Average Noise Exposure Levels Research Articles

Noise exposure assessment of workers inspecting construction machinery vehicles in the Republic of Korea.

Previous studies have investigated the health hazards caused by exposure to the noise of heavy equipment used at construction sites. Korea's Ministry of Land, Infrastructure, and Transport operates a registration system for construction machinery, and regular safety inspections are mandatory. Although workers inspecting construction machinery vehicles are exposed to unwanted noise, no noise exposure assessment has been made regarding these workers in Korea. The time-weighted average (TWA) daily average noise exposure level among construction machinery inspectors at 18 inspection centers was 75.3 dB(A). Among the inspection steps, the exhaust gas inspection step was found to exhibit the highest noise exposure level, up to 100 dB(A). In Korea, if the noise level of a workplace exceeds 85 dB(A) as a TWA, workers are required to undergo special medical examinations. This study found that special medical examinations were required for two of the 18 target inspection centers (approximately 115 workers) as the 8-hour TWA noise level exceeded 85 dB(A). Therefore, regular noise exposure assessment and special medical examinations for noise are required to prevent inspectors from developing hearing disorders due to noise exposure.

A Study on Assessment of Noise Levels in Various Construction Activities

Construction industry is one of the occupational hazardous workplaces. Most of the construction activities are involved with various risks, prone to occupational hazards. Noise is a physical hazard, resulting from simple headache to permanent hearing loss. Noise is not only confined to work involved but also involves surrounding activities like traffic, commercial activities of the construction sites. Each construction activity is associated with various tools, machinery, producing moderate to severe noise. Workers are exposed to repeated noise levels during worktime. The present study is to identify the machinery and tools producing high noise levels, calculating the average noise exposure levels, the dose levels pertaining to time weighted average levels during high work time. The survey, interview, observation based method adopted in collection and analysing the data .A collective number of noise levels were measured using Noise meter during the study . Ms excel sheet was used to analyse the dose levels and Time weighted average (TWA) . Construction activities exceeding the OSHA standards 85 dB, identified as noise hazard. Analysis concluded that concrete pouring activity produces a noise of 90 dB, exceeded the OSHA limit and carpentry activity just exceeds the limit. Based on survey 44.4% of the construction workers are responded as construction noise is not tolerable and 61.1% are not showing interest towards wearing of PPE.

Investigation of factors affecting hearing loss of open pit coal mine employees with categorical data analyses

One of the most important occupational diseases encountered in mining is the noise induced hearing loss (NIHL). In this study, analyses were carried out to examine the NIHL in the open pit lignite mine in Turkey. The NIHL was evaluated in accordance with the miners’ age, experience, occupation, exposure value (Lex), and maximum noise level (Lpeak). Noise levels exposed the employees were measured with noise dosimeters and a hearing test was applied to the employees by a special hearing center. To determine the parameters that could be effective in NIHL, all of the obtained data were evaluated by the logistic regression analysis (LRA) and hierarchical log-linear analysis (HLA) methods. It was determined that the NIHL probability of field staff is approximately 6 times higher than operators and drivers. According to the 21-29 age group, it was found that the probability of NIHL in the 57-65 and in the 48-56 age group was 11.4 and 4.41 times higher, respectively. Experience and maximum noise levels were found to be the most important parameters in hearing loss. Besides these, it was determined that the interactions of age×experience, occupation×maximum noise levels, and occupation×average noise exposure levels increased the likelihood of NIHL. A logistic regression model has been developed for the NIHL estimation of employees and hearing loss was found to be a problem mostly for those working in the field. It was determined that hearing loss increased with age and experience, and varied according to occupational groups.

Self Reported Hearing Impairments and Associated Risk Factors Among Metal and Woodwork Workers in Gondar Town, North West Ethiopia.

Background:The global prevalence of occupational noise-induced hearing loss ranges between 16% and 24%. The wood and metalwork industries have recently expanded in Ethiopia. This study aims to determine the level of noise exposure and the prevalence of self-reported hearing impairments and associated risk factors among metal and woodworkers in Gondar town Ethiopia.Material and Methods:An institutional-based cross-sectional study was conducted on 580 metal and woodwork workers from February10 to March 25/2020. The data were collected through an interviewer-led questioner and the noise level measurement. Multivariate Poisson regression models were used. P-values less than .05 and adjusted prevalence ratios with 95%CI were used to declare the presence and strength of an association respectively.Result:The mean (SD) average noise exposure level in the wood and metalworking industries was 96.9 ± 3.5 dBA and 96.2 ± 4 dBA, respectively. The overall prevalence of self-reported hearing impairment was 20.7% [95%CI: (17.4-24)]. In an adjusted Poisson regression, listening to music with earphones for more than 2 hours per day (PR = 2.95, 95%CI: 1.32, 6.21) and listening to music at maximum volume (PR = 2.24, 95%CI: 1.05, 4.79) were associated with hearing impairments.Conclusion:The majority of workers are exposed to noise levels that exceed OSHA’s permissible exposure limit value. A hearing conservation program should be implemented to reduce noise exposure levels in the wood and metal work industries. Workers should be aware of the duration and volume of recreational noise exposure.

Noise Exposure and Noise Induced Hearing Loss Among the Traffic Police in Dhaka Metropolitan City

Background: Occupational noise is considered as a global problem with social and physiological impacts, causing noise-induced hearing loss (NIHL). High levels of occupational noise is a problem in all regions of the world. Road traffic produces high noise levels that can cause damage to the traffic police hearing. Hence, occupational hearing loss is a well-known outcome of noise exposure at work. Objectives: The study aimed to measure the noise exposure level at different traffic points and determine the occurrence rate and severity of hearing loss among the traffic police of Dhaka Metropolitan City. Methods: This cross-sectional study was conducted during 2017-2019 in 28 selected traffic points of Dhaka Metropolitan City under four traffic zone (East, West, North, and South) and among 100 traffic police who were working there and met the inclusion and exclusion criteria. Noise exposure level was measured from all selected traffic points with a digital sound level meter. Data were collected by face to face interview with a pretested semi-structured questionnaire followed by an otoscopic examination, tuning fork tests, and a baseline audiogram. To see the association, Chi-square tests or Pearson’s correlation coefficient (r) tests were performed. Results: This study revealed that the average noise exposure level at East, West, North, and South zones are respectively 125.6 dB, 112.9 dB, 121.3 dB, and 119.4 dB. At every point, the noise exposure level was more than the acceptable limit set by the Occupational Safety and Health Administration (OSHA). In the audiometry report of 100 traffic police, 64% had sensorineural hearing loss. Of them 85% had mild, 9% had moderate and 6% with severe hearing loss. Notch in 4 kHz in an audiogram was present in the right ear of 46% of respondents and left ear of 52% respondents. It was observed that hearing loss was significantly associated with increasing age and job duration. Conclusion: Traffic police of Dhaka Metropolitan City is in constant risk of noise induced hearing loss as the ambient noise of this city is very high. Regular assessment and hearing screening is recommended for all the traffic police who are exposed to noise. Bangladesh Med Res Counc Bull 2020; 46(3): 219-227

Assessment of Motorcycle Noise Exposure Levels (LAeq, dBA) at Various Noise Standards and Speeds

Motorcyclists (n=26) average noise exposure levels (LAeq) were found substantially different for OSHA-HC (85 dBA), OSHA-PEL (78 dBA) and ACGIH/NIOSH (87 dBA) noise standards. A significant difference in LAeq, (p=.027) and engine capacity usage (p=.045) was found amongst gender. However, no observable association was found between the LAeq and motorcycle engine capacity (p= .462) and completion of a ride (p= .695). Thus, female riders were inclined to use lower motorcycle capacities, rode at lower speeds which resulted in lower noise exposure levels, in concurrence with longer ride durations. Overall, motorcyclists’ noise exposure level functions with the increasing speed (80km/h: 88 dBA). Keywords: Motorcycle noise; Dosimeter; Speed; Noise standards eISSN: 2398-4287© 2020. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v5i15.2455.

Association between Exposure to Noise and Sleep and Mental Health Outcomes in a Nationally-Representative Sample of U.S. Adolescents

Background: In 1974, the U.S. Environmental Protection Agency (U.S. EPA) identified an equivalent 24-hour continuous average noise exposure level (LAeq, 24h) of < 55 A-weighted decibels to protect public health with an adequate margin of safety. To date, however, limited U.S.-based research has evaluated the relationship between noise pollution and health. We help fill this gap using data from a nationally-representative sample of U.S. adolescents.Methods: We used a cross-sectional geospatial sound model to estimate noise exposure at the block group level. We dichotomized noise as high (LAeq, 24h ≥ 55 dB) versus low (LAeq, 24h <55 dB). The National Comorbidity Survey Adolescent Supplement, conducted between 2001-2004 and including several self-reported sleep outcomes and DSM-IV disorder diagnoses, provided our study population. We evaluated the association between noise and sleep and mental health using doubly-robust targeted minimum loss-based estimation and propensity score matching to account for potential confounders, including air pollution.Results: The study included 4,508 urban-dwelling adolescents aged 13-18. Controlling for numerous adolescent, household, and environmental covariates, living in a high- versus low-noise census block-group was associated with later bedtimes on both weeknights and weekend nights (risk difference [RD]: 0.41 hours, 95% CI: -0.01, 0.83, and RD: 0.61 hours, 95% CI: 0.38, 0.84, respectively). We found no association with total number of hours slept. Further, we found that living in a high- versus low-noise census block-group was associated with 69% increased odds of an anxiety or depressive disorder (odds ratio [OR]: 1.69, 95% CI: 1.13, 2.25) and 79% increased odds of substance use disorder (OR: 1.79, 95% CI: 0.91, 2.66); we found no similar associations with behavioral disorders.Conclusion: We found evidence that noise exceeding the U.S. EPA threshold may hold adverse sleep and mental health consequences for U.S. adolescents.

At-ear noise levels under the helmet: a field study on noise exposure of young motorcyclists

At-ear noise exposure assessments of motorcyclists, with the function of speed, would be unsafe as on-road data acquisition has certain constraints including the operations and portability of appropriate instrument. Currently, there are no standardized protocols and methods for measuring the noise under motorcycle helmets. Furthermore, standard permissible noise emission levels for commuter motorcyclists are also not defined. Therefore, this study was aimed to investigate the motorcycle noise exposure assessments in realistic environment among young riders. A personal dosimeter was utilized to calculate the daily noise exposure level (L Aeq , 8h) under three different standards including: OSHA-HC (Occupational Safety and Health Administration, Hearing Conservation), OSHA-PEL (Permissible Emission Level) and ACGIH/NIOSH (American Conference of Governmental Industrial Hygienists/ National Institute of Occupational Safety and Health). The study design consisted of noise assessment of riders (age range:19 to 25 years) at-ear under the open-face helmet in-realistic situation (main road to the motorway) motorcycling in dry weather conditions. Personal dosimeter results ( n =52) revealed the average noise exposure level of 93.64 dBA, 92.51 dBA, 95.29 dBA for OSHA-HC, OSHA-PEL and ACGIH/NIOSH respectively. The mean Time-Weighted Average (TWA) was 76.82 dBA, 75.69 dBA, 85.16 dBA for OSHAHC, OSHA-PEL and ACGIH/NIOSH respectively. Under the ACGIH and NIOSH standard, the TWA for motorcyclists is at hazardous limits, which requires further investigations associated with health effects on riders. Standardized methods and configurations should be set for assessing noise exposure related to the motorcycling. Keywords: Motorcycle noise, Wind noise, Dosimeter, OSHA, ACGIH

Diurnal variability of transportation noise exposure and cardiovascular mortality: A nationwide cohort study from Switzerland.

Most epidemiological noise studies consider 24 h average noise exposure levels. Our aim was to exploratively analyze the impact of noise exposure at different time windows during day and night on cardiovascular mortality. We generated Switzerland-wide exposure models for road traffic, railway and aircraft noise for different time windows for the year 2001. Combined noise source equivalent continuous sound levels (Leq) for different time windows at the most exposed façade were assigned to each of the 4.41 million Swiss National Cohort adult participants. Follow-up period was from 2000 to 2008. Hazard ratios (HR) of noise effects on various cardiovascular primary causes of death were computed by Cox regression models adjusted for potential confounders and NO2 levels. For most cardiovascular causes of death we obtained indications for a diurnal pattern. For ischemic heart disease the highest HR was observed for the core night hours from 01 h to 05 h (HR per standard deviation of Leq: 1.025, 95% CI: 1.016-1.034) and lower HR for the daytime 07 h to 19 h (1.018 [1.009-1.028]). Heart failure and daytime Leq yielded the highest HR (1.047 [1.027-1.068]). For acute cardiovascular diseases, nocturnal intermittent noise exposure tended to be more relevant than daytime exposure, whereas it was the opposite for chronic conditions such as heart failure most strongly associated with continuous daytime noise. This suggests that for acute diseases sleep is an important mediator for health consequences of transportation noise.

Occupational noise exposure and risk of hypertension in an industrial workforce.

Community noise exposure has been shown to increase the risk of hypertension; however, the relationship between occupational noise exposure and hypertension is less clear. Using an inception cohort of workers in a specialty metals manufacturing company, we retrospectively assessed occupational noise exposure, hearing acuity, and incident hypertension diagnoses using administrative datasets. Time-weighted average noise exposure levels were assigned to employees based on their job histories. Cox proportional hazards models were performed to determine the association of noise exposure with risk of incident hypertension. The adjusted hazard ratio (HR) of incident hypertension did not significantly differ between groups by cumulative continuous or categorized noise exposure metric. We found no increased risk of incident hypertension with exposure to occupational noise among workers. Further assessment examining workers' use of hearing protection devices is warranted.

Assessment of noise exposure and associated health risk in school environment

Noise exposure has become one of the most important factors in determining the quality of life in indoor environments. This paper assesses and analyzes noise exposure levels at school and preschool classrooms with different indoor environments. The sound level [A-weighting equivalent steady sound level L Aeq (dBA)] was measured using a CEL-63× digital sound level meter. The noise level measurements were performed inside two preschools at three classrooms (an activity room, classroom KG1 and classroom KG2) and three schools at different classrooms, starting from grade 1 to grade 12. The logarithmic average noise levels (L Aeq avg) and the 8-h average noise exposure level (L EX, 8-h) were estimated for each classroom. Furthermore, health risk issues associated with the exposure to high noise levels were investigated using a questionnaire and an interview with more than 250 teachers at the preschools and the schools. Then, the results were analyzed using different statistical tools and were compared with the World Health Organization, Occupational Health and Safety and National Institute for Occupational Safety and Health standards. Also, the results were compared with those from different countries worldwide. The study results show that the 8-h average noise exposure level exceeded the allowable limits in some schools, which indicates that students and teachers can face a serious health effects from noise exposure. The comparisons show that the values of noise levels in Kuwait are higher than those in different countries. The maximum value of noise levels was found in secondary schools. The health problems found during the survey are potentially associated with issues related to hearing, voice, headache and the physiological function of teachers.

Comparison of two dose-response relationship of noise exposure evaluation results with high frequency hearing loss.

Background:Complex noise and its relation to hearing loss are difficult to measure and evaluate. In complex noise measurement, individual exposure results may not accurately represent lifetime noise exposure. Thus, the mean LAeq,8 h values of individuals in the same workgroup were also used to represent LAeq,8 h in our study. Our study aimed to explore whether the mean exposure levels of workers in the same workgroup represented real noise exposure better than individual exposure levels did.Methods:A cross-sectional study was conducted to establish a model for cumulative noise exposure (CNE) and hearing loss in 205 occupational noise-exposed workers who were recruited from two large automobile manufacturers in China. We used a personal noise dosimeter and a questionnaire to determine the workers’ occupational noise exposure levels and exposure times, respectively. A qualified audiologist used standardized audiometric procedures to assess hearing acuity after at least 16 h of noise avoidance.Results:We observed that 88.3% of workers were exposed to more than 85 dB(A) of occupational noise (mean: 89.3 ± 4.2 dB(A)). The personal CNE (CNEp) and workgroup CNE (CNEg) were 100.5 ± 4.7 dB(A) and 100.5 ± 2.9 dB(A), respectively. In the binary logistic regression analysis, we established a regression model with high-frequency hearing loss as the dependent variable and CNE as the independent variable. The Wald value was 5.014 with CNEp as the independent variable and 8.653 with CNEg as the independent variable. Furthermore, we found that the figure for CNEg was more similar to the stationary noise reference than CNEp was. The CNEg model was better than the CNEp model. In this circumstance, we can measure some subjects instead of the whole workgroup and save manpower.Conclusions:In a complex noise environment, the measurements of average noise exposure level of the workgroup can improve the accuracy and save manpower.

터널공사현장 근로자의 소음노출 특성 평가

The noise levels of workers in tunnel sites are likely to be high because tunneling work places are confined space. However, research on the noise exposure levels of tunneling workers have not been performed intensively due to restricted accessibility to tunnel construction sites. The aim of this study is to evaluate the noise exposure levels for workers engaged in tunneling work sites. Noise dosimeters were used for monitoring workers` noise exposure level in 5 tunneling work sites in accordance with the Notification of the Ministry of Labor. Among 5 tunneling work sites, 4 of them used NATM tunneling method and 1 work site used shield TBM tunneling method. The average noise exposure levels of NATM tunneling workers was 81.1 dB(A) and 15.4 % of the workers` noise level were exposed more than 90 dB(A) which is the exposure limit value. In Shield TBM tunneling method, 4.3 % of the workers were exposed more than 90 dB(A) of noise level, the average noise exposure levels of TBM tunneling workers was 84.1 dB(A).

Assessment of noise level in sundry processing and manufacturing industries in Ilorin metropolis, Nigeria

In this work, noise level in five selected processing and manufacturing industries in Ilorin are evaluated and compared. Emphasis is given to noise emitted by individual industrial machinery from the selected industries. Event L(Aeq) and L(N) cycles were studied to identify the noisy machines and to generate baseline data. Findings show that hammer mill machine from mineral-bearing rock-crushing mills produced the highest average noise [98.4 dB(A)], an electric generator 1 [95.6 dB(A)] from the soft drink bottling industry, an electric generator [97.7 dB(A)] from the beer brewing and bottling industry, a vacuum pump [93.1 dB(A)] from the tobacco making industry, and an electric generator 2 [94.1 dB(A)] from the mattress-making industry. The highest and lowest average noise exposure levels are recorded in mineral-bearing rock-crushing mills [93.16 dB(A)] and the mattress making industry [84.69 dB(A)], respectively. The study shows that, at 95% confidence level, there is significant difference (P < 0.05) in noise levels in the industries surveyed. The percentages of machines that emit noise above Federal Environmental Protection Agency and Occupational Safety and Health Administration recommendations [90 dB(A)] are from the soft drink bottling industry (83.3%), the beer brewing and bottling industry (42.9%), the tobacco making industry (71.4%), the mattress making industry (11.1%), and minerals crushing mills (87.5%). In the past 20 years, the noise levels in the soft drink bottling industry were reduced by 0.58 dB(A), and those of the beer brewing and bottling industry were reduced by 9.66 dB(A). However, that of the mattress making industry increased by 2.69 dB(A). On average, the noise level in these industries has been reduced by 2.52 dB(A). The results of this study show that the noise control measures put in place have significant impacts on the noise exposure level in the industries surveyed.

An Overview of Industrial Employees' Exposure to Noise in Sundry Processing and Manufacturing Industries in Ilorin Metropolis, Nigeria

In this work, an overview of industrial employees' noise exposure level in five selected processing and manufacturing industries in Ilorin are evaluated and compared. Emphasis is given to noise emitted by individual industrial machinery from the selected industries. Event L(Aeq) and LN cycle were studied to identify the noisy machines and to generate baseline data. Findings show that, hammer mill machine from mineral crushing mills produced the highest average noise (98.4 dB(A), electric generator1 (95.6 dB(A) from soft drink bottling industry, electric generator (97.7 dB(A)) from beer brewing and bottling industry, vacuum pump (93.1 dB(A)) from tobacco making industry and electric generator 2 (94.1 dB(A) from mattress making industry. The highest and lowest average noise exposure levels are recorded in mineral crushing mills (93.16 dB(A)) and mattress making industry (84.69 dB(A)) respectively. The study shows that at 95% confidence level, there is significant difference (p<0.05) in noise levels in the industries surveyed. The percentages of machines emit noise above FEPA and OSHA recommendation (90 dB(A)) are: soft drink bottling industry (83.3%), beer brewing and bottling industry (42.9%), tobacco making industry (71.4%), mattress making industry (11.1%) and minerals crushing mills (87.5%). In the past 20 years, the noise levels in soft drink bottling industry reduced by 0.58 dB(A) and that of beer brewing and bottling industry reduced by 9.66 dB(A). But that of mattress making industry increased by 2.69 dB(A). On the average, the noise level in these industries has reduced by 2.52 dB(A). The results of this study show that the noise control measures put in place have significant impact on the noise exposure level in the industries surveyed.

Assessment of personal noise exposure of overhead-traveling crane drivers in steel-rolling mills

Noise is widespread occupational hazard in iron and steel industry. Overhead-traveling cranes are widely used in this industry, but few studies characterized the overhead-traveling crane drivers' noise exposure level so far. In this study, we assessed and characterized personal noise exposure levels of overhead-traveling crane drivers in two steel-rolling mills. One hundred and twenty-four overhead-traveling crane drivers, 76 in the cold steel-rolling mill and 48 in the hot steel-rolling mill, were enrolled in the study. Personal noise dosimeters (AIHUA Instruments Model AWA5610e, Hangzhou, China) were used to collect full-shift noise exposure data from all the participants. Crane drivers carried dosimeters with microphones placed near their collars during the work shifts. Work logs had been taken by the drivers simultaneously. Personal noise exposure data were divided into segments based on lines in which they worked. All statistical analyses were done using SPSS 13.0. The average personal noise exposure (L(Aeq.8h)) of overhead-traveling crane drivers in the hot steel-rolling mills ((85.03 +/- 2.25) dB (A)) was higher than that in the cold one ((83.05 +/- 2.93) dB (A), P < 0.001). There were 17 overhead traveling cranes in the hot steel-rolling mill and 24 cranes in the cold one, of which carrying capacities varied from 15 tons to 100 tons. The average noise exposure level based on different lines in the hot and cold steel-rolling mills were (85.2 +/- 2.61) dB (A) and (83.3 +/- 3.10) dB (A) respectively (P = 0.001), which were similar to the average personal noise exposure in both mills. The noise exposure levels were different among different lines (P = 0.021). Noise exposure levels, depending upon background noise levels and the noise levels on the ground, are inconstant. As the noise exposure levels are above the 85 dB (A) criteria, these drivers should be involved in the Hearing Conservation Program to protect their hearing.

Study on personal noise exposure in China

A survey of personal noise exposure has been in progress in Beijing, China, since 1989 and the data on 221 subjects have been collected so far. In the survey, personal noise exposure measurements over one day and night were carried out. At the same time, personal major activity schedules, questionnaires concerning personal living and working environments, and reactions to environmental noise were investigated. On the basis of these data, personal noise exposure for residents of Beijing has been studied. The main factors that affect the noise exposure of a person are discovered. The L eq24 values of 86% of subjects are higher than 70 dB and the average noise exposure level L eq24 is 75.6 dB for residents of Beijing. The classification of the personal noise exposure patterns depends on age, sex and, especially, occupation. The personal noise exposure pattern varies with time of day, and it depends mainly on the noise levels of personal activities in daily life. The greatest exposure to noise is during work activities. Furthermore, personal noise exposure patterns have been compared with the environmental noise level measured in Beijing in 1986.

Sampling strategy for noise dosimetry measurements

The U.S. Army has adopted most of the new ACGIH TLVs as criteria in its hearing conservation program. Most significant to the Army program was the change from a non-time-weighted inclusion criterion to the 8-h time-weighted average noise exposure level (TWA). The TWA must now be identified for all Army civilian personnel subjected to hazardous noise exposure and for soldiers working in noise-hazardous industrial operations. This can be accomplished without making noise dosimetry measurements on every single individual suspected of being exposed to hazardous noise. The U.S. Army Environmental Hygiene Agency Technical Guide 181 on noise dosimetry and risk assessment was developed as a guide for evaluating types of noise exposure patterns and includes sampling strategies for dosimetry measurement of TWAs. The statistical basis of the sampling approach will be discussed in some detail. Other changes in the Army hearing conservation program resulting from the adoption of the TLVs will be outlined.

The need for and benefits of audiometric data base analysis procedures

Some noise‐exposed employees are losing their hearing despite the implementation of hearing conservation programs (HCPs). Employers do not know how to evaluate HCP effectiveness, and audiograms arc often filed away after testing. Employers lack guidance from professionals. They also lack regulatory guidance, since OSHA's hearing conservation amendment has no provisions for evaluating HCP effectiveness. Compounding the confusion is OSHA's policy not to issue citations for average noise exposure levels between 90 and 100 dBA when “the results of audiometric testing indicate that any existing controls and hearing protectors are adequately protecting employees.” OSHA gives no guidance, however, as to the assessment of adequate protection. Audiometric data base analysis (ADBA) procedures can yield valuable information on HCP effectiveness. They encourage accountability by management, consultants, employees, and compliance officers. They provide feedback to supervisors, motivating them to promote and enforce good HCPs in their departments. They provide feedback to employees, which can change or reinforce their behavior, as appropriate, toward hearing protector use. ADBA procedures provide the means for identifying and the stimulus for improving poor HCPs, and they provide a source of satisfaction and potential reward for effective ones.