earmold

noun
ear·​mold | \ ˈi(ə)r-ˌmōld How to pronounce earmold (audio) \

Medical Definition of earmold

: a device of usually acrylic, vinyl, or silicone that fits within the outer ear, is connected by way of a tube to a hearing aid worn behind the ear, and serves especially to channel the amplified sound from the hearing aid to the ear canal