Requires Training: No.
Listen alerts a character to hidden creatures that may be nearby.
Check: Listen detects hidden creatures by opposing their Move Silently check. A successful check renders the hidden creature visible, and makes it a valid target for the listener.
Special: Standing still provides a +5 bonus to a Listen check. A character with the Alertness feat gains a +2 bonus on Listen checks. Rangers gain a bonus when Listening against a favored enemy. Elves, gnomes, and halflings gain a +2 racial bonus to Listen checks. Half-elves receive a +1 racial bonus.
Use: Listen is part of the Detect modal action. In Passive Detect mode, checks are made automatically every round. Active Detect mode is a modal action that reduces the normal movement rate and makes the character perform an Active Listen, as well as Spot and Search checks.