Discrepancies between attenuation obtained in the laboratory and the field are caused by several factors associated with hearing protection devices (HPDs). The effects of some factors can be minimized with proper training provided to HPD users.To evaluate the effectiveness of an educational intervention for improving the correct use of earplugs as HPDs in workers exposed to occupational noise by using the F-MIRE method and by comparing pre- and post-training attenuation values and pass/fail rates.The personal attenuation ratings (PARs) of two types of earplugs were obtained (140 individuals) using E-A-Rfit™ equipment. Each HPD was evaluated under two scenarios: first after the user only read the packaging instructions, and then after the user read guidelines and participated in a training program. The results obtained were automatically classified by the software as "Approved" or "Failed".There was a significant post-training increase in the binaural PAR values for both HPDs. The percentages of passes pre- and post-training showed that training users in the proper fit of the HPD was effective; both types had statistically significant differences.This study found a statistically significant increase in PARs and the number of workers passing evaluations after HPD fit training, demonstrating the effectiveness of this educational intervention.