gauge shotguns permitted more than a few shots for the average unprotected listener. This finding is important for professionals involved in hearing health care and the shooting sports because laypersons are likely to consider the bystander location to be inherently less risky because it is farther from the gun than the shooter.


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