For example if somebody is saying: "Ooooooh myyyyyyy Gooooood" or if they realize something and go "Ooooooh!" or Darth Vader's "NOOOOOOO!", usually all of these extra vowels aren't included in the words(you won't find it in a dictionary), but does this phenomenon of multiplying have a name or a term?
I've got a hard time formulating the description to be short enough for google to help, so even if you don't know if there is a word for it, help with description/formulation would be appreciated too.