Ear Gauging - Earphones - Oh.. Now I get it ! :-)
It's trendy right now to wear pierced earrings fashioned from plugs or with thick, decorative posts and rings. Even if your ears were pierced to a standard size, you can stretch the holes using a gradual process that is commonly referred to as gauging or simply gauge. Piercing pros will tell you that is not the correct term, but it's become the word most people use to describe the stretching process.
Text source: http://jewelry.about.com/od/bodyjewelry/a/gauging_lobes.htm