I believe he was whispering something.

He made his way to the door carefully, without stumbling against anything or knocking anything over; he opened the door a very little way, and squeezed through almost sideways.

As he went out his shock of hair standing on end at the back of his head was particularly noticeable.
Then first of all one fearful scream was heard.

I saw Lizaveta Nikolaevna seize her mother by the shoulder and Mavriky Nikolaevitch by the arm and make two or three violent efforts to draw them out of the room.

But she suddenly uttered a shriek, and fell full length on the floor, fainting.