Figure 1: Extraction force of 5 different earplugs from artificial ear canals. There is a general trend for the extraction force to decrease with increasing canal size. However, some plugs (the Quiet mushroom) seemed to be only acceptable for the median ear canal. The Decidamp foam cylinder produces about the same force for all canal sizes. Missing points indicate that the canal was either too large or too small for the earplug to be able to fit.