Polyglossia is the first ever human-centred voice assistant designed to break down language barriers in hospitals. Interviews with migrants and their families show that many mistrust, or misunderstand, clinical advice due to difficulties in doctor-patient communication. Using spoken keywords, Polyglossia generates simple animations that provide an additional layer of communication. By overcoming the challenges of language, Polyglossia aims to provide universal clarity to medical treatment and to improve the lives of migrants everywhere.