The B'Nar is a Talarian ritual, also called "The Mourning".

It consists of a high-pitched shriek and rocking back and forth for a considerable time-span. Jono performed the B'Nar while being treated in sickbay aboard the USS Enterprise-D and later when he was separated from the other teenage Talarians rescued from a derelict Talarian observation craft. (TNG: "Suddenly Human")