I can only respond for myself, dear Ataloa (peace to you, dear one!).
When I pray to the Father, I do as my Lord directed: in private (
Matthew 6:6). That I should pray so (in private, door shut), means I would be speaking out loud... or at least loud enough so that anyone near could hear... else, why the need FOR privacy? Who can hear you speaking "inside" yourself? He didn't tell us to do something HE didn't do, though: HE
always prayed to the Father in private. That is why he ALWAYS went AWAY from his disciples WHEN he prayed (a stone's throw away, out on a boat, etc.).
True, he often gave THANKS in front of his disciples; but that is NOT the same as prayer. "Thanks" is acknowledging something the Father has done/given. "Prayer" is when one is beseeching the Father FOR something. So Christ did give thanks publicly. But he
prayed to the Father...
out loud... and virtually always in private.
Now, some will say, "Well, if he prayed in private, how did John et al.
know what he SAID?" But that's the thing: they knew... BECAUSE he prayed to the Father OUT LOUD. He went AWAY from them to do so in private, but was
followed. It was only on the VERY rare occasion that he would pray in front of others. For example, when he was dying on the pole.
In speaking to my Lord, however, it is something that I may do out loud OR in silence. Either way, I do not do it with my "lips", technically (although my lips might manifest my efforts, literally): it is "spoken" with every fiber of my being. It does not
require outspoken words, though; indeed, sometimes, it doesn't require literal words at all... because sometimes we don't KNOW what words to USE... what to say/ask for. In which case, our SPIRIT "pleads FOR us with words UNUTTERED"... words that can't BE spoken.
Romans 8:26 Our spirit... OR blood... pleads... to HIS: his spirit... blood... holy spirit... that is IN us.
The life... OUR life... is in our blood. Christ is the Life; therefore, by means of holy spirit, HE is in our blood. Because HIS blood... which blood he received from his Father, the MOST HOLY One of Israel, JAH of Armies... comes to be in OUR blood. Our blood, then, speaks to him (it also speaks to humans - what the blood "says" is how we often know how health or sick a person is... or what they have in the vessel - i.e., how much alcohol, glucose, poison, etc.). We need special tools/instruments to "read" blood, to "hear" what it says. God and Christ do not.
So, unless he speaks to one OUTSIDE of the vessel that is the body of flesh (which he also does and I marvel that some here profess a faith in certain "saints" who make such claims but deny that same spirit today!)... his voice is heard "inside". NOT in one's head... but in one's EVERYTHING: blood, tissue, hair... everything. And when it speaks LOUDLY... one can
feel it "speaking." Similar to what one feels when a voice reverberates in the physical realm.
He listens to US, dear one. We, though, don't always listen to HIM. FAITH...
in him, however... that he DOES speak and WILL speak... and that what we hear that we know is from him IS from him (so that we don't talk ourselves out of it - LOLOL!)... is "how" we hear him, dear one.
Why? Because he SAID he would be with those who belong to him... and that HIS sheep WOULD hear, know, and listen to his voice. If one has FAITH in him... that what he said is TRUE... then one will hear him.
If, however, one listens to "men" who say, "Oh, no, God and Christ don't speak directly, no, one must read the Bible, God speaks through the Bible, the Bible is God's word, etc.

" then one is NOT putting faith
in HIM... and what HE said... but what those... whose aim is to mislead, if possible, EVEN the chosen ones... say.
It really boils down to a choice, dear one... as to WHOM one will listen to: Christ, who said HIS sheep hear his voice... or those who say, no, no one does (well, unless THEY approve such one).
I hope this helps, truly, and again, peace to you!
YOUR servant and a slave of Christ,
Shellama