Ok, I didn't write this, someone on Mark's channel in the comments did (I forget their name, sorry) but they came up with this:

"Can you imagine the fact that I don't know which I'm supposed to be in? Why don't you go rule me on it. Same old few things as ever. You under the table trade off punts. Can you understand me? Nobody does. Listen, there is a body at the door. Should I get rid of him? Find me at grave field"

Since the person has receptive aphasia it's more of "what are they trying to say" instead of "what does it mean"

467767 spells HORROR look at the mobile keypad

credits Lolrs 64

http://imgur.com/a/tbEmY .

NEW DISCOVERY:

Inside the exe files, if you paste them into notepad and turn on Wordwrap under Format, mess with the window size, you get an ASCII art of the icons for the games,

Proof:

Credit to Blondebro7 for discovering this!

Just saying.

This is all I believe it's worth taking from the game, regardless of any hidden message. Even if there is, and I'm pretty sure there isn't, doubting the conclusion just enforces it.

i think i found something in the .exe files. Unknown Developer What engine did you use to create this? i would like to delve deeper into the coding of your creation

L.-.. O--- O--- K-.- I.. N-. S... I..D-.. E.

You say they're not viruses.

But my anti-virus keeps blocking me from opening the file, then deletes it, claiming it to be malware.

Is there any way around this? Or do I just have to deal with it?

I Found a TON of secrets. (I THINK!) no spoilers here, but if you want to play this game series, just know that you will have to make ALOT of notes... so, y'know, keep a pen handy. and maybe a dictionary jus saying! ;)

Okay, so from the things I read I think I found a solution.

The speaker seems to have symptoms of an aquired language disorder.
She's saying this:

"Can you enlighten the fact, I don't know which for sim-pasta mosting?
Why don't you go gruel on it?
Same foldgen as ever.
Hover the tablecloth punk.
Do you understand me? Nobody does.
Listen. There's a bodgins at the door. Should I garest him? 
Find me a gromph reil." (or this is what I heard)

If she has that language disorder, then I guess this is what she should be saying:

"Can you imagine the fact that I don't know which I'm supposed to be in?
Why don't you go rule me on it. 
Same old few things as ever.
You under the table trade off punts.
Do you understand me? Nobody does. 
Listen, there is a body at the door. 
Should I get rid of him? Find me at grave field"

So, as many of you found out, the letters might form a 'code'

A = 1
B = 2
...
Z = 26

26 * 30 (the number of letters) = 780
I guess if you manage to have the 30 Zs, then you might have a jumpscare of the body and the one that murdered him/her. 
This is my guessing, I don't know very well.

Anyways, I think the games have a story behind it. I haven't played them yep, but I'll do as soon as possible

this is a very interesting game