Can a 16 year old male get rid of an R impediment?

by Joseph
(Utah)

I'm a 16 year old male, who has had an R impediment when I talk. I took speech therapy in elementary school for I think 3 years, grades 3rd-6th. and started to take it in 7th grade until I wanted to stop. I was never motivated to work on it, and therefore made no progress. And I honestly just went because they gave out candy. over the recent years I've thought about trying to get rid of it, and how I might do so. But I'm lost in the whole process and don't know much about how to change my voice. My older brother also has the same impediment and I've wondered if it might be connected genetically. I don't know if that is related at but I think it might help you answer my question.