Sure, praying is an act for someone who wants to speak to himself in his mind.

I heard this tough but very gentle man speak to me in my mind.

I've got a pretty good idea of who he is, but I don't want to start speaking any names in my mind, you understand?

He can even hear "her" speaking to him in his mind.

I would like that book, he told the skull, speaking in his mind.

The voice which had spoken in his mind was silent.

At the same moment, a voice spoke in his mind.

"Most of you find it less disturbing than when I speak in your mind."

But the same voice was speaking in her mind as well.

"I rather doubt he's ever heard anyone speak in his mind before," she pointed out.