Patent ID: 7418105

Claim:
A stretchable sheath for at least partially covering a core-form of an in-ear device to define a spacing between said sheath and said core-form into which a malleable settable compound may be introduced and held to match a contour of at least one of a cavum concha and an ear canal of an ear with said in-ear device at least partially inserted therein to provide an optimized in-situ adjustment and fit of said in-ear device, a portion of said sheath forming an exposed surface of the in-ear device comprising: at least one lower thickness portion of a first thickness; and at least one augmented thickness portion of an augmented thickness compared to said first thickness and located in an area in which less said settable compound is desired for said optimized fit, said augmented thickness impeding settling and flow of settable compound in said spacing adjacent said augmented thickness portion compared to said spacing adjacent said lower thickness portion.