Use of historical data and a novel metric in the evaluation of the effectiveness of hearing conservation program components. Efficacy of enforcement in an industrial hearing conservation program. Hearing conservation programs (HCPs): the effectiveness of one company's HCP in a 12-hr work shift environment. Effectiveness of a tailored intervention to increase factory workers' use of hearing protection. Effectiveness of an intervention to increase construction workers' use of hearing protection. The effectiveness of hearing protective devices. Use of comparison populations for evaluating the effectiveness of hearing loss prevention programs. A hearing conservation program for Wisconsin youth working in agriculture. Efficacy of a computer-based hearing test and tailored hearing protection intervention. A controlled investigation of in-field attenuation performance of selected insert, earmuff, and canal cap hearing protectors. Effect of daily noise exposure monitoring on annual rates of hearing loss in industrial workers. An evaluation of the effectiveness of two different insert types of ear protection in preventing TTS in an industrial environment. Hearing conservation program for agricultural students: short-term outcomes from a cluster-randomized trial with planned long-term follow-up. The impact of hearing conservation programs on incidence of noise-induced hearing loss in Canadian workers. A multi-component intervention to promote hearing protector use among construction workers. Effectiveness of computer-based tailoring versus targeting to promote use of hearing protection. Effects of booster interventions on factory workers' use of hearing protection. Early indicators of hearing conservation program performance. Changes over time in audiometric thresholds in a group of automobile stamping and assembly workers with a hearing conservation program. Does a 3-day workshop for family medicine trainees improve preventive care? A randomized control trial. An epidemiologic method for assessing the effectiveness of hearing conservation programs using audiometric data. Noise exposure and hearing conservation in U.S. coal mines--a surveillance report. The application of positive practice overcorrection to the use of hearing protection.
To evaluate the effectiveness of hearing conservation programs (HCP) and their specific components in reducing noise-induced hearing loss (NIHL).
                This retrospective cohort study was conducted at one food-processing plant and two automotive plants. Audiometric and work-history databases were combined with historical noise monitoring data to develop a time-dependent exposure matrix for each plant. Historical changes in production and HCP implementation were collected from company records, employee interviews and focus groups. These data were used to develop time-dependent quality assessments for various HCP components. 5478 male (30,427 observations) and 1005 female (5816 observations) subjects were included in the analysis.
                Analyses were conducted separately for males and females. Females tended to have less NIHL at given exposure levels than males. Duration of noise exposure stratified by intensity (dBA) was a better predictor of NIHL than the standard equivalent continuous noise level (L(eq)) based upon a 3-dBA exchange. Within this cohort, efficient dBA strata for males were <95 versus ≥ 95, and for females <90 versus ≥ 90. The reported enforced use of hearing protection devices (HPDs) significantly reduced NIHL. The data did not have sufficient within-plant variation to determine the effectiveness of noise monitoring or worker training. An association between increased audiometric testing and NIHL was believed to be an artifact of increased participation in screening.
                Historical audiometric data combined with noise monitoring data can be used to better understand the effectiveness of HCPs. Regular collection and maintenance of quality data should be encouraged and used to monitor the effectiveness of these interventions. Relative efficacy of various levels of enforcement in the use of personal hearing protective devices was investigated among employees of a large industrial plant. The main variable was that each of four groups of employees worked during a different period of enforcement policy on the use of personal hearing protection. Analysis of variance of mean hearing levels using three different audiometric grading schemes with different levels of sensitivity, namely, the 0.5, 1, 2 kHz Hearing Level Index, the 1, 2, 3 kHz Hearing Level Index, and the 4000 Hz single puretone test indicate that the enforcement policy did have a dramatic effect on the efficacy of the hearing conservation program and should give similar results in other industrial settings. When and where the use of personal hearing protection was left to the employee it was found that hearing loss among the noise-exposed was very much in excess of that among a non-noise-exposed group. Mandatory use of personal protective devices was found to be much more effective in conserving hearing that the voluntary approach. Mandatory use of earmuffs exclusively proved to be less effective than mandatory use of personal hearing protection when the employee was given a choice of earmuffs or earplugs. Enactment of the Occupational Safety and Health Act did not result in greater hearing conservation over the existing company mandatory hearing conservation program which is quite effective. An existing hearing conservation program (HCP), originally designed when an 8-hr work shift schedule was in effect, was evaluated at a plant site where a 12-hr work shift schedule is now utilized. The study included the following phases: a noise analysis of the work environment, HCP evaluation through the use of audiometric data base analysis (ADBA), applying ADBA procedures and a comparison of the shift in hearing threshold levels (HTLs) for the 8-hr and 12-hr work shifts, and an evaluation of the hearing protection devices (HPDs) being used at the facility over the 12-hr work shift by measuring temporary threshold shift (TTS). The mean measured employee time-weighted average (TWA) in the process area where the TTS study was conducted was 92 dBA. It was found that the existing HCP is at best marginal. The most likely causes of this less-than-desirable rating are inadequate audiometric testing procedures and inadequate HPD utilization. Furthermore, it was concluded that, at this time, the introduction of the 12-hr work shift has had no impact on the level of effectiveness of the HCP. In evaluating the three HPDs in use at the facility (3-M foam earplug, E-A-R foam earplug, and Bilsom Soft earplug), it was found that they all offered effective protection from noise at all audiometric test frequencies (0.5 to 6 kHz) except 0.5 kHz. All three HPDs exhibited TTS at 0.5 kHz with the TTS measured significant at the p less than 0.05 level for the E-A-R and 3-M wearer groups. In the United States it is estimated that more than 30 million workers are exposed to harmful levels of noise on the job. When engineering or administrative controls cannot be used to reduce noise, workers should always use hearing protection devices (HPDs) when exposed to loud noise to prevent noise-induced hearing loss (NIHL). Previous research has shown that workers do not always use HPDs when required; therefore, it is essential that workers assume personal responsibility for preventing NIHL by increasing their use of HPDs.
                This study tested the effectiveness of an individually tailored multimedia intervention to increase use of HPDs by factory workers.
                A randomized controlled design was used to compare the effects of a tailored intervention (n= 446) with two other interventions (a nontailored predictor-based intervention (n= 447) and a control intervention (n= 432)) on workers' self-reported use of HPDs 6 to 18 months following the intervention.
                Only those workers receiving the tailored intervention significantly increased their use of HPDs from pretest to posttest. However, this increase significantly differed from the nontailored group but not from the control group.
                Individually-tailored interventions offer promise for changing behavior. In light of the similarity between the results for the tailored intervention and the control intervention groups, further research is needed to understand barriers to HPD use and how to maximize the benefits of individually tailored interventions in this setting. In this project we tested the effectiveness of a theory-based intervention (video, pamphlets, and guided practice session) to increase the use of hearing protection devices (HPDs) among Midwestern construction workers and a national group of plumber/pipefitter trainers. Posttest measures were collected 10-12 months following this intervention. Pender's Health Promotion Model (1987) provided the conceptual basis for development of the training program. A total of 837 high-noise-exposed workers were included in the analysis: 652 regional Midwestern construction workers and 185 national plumber/pipefitter trainers. Effectiveness of the intervention was determined through the sequence of analyses recommended by Braver and Braver (1988) for the Solomon Four-Group Design. Analysis of variance and covariance of postintervention use and intention to use HPDs and a meta-analytic test were done. These analyses indicated that the intervention significantly increased use of HPDs but had no effect on intention to use HPDs in the future. Pretesting had no effect on use. Actual or potential applications of this research include guidance in the development of successful theory-based interventions to increase use of HPDs. The effectiveness of a hearing conservation program, and specifically the effectiveness of hearing protection devices (muffs in this case), was investigated over a five-year period, since the inception of the program at a major plant of the Ingersoll-Rand Company. The study concentrated on three groups (Class I, II, and III) of 213 employees whose noise level exposure did not change during the five-year study period. A hearing conservation criterion of 90dBA was utilized. One group consisted of office workers in which the level was well below this, a second group from a machine shop in which the level was slightly below the criterion, and a third group from foundry areas in which the levels were considerably above the 90dBA level. Personal ear protection was worn during the study period only by the last group. The mean differences in hearing levels were insignificant and were essentially the same in the three groups, at each frequency, and regardless of the baseline hearing thresholds. It is apparent that there were no significant changes in hearing threshodls during the study period among a non-noise exposed group; a mild to moderate noise-exposed group; and a group exposed to high levels of steady state noise, but wearing ear protectors. These results indicate that a hearing conservation program which includes audiometric testing and personal ear protection, utilizing a hearing conservation criterion of approximately 90dBA, does adequately protect the hearing of noise-exposed workers. One approach for evaluating the effectiveness of Hearing loss prevention programs (HLPPs) is to compare the rate of hearing loss in a study population with that in a reference population. This approach was used to evaluate the HLPP of a population of 14,900 employees of an industrial company with branches across the United States. Three reference populations were selected from a database of 22 industrial companies compiled under the sponsorship of the National Institute for Occupational Safety and Health. The risk of hearing loss in the study population was estimated relative to each of the three reference populations using the Cox proportional hazards model after adjustment for race, age at baseline, and hearing threshold at time of enrollment in the HLPP. In comparison with the three reference populations, hearing loss was 2.1 to 3.9 times more likely to occur in study population males and 1.8 to 5.1 times more likely in study population females. The 95% confidence interval around each risk estimate precluded unity, indicating that each risk estimate was statistically significant. These results indicate that the performance of the subject HLPP needs improvement. This study demonstrated the use of comparison populations for evaluating the effectiveness of HLPPs. Adolescents working in agricultural settings may be exposed to noise levels that result in hearing loss. The article describes the design, implementation, and results of a four-year, hearing conservation program (HCP) conducted at school. Thirty-four schools (753 students) were randomly assigned to either an intervention or control group. The intervention included multicomponent educational strategies and employed features of an industrial HCP. Final compliance surveys indicated 87.5% of intervention students reported using hearing protection devices (HPD) at least some of the time, compared to 45% of control students. The HCP components with the greatest reported influence were distribution of HPDs for use on the farm and yearly hearing tests. Eighty percent of intervention students reported intention to use HPDs in the future. It is feasible to conduct a hearing conservation program with junior high school and senior high school students, and it appears possible to persuade teen-agers to protect themselves from exposure to loud noise while working on a farm. Advances in computer technology and accessibility enable researchers to provide individually tailored interventions for behavioral change. Using multimedia technology, this study developed and tested a computer-based hearing test and a tailored intervention. The purpose of this study was to evaluate, using a randomized experimental design, the efficacy of the intervention to increase workers' use of hearing protection. The tailored intervention developed by the research team showed more significant short-term effect measured immediately after the intervention than the control intervention. For the long-term effect measured 1 year after the intervention, both tailored and control groups showed significant increase in their reported use (7% vs. 6%) from preintervention to postintervention, but no significant difference between the two groups. The change accomplished in this study was small progress toward the desired level of 100% use of hearing protection to prevent noise-induced hearing loss. This finding showed that changing workers' hearing protection behavior is difficult. A field study assessed the actual spectral noise attenuation achieved by 40 industrial workers wearing four different hearing protection devices (HPDs) while on the job. The effect of two different HPD fitting procedures (subject fit vs. trained fit) on attenuation performance over two three-week periods of protector use was determined. Subjects were retrieved from their workplaces without prior knowledge of when they were to be tested and were not permitted to readjust the fit of their HPDs. Attenuation data were then collected using psychophysical procedures testing real ear attenuation at threshold. Statistical analyses indicated that the earplugs' attenuation significantly improved when training for proper fitting was used, whereas the earmuff and the ear canal cap were relatively insensitive to the training effect. The training was most effective for a slow-recovery foam plug over the three-week period. Results confirmed that laboratory protocols designed to simulate workplace influences on attenuation may not be relied on to yield reasonable estimates of field protection performance of HPDs, particularly for earplugs; however, the laboratory results were much better predictors of field protection for the earmuff. This study also demonstrated that the labeled manufacturers' noise reduction ratings (NRRs) substantially overestimated the actual field attenuation performance. Occupational noise-induced hearing loss (NIHL) is prevalent, yet evidence on the effectiveness of preventive interventions is lacking. The effectiveness of a new technology allowing workers to monitor daily at-ear noise exposure was analysed.
                Workers in the hearing conservation program of an aluminium smelter were recruited because of accelerated rates of hearing loss. The intervention consisted of daily monitoring of at-ear noise exposure and regular feedback on exposures from supervisors. The annual rate of change in high frequency hearing average at 2, 3 and 4 KHz before intervention (2000-2004) and 4 years after intervention (2006-2009) was determined. Annual rates of loss were compared between 78 intervention subjects and 234 controls in other company smelters matched for age, gender and high frequency hearing threshold level in 2005.
                Individuals monitoring daily noise exposure experienced on average no further worsening of high frequency hearing (average rate of hearing change at 2, 3 and 4 KHz = -0.5 dB/year). Matched controls also showed decelerating hearing loss, the difference in rates between the two groups being significant (p < 0.0001). Analysis of a subset of intervention subjects matched to controls for initial rate of hearing loss showed a similar trend but the difference was not statistically significant (p = 0.06).
                Monitoring daily occupational noise exposure inside hearing protection with ongoing administrative feedback apparently reduces the risk of occupational NIHL in industrial workers. Longer follow-up of these workers will help determine the significance of the intervention effect. Intervention studies for the prevention of NIHL need to include appropriate control groups. The effectiveness of a V-51R insert hearing protector in preventing daily temporary threshold shifts in one industrial environment where the employees were exposed to an A-weighted energy average noise level of 95.6 dB was investigated. For comparison purposes the E-A-R Plug Insert hearing protector was also evaluated. The results indicated that the employees who wore the V-51R design incurred significant daily shifts in their hearing levels as compared to their initial hearing exam and significantly greater shifts than the employees who wore the E-A-R Plugs. The greater than expected measured shifts in hearing levels over the past six years in the two departments investigated is attributed at least partially to the use of the V-51R design. (1) To conduct a contemporary analysis of historical data on short-term efficacy of a 3-year hearing conservation program conducted from 1992 to 1996 in Wisconsin, USA, with 753 high school students actively involved in farm work; (2) to establish procedures for assessment of hearing loss for use in a recently funded follow-up of this same hearing conservation program cohort.
                We analyzed a pragmatic cluster-randomized controlled trial, with schools as the unit of randomization. Thirty-four rural schools were recruited and randomized to intervention or control. The intervention included classroom instruction, distribution of hearing protection devices, direct mailings, noise level assessments, and yearly audiometric testing. The control group received the audiometric testing.
                Students exposed to the hearing conservation program reported more frequent use of hearing protection devices, but there was no evidence of reduced levels of noise-induced hearing loss (NIHL).
                Our analysis suggests that, since NIHL is cumulative, a 3-year study was likely not long enough to evaluate the efficacy of this intervention. While improvements in reported use of hearing protection devices were noted, the lasting impact of these behaviors is unknown and the finding merits corroboration by longer term objective hearing tests. A follow-up study of the cohort has recently been started. Noise exposure remains one of the most ubiquitous of occupational hazards. Hearing conservation program legislation and the programs themselves were designed to lower risk of resulting occupational noise-induced hearing loss, but there has been no broad-based effort to assess the effectiveness of this policy.
                The incidence of a 10-dB standard threshold shift was examined in a group of Canadian lumber mill workers, using annual audiogram series obtained from the Workers' Compensation Board of British Columbia for the period 1979-1996 and using Cox proportional hazard models.
                Mean cumulative noise exposure was 98.1 dB-years. The audiograms from 22,376 individuals, among whom there were 2,839 threshold shifts of 10 dB or greater (i.e., a "standard threshold shift"), were retained in multivariable analyses. After adjusting for potential confounders, continuous use of hearing protection, and initial hearing tests later in the study period, the risk for standard threshold shift was reduced by 30%. Risk increased sixfold, however, in those with the highest noise exposure.
                Hearing conservation programs may be effective in reducing overall incidence of hearing loss. In the absence of noise control at source, however, highly exposed workers remain at unnecessary risk.
                Copyright 2008 Wiley-Liss, Inc. Hearing protection devices (HPD) remain a primary method of prevention of noise-induced hearing loss despite their well-known limitations. A three-pronged intervention to increase HPD use was conducted among construction workers and included a baseline hearing loss prevention training, follow-up 'toolbox' (TB) reinforcement trainings, and use of a personal noise level indicator (NLI). A total of 176 subjects on eight sites completed three assessments. Prior to intervention, HPDs were used an average of 34.5% of the time and increased significantly, up about 12.1% after intervention and 7.5% two months after interventions were completed. The increase in HPD use was greatest among the group receiving both TB and NLI interventions; up about 25% from baseline, and this group was about two times more likely to use HPDs than the BL (baseline) training only group. This study demonstrates the mild impact of a well-constructed HPD use training and provides support for the additional use of a personal NLI to increase use of HPDs among construction workers. The most effective procedures for using such instruments require further exploration. The purpose of this study was to evaluate the effectiveness of 2 computer-based interventions and booster messages on construction workers' use of hearing protection. Construction workers (n = 343) were randomly assigned to receive tailored (addressing individual characteristics) or targeted (addressing shared characteristics) education, with or without booster messages, in an experimental 4-group pretest-post-test design. Post hoc message matching compared the value of tailored and targeted approaches. Participants improved use of hearing protection from 42% to 50% of the time they were exposed to noise 1 year post-intervention. Differences between intervention groups were not significant. The significant improvement in use of hearing protection demonstrates that interventions can have an impact on preventing noise-induced hearing loss. Since targeted and tailored intervention groups did not significantly differ in use of hearing protection, and since targeted interventions are less costly to develop, targeted interventions offer greater value. The provision of reinforcements or boosters to interventions is seen as a logical approach to enhancing or maintaining desired behavior. Empirical studies, however, have not confirmed the effectiveness of boosters nor assessed the optimum number of boosters or the timing for their delivery.
                This randomized controlled trial contrasted the effect of four booster conditions (a). 30 days; (b). 90 days; (c). 30 and at 90 days; and (d). no boosters of the intervention to increase the use of hearing protection devices (HPDs).
                A total of 1325 factory workers completed a computerized questionnaire and were randomly assigned to one of three computer-based (tailored, nontailored predictor-based, or control) multimedia interventions designed to increase the use of hearing protection devices. After the intervention, colorful boosters specific to the type of training received were mailed to workers' homes. Posttest measures of use were administered at the time of their next annual audiogram 6 to 18 months after the intervention. RESULTS Repeated measures of analysis of variance (ANOVA) showed a significant main effect for the booster (after 30 days) in the group that received tailored training (F[3442] = 2.722; p =.04). However, in the assessment of the interaction between time (pretest and posttest) and boosters (four groups), the ANOVA did not find significant differences in hearing protection device use for any of the training groups. To assess for significant differences between groups, post hoc comparisons were conducted at the pretest and posttest for the total sample and for the subsample of workers who reported using hearing protection devices less than 100% of the time needed. Sheffé contrasts by intervention group, gender, ethnicity, and hearing ability found no significant changes in the mean use of hearing protection devices for the booster groups.
                Although the provision of boosters represented a considerable commitment of resources, their use was not effective in this study. However, it would be premature to eliminate boosters of interventions. Further study is needed to explore the effects of different booster types for increasing the use of hearing protection devices, and to assess carefully the effects of boosters on other health behaviors in studies with controlled designs. Retrospective analysis of initial audiograms from 21 hearing conservation programs (HCPs) revealed several statistical protocols capable of identifying HCPs of known performance. American National Standards Institute (ANSI) and Occupational Safety and Health Administration (OSHA) protocols clearly identified 3 HCPs known to have demonstrated excellent overall programs. ANSI and OSHA outcomes appeared equivalent in ability to provide early warnings of potentially unacceptable HCP practices. Noise induced hearing loss (NIHL) is among the 10 leading occupational diseases, afflicting between 7.4 and 10.2 million people who work in noise above 85 dBA. Although mandatory hearing conservation programs (HCPs) have been in effect since 1972, this problem persists, as hearing protectors are not consistently used by workers, or may not attenuate to manufacturer's estimates in real world conditions. In this study, information from noise and hearing protection use measurements taken at an automobile assembly plant were used to construct average lifetime noise exposure and hearing protection compliance estimates for use in modeling to predict both total hearing loss and onset of two accepted definitions of hearing loss. There were 301 males and females in this cohort; their mean age was 42.6 (7.2) years, and mean tenure was 14.3 (3.5) years. Average length of follow-up was 14.0 years. There were 16 members of this cohort who had hearing loss at the speech frequencies (defined as an average hearing level > or = 25 dB at 500, 1000, and 2000 Hz). In cross-sectional multivariate analyses, years of employment, male gender, and proportion of time wearing hearing protection were the factors most associated with hearing loss at the average of 2000, 3000, and 4000 Hz (p < 0.0001) controlling for age, transfer status (as a surrogate for previous noise exposure), race, and lifetime average noise exposure. The most consistent predictor of hearing loss in both univariate and multivariate analyses was percentage of time having used hearing protection during the workers' tenure. To evaluate the impact on clinical behavior of a 3-day workshop designed to increase trainees' rates of smoking cessation counseling and reminders about Pap smears in routine consultations.
                Randomized control trial.
                Accredited teaching practices of the Royal Australian College of General Practitioners' Training Program.
                Thirty-four trainees and 1,500 consecutive adult patients ages 16-65 years.
                Trainees randomly allocated to the experimental group participated in a 3-day interactive workshop on disease prevention during their 13-week family medicine term. Audiotapes of consultations with adults conducted by trainees at the beginning and end of the rotation were analyzed blind to compare assessment of patients' smoking status and, for women, date of last Pap smear. A questionnaire mailed to each patient after the consultation also allowed identification of smokers and women overdue for a smear. Consultations with these patients at risk were analyzed for preventive counseling. Inter- and intrarater reliability was calculated for audiotape analysis.
                Preworkshop rates of questions about smoking were low, occurring in 22% of consultations. While trainees allocated to the experimental workshop were more likely to ask a routine question about smoking at the end of the term than those in the control group (P = 0.01), two-thirds of smokers remained undetected irrespective of trainee group and fewer than one in five were advised to stop smoking. Reminders about Pap smears did not change as a result of training and remained low in fewer than 20% of consultations. kappa values demonstrated high reliability of audiotape analysis.
                This direct measurement of clinical behavior revealed that low levels of preventive care provided by trainees are resistant to skills training without reinforcement in clinical practice. In view of the importance of prevention in routine consultations, we recommend continued evaluation of more intensive educational programs. Those withstanding rigorous evaluation could be considered for implementation in similar training contexts seeking to improve the frequency and quality of disease prevention in primary medical care. A hearing conservation program (HCP) must include audiometric monitoring. In keeping with this requirement, enormous bodies of audiometric data have been accumulated. However, only a limited number of methods are available for using audiometric data to assess HCP effectiveness. This study illustrates an epidemiologic method. The risk of developing hearing loss (measured by the standard threshold shift) was compared between study and reference populations using the risk ratio. The study population had an increased risk of nearly 3-fold. Epidemiologic risk comparison methods, using reference populations, offer an alternative to current methods for HCP evaluation using audiometric data. This study examines the patterns and trends in noise exposure documented in data collected by Mine Safety and Health Administration inspectors at U.S. coal mines from 1987 through 2004. During this period, MSHA issued a new regulation on occupational noise exposure that changed the regulatory requirements and enforcement policies. The data were examined to identify potential impacts from these changes. The overall annual median noise dose declined 67% for surface coal mining and 24% for underground coal mining, and the reduction in each group accelerated after promulgation of the new noise rule. However, not all mining occupations experienced a decrease. The exposure reduction was accompanied by an increase of shift length as represented by dosimeter sample duration. For coal miners exposed above the permissible exposure level, use of hearing protection devices increased from 61% to 89% during this period. Participation of miners exposed at or above the action level in hearing conservation programs rapidly reached 86% following the effective date of the noise rule. Based on inspection data, the occupational noise regulation appears to be having a strong positive impact on hearing conservation by reducing exposures and increasing the use of hearing protection devices and medical surveillance. However, the increase in shift duration and resulting reduction in recovery time may mitigate the gains somewhat. A successful habit-building technique, overcorrection, was extended into an industrial type military setting to increase hearing protection usage among airplane mechanics in a high intensity noise environment. Three natural groups were assigned randomly to three conditions: a standard daily safety lecture group (S) for an attention-Placebo control; a leader-directed overcorrection group (A); and a leader-participative overcorrection group (P). Unobtrusive pre-test baseline observations of hearing protection usage established no significant difference among groups. Overcorrection requires persons not using hearing protection to practice repeatedly putting on protection after their failure is discovered by leaders or coworkers. During the application phase, the overcorrection groups successfully increased hearing protection usage over pre-test usage and in comparison to the Standard group which remained unchanged throughout the study. One of the overcorrection groups approached perfect usage. Members of the P group gave higher preference ratings than A group members. There was a decline toward original usage levels once the test was called off.
There is low quality evidence that implementation of stricter legislation can reduce noise levels in workplaces. Even though case studies show that substantial reductions in noise levels in the workplace can be achieved, there are no controlled studies of the effectiveness of such measures. The effectiveness of hearing protection devices depends on training and their proper use. There is very low quality evidence that the better use of hearing protection devices as part of HLPPs reduces the risk of hearing loss, whereas for other programme components of HLPPs we did not find such an effect. Better implementation and reinforcement of HLPPs is needed. Better evaluations of technical interventions and long-term effects are needed.