Evaluating worker noise exposure levels in the presence of complex noise

2021 ◽  
Vol 263 (5) ◽  
pp. 1733-1743
Author(s):  
William Murphy ◽  
Wei Qiu ◽  
Meibian Zhang

Recent research into the assessment of worker noise exposure has demonstrated that the combination of impulsive noise and continuous noise creates an additional risk of developing noise-induced hearing loss (NIHL). Zhang et al (2021) demonstrated that workers exposed to non-Gaussian noise accumulated NIHL at a faster rate over their careers than worker exposed to Gaussian noise. The kurtosis statistic of the sound pressure distribution provides a means to adjust the estimated risk of hearing loss between exposure groups exposed to different types of noise. This paper will review the results from our recent studies of kurtosis and exposure level. Some unanswered questions involve the selection of a suitable sample length to estimate kurtosis, the selection of a compensation factor to apply, and understanding the differences exhibited in short (less than 10 years) and long-term exposures and kurtosis.

Author(s):  
Feifan Chen ◽  
Zuwei Cao ◽  
Emad M. Grais ◽  
Fei Zhao

Abstract Purpose Noise-induced hearing loss (NIHL) is a global issue that impacts people’s life and health. The current review aims to clarify the contributions and limitations of applying machine learning (ML) to predict NIHL by analyzing the performance of different ML techniques and the procedure of model construction. Methods The authors searched PubMed, EMBASE and Scopus on November 26, 2020. Results Eight studies were recruited in the current review following defined inclusion and exclusion criteria. Sample size in the selected studies ranged between 150 and 10,567. The most popular models were artificial neural networks (n = 4), random forests (n = 3) and support vector machines (n = 3). Features mostly correlated with NIHL and used in the models were: age (n = 6), duration of noise exposure (n = 5) and noise exposure level (n = 4). Five included studies used either split-sample validation (n = 3) or ten-fold cross-validation (n = 2). Assessment of accuracy ranged in value from 75.3% to 99% with a low prediction error/root-mean-square error in 3 studies. Only 2 studies measured discrimination risk using the receiver operating characteristic (ROC) curve and/or the area under ROC curve. Conclusion In spite of high accuracy and low prediction error of machine learning models, some improvement can be expected from larger sample sizes, multiple algorithm use, completed reports of model construction and the sufficient evaluation of calibration and discrimination risk.


1995 ◽  
Vol 109 (4) ◽  
pp. 291-295 ◽  
Author(s):  
H. J. Cox ◽  
G. R. Ford

AbstractThe air conduction thresholds in the right and left ears, and the interaural asymmetry of thresholds at 0.5, 1, 2, 3, 4 and 6 kHz were measured in a group of 225 soldiers exposed to a variety of weapon noise who were referred for assessment because of a deterioration in hearing on routine testing. At 0.5 and I kHz the threshold levels rarely exceeded 25 dB and the interaural asymmetry was 10 dB or less in 90 per cent of cases. The degree of hearing loss and interaural asymmetry increased as the frequency increased, with the average loss being significantly greater in the left ear at 2, 3, 4 and 6 kHz.Recommendations are made for the selection of cases of asymmetrical hearing loss exposed to weapon noise which require further investigation to exclude a retrocochlear cause or to define spurious hearing threshold levels.


2021 ◽  
Author(s):  
Long Miao ◽  
Boshen Wang ◽  
Juan Zhang ◽  
Lihong Yin ◽  
Yuepu Pu

Abstract This study aimed to explore the association of several single nucleotide polymorphisms (SNPs) within the AKT2 gene and noise-induced hearing loss (NIHL) susceptibility and explore the potential mechanism underlying NIHL. Three SNPs (rs2304186, rs41275750 and rs76524493) were genotyped in a Chinese population which consists of 690 NIHL patients and 650 normal hearing controls. Bioinformatic analysis was conducted to predict the potential miRNA-binding site of SNPs. Cell transfection and dual-luciferase reporter assay were performed to investigate the potential molecular mechanism of SNPs involved in NIHL. The results revealed rs2304186 GT genotype (OR = 1.41; 95% CI = 1.09–1.83) and TT genotype (OR = 1.51; 95% CI = 1.08–2.10) imparted increased risk of NIHL, and the increased risk could also be found in a dominant model (OR = 1.44; 95% CI = 1.12–1.84). The stratification analysis showed that rs2304186 GT/TT conferred a higher risk for NIHL, especially in subgroups of male, age (35–45 and > 45 years), noise exposure time (> 16 years), and noise exposure level (≤ 85 and ≥ 92 dB), compared with GG genotype. In addition, the haplotype TCCTACT (rs2304186-rs41275750-rs76524493) was associated with NIHL risk (OR = 1.19; 95% CI = 1.02–1.40). Rs2304186 G allele combined with hsa-miR-625-5p mimics could significantly decrease the luciferase activity compared with T allele, indicating rs2304186 altered the binding affinity of hsa-miR-625-5p to SNP rs2304186 mutation region, thus directly targeting AKT2. In conclusion, our study provides evidence for the first time that SNP rs2304186 of AKT2 3′UTR affects NIHL susceptibility by affecting the binding affinity of has-miR-625-5p in an allele-specific manner and it may act as a potential biomarker of NIHL susceptibility.


2017 ◽  
Vol 38 (03) ◽  
pp. 223-224
Author(s):  
Mark Stephenson ◽  

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Zhihao Shi ◽  
Jiena Zhou ◽  
Yuwen Huang ◽  
Yong Hu ◽  
Lifang Zhou ◽  
...  

2019 ◽  
pp. 38-45
Author(s):  
Pensri Watchalayann ◽  
Laksana Laokiat

Noise exposure in the working environment is a major cause of hearing impairment for workers; an audiogram hearing threshold level above 20 dB is considered irregular. In this study, audiometric data were analyzed with the objective of assessing hearing loss among power plant workers based on their age, noise exposure level, years of working, and work characteristics. A cross-sectional study was conducted to assess hearing level data for 672 workers reserved by the Health Care Unit of the power plant. The most recent audiometric data presented during 2013-2015 were used in the statistical analysis at 5 % level of significance. It was found that the most dominant frequency with reference to age and work experience is the test frequency at 4,000 Hz. The most prominent suffering significant hearing loss for both ears is the age group of 50-60 years, consistent with more than 35 years of working. The most significant exposure level is noise level at 81-84 dBA for the left ear only. The work characteristics were found to be the most significant factor affecting hearing loss in both ears. The t-test reveals no significant difference in hearing loss in both ears at all test frequencies. Hearing loss is found to occur at 4,000 and 6,000 Hz; therefore, there is a necessity to implement noise control measures specifically for each work group. Although there is an educational and training program in the power plant, all workers should still be educated continuously on how to use hearing protection equipment correctly to enhance awareness of the hazards of noise to hearing. Periodic audiometry should be performed to early detect noise-induced hearing loss specifically the notch occurring at 4,000 and 6,000 Hz, together with engineering control in order to reduce unwanted sound.


2021 ◽  
Vol 104 (3) ◽  
pp. 349-358

Objective: To investigate hearing protection devices (HPDs) use and its relationship with hearing loss among steel industry workers in Thailand. Materials and Methods: The present cross-sectional study included 93 eligible participants who are working in the designated high-noise-level zones, which is 85 or more A-weighted decibels [dB(A)] for eight hours time-weighted average, of the two factories. Self-report forms were used to obtain HPDs use by industry workers and noise exposure level was measured with Spark® (Model 706) noise dosimeter. Audiometric screening for hearing loss was performed at a regional hospital by the qualified technician. The hearing loss in each ear was defined if the average threshold level was found to have exceeded 25 dB(A) at high frequencies of 4 and 6 kHz. Results: The findings showed that 45.2% of workers used earplug, 16.1% used earmuff, and 38.7% used both, and most workers (55.8%) wear HDPs regularly, for six of seven days per week. Fifty seven percent of workers wear HDPs for more than 60% time of an 8-hour work shift. Most workers (75.2%) have hearing loss. Conclusion: The authors’ result revealed that almost half of workers used hearing protection devices and most workers use HPDs during the 8-hour work time. Abnormal hearing ability were found among workers. The education program such as the hazards of noise on potential auditory loss, a noise education training program and full use of HPDs are encouraged to prevent effect of noise on workers. Keywords: Hearing protection devices, Noise induced hearing loss, Steel industry


2017 ◽  
Vol 38 (03) ◽  
pp. 225-262 ◽  
Author(s):  
Alice Suter

Noise levels are truly continuous in relatively few occupations, with some degree of intermittency the most common condition. The sound levels of intermittent noise are often referred to as non-Gaussian in that they are not normally distributed in the time domain. In some conditions, intermittent noise affects the ear differently from continuous noise, and it is this assumption that underlies the selection of the 5-dB exchange rate (ER). The scientific and professional communities have debated this assumption over recent decades. This monograph explores the effect of non-Gaussian noise on the auditory system. It begins by summarizing an earlier report by the same author concentrating on the subject of the ER. The conclusions of the earlier report supported the more conservative 3-dB ER with possible adjustments to the permissible exposure limit for certain working conditions. The current document has expanded on the earlier report in light of the relevant research accomplished in the intervening decades. Although some of the animal research has supported the mitigating effect of intermittency, a closer look at many of these studies reveals certain weaknesses, along with the fact that these noise exposures were not usually representative of the conditions under which people actually work. The more recent animal research on complex noise shows that intermittencies do not protect the cochlea and that many of the previous assumptions about the ameliorative effect of intermittencies are no longer valid, lending further support to the 3-dB ER. The neurologic effects of noise on hearing have gained increasing attention in recent years because of improvements in microscopy and immunostaining techniques. Animal experiments showing damage to auditory synapses from noise exposures previously considered harmless may signify the need for a more conservative approach to the assessment of noise-induced hearing loss and consequently the practice of hearing conservation programs.


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