Examples of retaining seal assemblies for acoustically sealing and retaining a canal hearing device or an earpiece within the ear canal are disclosed. The retaining seal assembly may include one or more flanges and a clip element. The flanges may include elongate trenches along an exterior surface of one or more of the flanges. The elongate trenches may allow the flange to conform to the shape of the ear canal and distribute concentric compressive forces when the seal assembly is inserted in the ear canal. The clip element may be formed of a relatively rigid material and may include one or more locking tabs. The conforming flanges may be concentrically positioned over the clip element. The seal assembly may include a debris barrier to provide protection for a sound outlet of the canal hearing device or the earpiece.