Listen

(Wis) Check Your Listen check is either made against a DC that reflects how quiet the noise is that you might hear, or it is opposed by your target’s Move Silently check.
In the case of people trying to be quiet, the DCs given on the table could be replaced by Move Silently checks, in which case the indicated DC would be their average check result.
Action Varies. Every time you have a chance to hear something in a reactive manner (such as when someone makes a noise or you move into a new area), you can make a Listen check without using an action. Trying to hear something you failed to hear previously is a move action.
Try Again Yes. You can try to hear something that you failed to hear previously with no penalty.
Special When several characters are listening to the same thing, a single 1d20 roll can be used for all the individuals’ Listen checks.
A fascinated creature takes a -4 penalty on Listen checks made as reactions.
If you have the Alertness feat, you get a +2 bonus on Listen checks.
A ranger gains a bonus on Listen checks when using this skill against a favored enemy.
An elf, gnome, or halfling has a +2 racial bonus on Listen checks.
A half-elf has a +1 racial bonus on Listen checks.
A sleeping character may make Listen checks at a -10 penalty. A successful check awakens the sleeper.
Listen DCs:
Sound/ Listen DC
A battle_-10
People talking*_0
A person in medium armor walking at a slow pace (10 ft./round) trying not to make any noise_5
An unarmored person walking at a slow pace (15 ft./round) trying not to make any noise_10
A 1st-level rogue using Move Silently to sneak past the listener_15
People whispering*_15
A cat stalking_19
An owl gliding in for a kill_30

Listen DC Modifiers:
Condition_Listen DC Modifier
Through a door_+5
Through a stone wall_+15
Per 10 feet of distance_+1
Listener distracted_+5