That depends if they are listening as an action (in which case they could take 10 or even 20) or by a judgement call by the GM, depending on circimstances...

The player(s) can always *tell* you that they want to make a "listen" check, but whenever the PC's "might" hear a (significant) sound, the GM should TELL them to roll (or roll secretly FOR them).

Note that "listen" (and other "always-on" senses) are different than many skills. People who fail to notice a sound won't KNOW that they failed to notice the sound... but people who fail to unlock a door WILL know that the door is still locked... ;-) So, for exmple, the GM would seldom (if ever) tell the players, "OK, I need open locks rolls from everyone..." but it could be quite common to hear "everyone make a Listen check..."


- Steve

Beginners wouldn't call it but I think the DM may translate it as such. It would take some story-telling skill. Probably send the special-ed kids on the bus away to begin.