Monsters shouldn't have distinctive sounds

[Bifford]

There are a lot of scary sounds in the game, but playing through I could quickly tell that most of them were just atmospheric and could be ignored. When a real monster actually shows up, you hear a distinctive moan and music. I then hid somewhere until the music and groaning stopped. It was thus easy for me to tell when it was safe and when to be careful.

What if the monsters did not give off a distinctive sound? What if they gave off one of the atmospheric sounds instead? If that were the case, you could never be sure whether you were safe or whether there was a threat afoot, and you'd be constantly looking over your shoulder.