An earmuff hearing-protection device (1) including a non-porous, sound-attenuating body (50) disposed within an interior space (31) defined by a shell (30) of an earmuff of the device, the non-porous, sound-attenuating body including sound-attenuating members (100) arranged and spaced to define a set of high aspect ratio air gaps (e.g. 300) between major side surfaces of neighboring members.
