That is something that is out of the ordinary,
The story about The Exorcism Of Anneliese Michel is about one of the most leading exorcisms out there.

A woman who underwent 67 Catholic exorcism rites during the year before her death,
She had mental illness that also affected her well being, there are recordings of the exorcism and the sounds are horrifying and scary, just like what a demon would say and speak.

It is explained that after the demon took over Anneliese's body, he wouldn't let her drink or eat, he starved Anneliese till it drained her life.

I've attached a video explaining about the story of Anneliese Michel and the recordings that can be heard (very eerie).

https://www.youtube.com/watch?v=-4xiT67GrbY&t