I have found a solution for slow gameplay with slow/stuttering audio in the first Alone in the Dark game which is really simple and appears to work so far. I assume it will work with the other titles as well and possibly with other games that have similar problems which are using DOSBox to run the game.

Start the game up and once the slow jumpiness with stuttering starts, press CTRL+F11 on the keyboard to slow down the DOSBox emulation and wait 1-2 seconds to see if the stuttering goes away. If not, press it again and count how many times you pressed it so you know how many times you need to do this next time. You can also press CTRL+F12 to speed up DOSBox which I found made the problem even worse on my system.

I am using a 2.4GHz Pentium 4 Northwood with 2.25GB of RAM and Intel i865 onboard video and this solution I stumbled upon randomly and it just so happened to work. It makes the game totally playable and flawless so far and I know several other people playing this game have encountered this problem and reported it on the forums, so please point them to this message if anyone else encounters the issue as it very well may fix the problem.

GOG: Any chance of getting this setting integrated into the GUI configuration for the game at all, or at least in the game documentation/troubleshooting tips section? Just an idea!

Anyhow, this solution makes this classic game totally playable on my system just like it was in MS-DOS originally back in the mid 90s. I hope this helps other classic gamers to enjoy this title as well!