Verifying earplug attenuation and evaluating the effectiveness of one‐on‐one training along with earplug fit testing at nine facilities in China

Abstract

Background The purpose of this study was twofold: (1) to measure the personal attenuation ratings (PARs) in Chinese workers wearing hearing protection devices (HPDs), to evaluate the effectiveness of the single number rating (SNR), the noise reduction rating (NRR), and the associated derated values of earplugs; and (2) to evaluate the effectiveness of one‐on‐one training along with earplug fit testing on PAR improvement. Methods Noise exposure measurements, one‐on‐one training, and fit tests to measure earplug attenuation were conducted at nine manufacturing facilities located in eastern China from 2016 to 2017. 503 workers participated in the study. Ninety‐three percent were male. 199 workers were provided one‐on‐one training. Results Before training, 14% and 15% of the workers achieved the attenuation predicted by the manufacturer's SNR and NRR, 56% and 65% exceeded the derated SNR and NRR, respectively. Following one‐on‐one training, mean PAR improved significantly by 15 dB (p < 0.01); 26% of the workers achieved SNR and NRR, 79% and 91% met the associated derated values, respectively. Conclusions Labeled noise attenuation ratings and their derated values overestimated the actual level of attenuation among workers wearing HPDs. One‐on‐one training along with earplug fit testing contributed to improved PARs.

Improving Hearing Protection Device Noise Attenuation Through Fit-Testing in an Occupational Health Clinic

“…Similar to other findings, the results in this QI project demonstrated that HPD fit testing was an effective method for training employees to properly insert HPDs (Federman & Duhon, 2016; Federman et al, 2021; Gong et al, 2019, 2021; Murphy et al, 2016; Sayler et al, 2018; Smith et al, 2014). In addition, this project showed that an evidence-based practice (i.e., using HPD fit testing to validate expert-fitted HPDs followed by participant return demonstration of self-fit using muscle memory to replicate proper fit) outlined by Federman and Duhon (2016) could be successfully implemented by staff in an occupational health clinic.…”

“…Time to conduct fit testing varies by system and with the number of trials an individual needs to achieve appropriate PAR. Time to complete fit testing using FitCheck Solo™ in this project was comparable to other studies using this system showing minimum time of 5 minutes for baseline testing and maximum of 30 minutes for up to four fit tests (Gong et al, 2021; Michael and Associates, n.d.; Murphy et al, 2016). Considering cost of equipment, personnel and time, the cost–benefit ratio for a 20% improvement in participants who achieved target PAR appears worthwhile.…”

“…It is possible that 20 dB of attenuation may represent overprotection for noise exposure, especially if participants worked in low to moderate levels of hazardous noise. For safety-sensitive jobs where hearing is critical, a fit-testing program provides a way to tailor the HPDs to the noise levels encountered ensuring employees achieve target protection that allows for safe listening and situational awareness (Gong et al, 2021; OSHA Alliance, 2008; Sayler et al, 2018). Overcoming the barrier of determining the actual noise attenuation needed on an individual basis is crucial to avoid both under- and overprotection.…”

“…Generally, HPDs should attenuate noise to around 75 dB to maximize ability to communicate and allow workers to hear alarms and warning signals (Sayler et al, 2018). Since overprotection can be as significant as under protection from hazardous noise, understanding how hearing loss affects HPD noise attenuation is a critical area that requires further study (Gong et al, 2021; Sayler et al, 2018).…”

“…The authors’ findings indicated that expert HPD fitting and participant return demonstration with fit-test validation was an effective training method that significantly improved PARs (Federman & Duhon, 2016). Studies by Gong et al (2019), Gong et al (2021), Sayler et al (2018) and Ullman et al (2021) have confirmed that HPD fit testing is an appropriate training method to ensure proper HPD fit and prevent occupational NIHL.…”