Insertion loss values of earplugs

Abstract

The purpose of this study was to investigate the feasibility of measuring the insertion loss (attenuation) provided by cannon earplugs using the Knowles Electronics Manikin for Acoustic Research. Five earplugs were tested in a 90 dB sound field at discrete frequencies matching those published by NIOSH. Each plug was exposed to 10 trials. Results indicate an approximation between values obtained in the study and NICSH published values. Some consistent differences tend to indicate that NIOSH values may overrate low frequency attenuation