RESUMO
The purposes of this investigation were two-fold: (1) to determine whether differences between measured ear canal diameter and actual earplug size affect sound pressure levels in the ear canal during exposure to high levels of noise; and (2) to determine if individuals would select the insert earplugs that conform to their measured ear canal diameter if the decision were left to them. The results indicate that: (1) very small differences between measured ear canal diameter and actual earplug size affect considerably the sound pressure levels in the ear canal during exposure to high levels of noise; (2) individuals typically select earplugs that are smaller than their measured ear canal dimensions when the decision is left to them; (3) the most skilled technician cannot always determine ear canal sizes due to limitations of available measuring instruments.