Enhancing and Sustaining Noise Attenuation from Hearing Protection Devices: A Mixed Methods Review of Fit Testing and Instruction Approaches

Details

• Personal Author:
  Gong, Wei ; Morata, Thais C. ; Samelli, Alessandra G.
• Description:
  Extensive training has been shown to improve the effectiveness of hearing protection devices (HPDs) in reducing noise exposure for workers. This study aimed to (1) assess the evidence for short- and long-term effectiveness of HPD fit testing paired with extensive instructions and (2) identify the type and frequency of refresher instruction associated with maintaining its effectiveness. A literature search was completed on February 5, 2025. The inclusion criteria focused on uncontrolled before-and-after (UBA) studies that reported personal attenuation ratings (PARs) provided by HPDs in the field. A total of 23 UBA studies involving 5,575 workers were included, meta-analyses were performed when multiple comparable studies were located. For earplugs, retesting immediately after extensive training increased the mean PAR by 12.88 dB (13 studies) compared with the pre-intervention PARs without instructions. The improvement decreased to 8.84 dB (2 studies) within 6 months and further reduced to 4.46 dB (2 studies) at 12 months. For earmuffs, only one study reported increase in PARs of 5, 2, and 3 dB for immediate, short-term, and long-term assessment, respectively. Introducing extensive refresher training within a 6-month interval increased the mean PAR from earplugs by 1.53 dB (2 studies) compared with the post-intervention PAR retested immediately after extensive training, with a further increase of 3.45 dB (1 study) following annual extensive instruction. Simple refresher instructions within a 6-month interval maintained the PAR values (1 study). However, without any refresher training, the PAR decreased by 2.64 dB (2 studies) within 6 months and 3.09 dB (2 studies) over 6 months or longer. Refresher training may increase the probability that workers receive efficient protection from their HPDs. However, more high-quality studies could help inform the optimal type and frequency of refresher training.
• Subjects:
  Noise, Occupational Occupational Health Personal Protective Equipment Safety
• Keywords:
  Author Keywords: Earmuff; Earplug; Hearing Conservation Program; Hearing Loss Prevention; Personal Attenuation Ratings; PARs; Training Hearing Protection; Noise Exposure; Hearing Conservation; Hearing Loss Prevention; Ear Protection; Training;
• ISSN:
  1545-9624
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Ohio ; Chicago Region [OSHA]
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DFSE - Division of Field Studies and Engineering
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  16 pdf pages
• NIOSHTIC Number:
  nn:20071079
• Citation:
  J Occup Environ Hyg 2026 Jan; :[Epub ahead of print]
• Email:
  yud9807@gmail.com
• Federal Fiscal Year:
  2026
• Peer Reviewed:
  True
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c225d598692e31271a08fbd186dc73872c3dcf02652762b5d525e183b1c6060d2f6a14a90ee52371b553f003aaff75dadaec85d8a60fffed187c9dfd016f5e98
• Download URL:
  https://stacks.cdc.gov/view/cdc/257855/cdc_257855_DS1.pdf
• File Type:
  [PDF - 1.59 MB ]