CleverRaven/Cataclysm-DDA — pull request #3657 by CIB (2013-10-15 11:58:07+00:00)
Title: Hearing is now "inaccurate" if the volume of the sound is low.

Tested this quickly by sneaking through the night with zombies around. The result is interesting: Zombies will come running in "roughly" your direction, but can easily miss you in the dark.