Trumpets such as this were once used in Fon rituals “to promote the reincarnation of royal children” and “during royal funerals and ‘huetanu’ rites”. Fon arts often include ideographs that can be “read’ or that refer to praise names of royal families or particularly storied individuals.
Source: DjeDje, J. C. (1999). “Turn Up the Volume! A Celebration of African Music”, Los Angeles: UCLA Fowler Museum of Cultural History. page 309