Monsters shouldn't have distinctive sounds

[Mjarr]

I'm positive the ones in the Choir at least are persistently wandering around.

Basically everytime you hear the distinguishable "BLEARGH" or "MOO" sound it means the enemy spawns, and if you wander around in the Choir (presuming I remember the place right) long enough it becomes painfully obvious that basically on certain spots no matter what you do, you can hear that the enemy has spawned.