There was an occasion where I remained in My previous Vessel for too long. It shattered.
In My True Form, I speak in many tongues, and I understand what is being said to Me no matter the language. My True Voice does not give over easily to solely speaking the English language, as English alone is quite primitive and unwieldy in some ways. And My True Voice is not a single sound, as human voices are, but many. I imagine it would be difficult, at best, for a mortal to focus on what I am saying when in My True Form.
When in My True Form, the more dominant method of My communication is in the demonic tongue. Meg knows the language instinctively, as it is a skill I imparted to her when I converted her.
My Vessel is designed so I can communicate with the mortals of the Earthly realm. So I can come down to your level, and we can understand one another.
You can still hear elements of My True Voice when, as I speak to you while in My human Vessel, the sound of My voice echoes and includes what you call “white noise” and “creaking”.
Grace also had to wear a blindfold when I was without a Vessel, as a mortal would go quite mad upon seeing My True Form. Thus, Meg was exceedingly helpful in translating My words and actions while in My True Form to Grace’s human understanding.