Ah, you are speaking colloquially. This is a subreddit for people who stutter (i.e., meet criteria for a diagnosis of stuttering). As in a persistent stutter under most conditions. The words you are using to define different forms of stuttering are inaccurate. There is no diagnosis for speech impediment, just for stuttering. Technically the official diagnosis is now called "childhood onset fluency disorder" or adult onset fluency disorder, prior to this it was called stuttering. And stuttering when you are nervous is not related to a diagnosis of stuttering. You are talking about something unrelated to stuttering and unrelated to the purpose of this subreddit - on top of that you are incorrectly using terminology and stating things that could be misconstrued as pertaining to stuttering.