average of 60% of individuals with cleft without prs. another study with children showed that hearing loss was found more frequently with prs (73.3%) compared to those with cleft and no prs (58.1%). hearing loss with prs typically is a bilateral, conductive loss (affecting the outer/middle portion of the ear). history the condition is named for the french dental surgeon pierre robin. it is thought that noel rosa, one of the most famous and influential artists in the history of brazilian music, had prs, although others claim that his sunken chin was the result of a forceps accident during childbirth.