The game is playable and no more problem with sounds!
Download the FAudio-Builds-master.zip from there: https://github.com/Kron4ek/FAudio-Builds
And place in Downloads or whatever you like. Unzip it.
# Ubuntu 18.04/18.10
# 1. Configure you'r sound to 5.1 channels. Install Steam and SkyrimSE(with Proton 3.16-4 enabled for all games) Other Proton verisons may work and may have gliches.
# 2. Start SkyrimSE, to get autoconfigure, then you can exit.
# 3. Install some required software to get FAudio install script to work. (after this you can remove Wine installation, if you wish, but you will be unable to install)
Install wine and git:
sudo apt update
sudo apt install wine git unzip

Open terminal and change dir to Downloads - where you unzip the FAudio files.
Example:
cd $HOME/Downloads/FAudio-Builds-master
chmod 775 wine_setup_faudio.sh
WINEPREFIX=$HOME/.steam/steam/steamapps/compatdata/489830/pfx ./wine_setup_faudio.sh