Instructions
Open the "Options" menu for the game.
Single click with your mouse on the "Keyboard/Mouse" option.
From the "Keyboard/Mouse" screen, select the check box next to "Enable" under "Allow Developer Console." This will allow you to open the developer console in the game and alter the character's voice abilities.
Press the "~" key on your keyboard to open the developer console.
Select a letter you want to use to make your character scream, such as "t." Type the following phrase on your keyboard:
bind t "vocalize playerdeath"
Single click "submit." This will bind the letter you chose to the screaming action.
Open the game to test the settings. While your character is in action, press the key you chose. If your character does not scream, repeat the steps above using a different key.