This achievement was a pain.You need to listen to all pages from the journal in one playthrough to get this achievement. At this point there is a few tactics how to get this achievement that can be found in steam guides. But some of this informations are incorrect or could be misleading. To clear this (buggy and unclear) achievement I can share how I got this achievement today. I won't go into details of the game cause this may contain spoilers and you will probably get most of the achievement before getting this one so you will know the game. I was progressing through the stages and end up near the end of the game in the room with cross on the bed. By that time I had 21 pages cause having them is necessary to progress. I didn't picked the cross and I started listening to audio of the pages. IMPORTANT note is that when I opened journal the generic page was the third page not the first one! so be sure to skip to the left to the very first page. Then I started to listed to every page until the girl is done talking + a few extra second after every page to make sure it's registered as listened. I listened to all 21 pages and when I quited the journal immediately achievement popped up without listening to the last 22th page at the end of the game. The reason might be that I listened to this page before (when achievement didn't unlocked) and I Loaded last save to try again the whole process. My first try was a failure cause I didn't noticed that i started listening to pages from the third page. Also it proves that saving and loading do not void the achievement.
Easy "A Musical Interlude" Achievement
You can usually find a radio on a table in the corridor after you break open the door with the axe. If not, you can find several others scattered randomly in the level. Stand next to a radio for thirty seconds. Try to get this as early as possible, as you do not want to be standing still idle after the Hat Man appears.
Easy "Ghost Hunter" Achievement
The shadow people will only appear in your daughter's bedroom after you open her diary. You must kill them with your flashlight. The kills are cumulative and can be done over multiple playthroughs. About 40 seconds are required for each shadow person to appear. Wait in a corner of the room. When you hear them appearing, sprint to the other side of the room then spin around and shine the flashlight on them. They often will materialize behind you.
Easy "Paranormally Active" Achievement
The shadow people will only appear in your daughter's bedroom after you open her diary. You must kill them with your flashlight. The kills are cumulative and can be done over multiple playthroughs. About 40 seconds are required for each shadow person to appear. Wait in a corner of the room. When you hear them appearing, sprint to the other side of the room then spin around and shine the flashlight on them. They often will materialize behind you.
Various Steam Achievements
Complete the indicated task to unlock the achievement.
Achievement
How to unlock
A Good Book
Listen to your daughter read all the pages of her journal in a game.
A Musical Interlude
Listen to the radio for 30 seconds.
Brisk Walkthrough
Finish the game in under an hour.
Cheating Death
Be in the same room as the Hat Man 10 times.
Ectoplasmic Entity
Finish the game without loading a saved game.
Ghost Hunter
Kill 4 shadow people with the flashlight in the bedroom.
Paranormal Expert
Finish the game in under 30 minutes.
Paranormally Active
Run into 50 shadow people.
Psychic Intuitive
Finish the game in under 45 minutes.
Soul Survivor
Save your daughter and escape.
Superior Apparition
Finish the game without loading a saved game and without saving along the way.
Easy "A Good Book" Achievement...