1. A pair of speakers inside pads which you wear over your ears in order to listen to a radio, record player, or tape recorder without other people hearing it. English = headphone, headphones, head-set.
2. A medically trained person whose job is to test people's hearing, especially for any evidence of hearing loss. English = audiologist.
3. The study of people's hearing, especially the testing of people's hearing for any evidence of hearing loss. English = audiology.