Enhanced hearing expands the functionality of listen allowing you to 'listen all' this requires a challenging perception check, but if successfull provides a list of nois producing objects in the room such as creatures. This can allow certain races to target hidden or invisible creatures by virtue of the sound they make.
Example:
"It sounds like you are indoors.
You hear the following:
a humanoid"
The humanoid could be attacked using "kill humanoid" even without seeing what it was. In this case the humanoid had to be targetted with "kill humanoid 2" because "humanoid" was interpreted as the player.
Races with enhanced hearing: Arakun, Atomy, Behemoth, Bloodworm, Catfolk, Changeling, Dhampir, Dragon, Dragonian, Elf, Flynd, Leprechaun, Muridan, Selkie, Tortle, Unicorn, Vampire, Vulpin, Werewolf
Certain equipment provides enhanced hearing when equiped.