You will hear it used mostly in fiction predominantly by working-class male characters (period dramas come to mind first) and when used in fiction it is often fairly clearly pronounced .
In real life, is not pronounced clearly as in fiction. It is more often what can sometimes _**sound like**_ rather than how it is actually pronounced intentionally. Another way it can be perceived is . You will hear these mostly around Tokyo and not really in western Japan.
I would say that the reason for the clearer pronunciation of in fiction is its function as []{}("role language").
In real life as well, these variations of is used by older _**male**_ individuals around Tokyo. That is used only by female speakers is just a rumour in the Japanese-as-a-foreign-language world. Do not trust it.