First off, you'll need an .ogg file. The way to create this is to have an audio file, does not matter wich one, open it in Audacity and Export it in your custom story's sound folder as .ogg extension.
Now right click and 'New->' and then .txt file.
Rename the .txt file to the name of your sound (example my name is lol.ogg, rename it to New Document.txt (or something) to lol.txt) open lol.txt and paste in:
<SOUNDENTITY>
<SOUNDS>
<Main>
<Sound File="lol.ogg" /> <!--here comes the name of your sound, mine is lol.ogg, keep the .ogg extension --> </Main>
</SOUNDS>
<PROPERTIES Volume="5" MinDistance="1" MaxDistance="50" Random="0" Interval="0" FadeEnd="False" FadeStart="False" Stream="False" Loop="False" Use3D="false" Blockable="False" BlockVolumeMul="0.7" Priority="5" /> <!-- Keep this, only edit if you know what it means --></SOUNDENTITY>
now Press Save-As and save it as lol.snt (click 'text document (*.txt)' and select 'all files (*.*)')
Now you made a fully functional sound file for Amnesia: The Dark Descent.
I assume you know how to make a Script Area, (if not search the tutorial) and the callback func to do that
PlaySoundAtEntity("", "lol.snt", "Player", 0, false);
The first Variable is the Name of the sound, just the name, its not very usefull.
The second variable is the Name+Soundfile (.snt extension)
The tirth variable is the entity to be played at, Stereo speakers or 5.1 speakers are really cool for this. Player makes it do for all.
The rest you don't really need
Thanks for checking this Tutorial, goodbye
!