Disable music:
Press Start in the inventory screen.

Disable sound effects:
Press Start(2) in the inventory screen.

Hint: Safe areas in facility:
If you are being chased by aliens, just enter a vent shaft or run into the infirmary (the starting room of the game). The infirmary is a good choice to use as a "base" because it is in the center of the facility (and aliens will not enter it). Please note that an alien can not open the door, but an alien will enter the infirmary if you move near the door to open it. Make sure that you look carefully at the screen before you open a door.

When you open the door with the blowtorch, you will notice that there is another door in front of you. As long as you do not open this door, you will be safe. However, there will sometimes be an alien in this area.

Hint: Using the flamethrower:
The flamethrower can only destroy alien eggs.