Entities 220: Lesson 3
Special Auditory Effects (target_speaker)
Sound is yet another major cornerstone in any quality map. Nothing satisfies a player more than the click of a button or the cold hum of a bunch of computers. But how do we add these things when they're not entity-based? target_speaker!
Since our fx_runner is also still silent, we need to add a target_speaker to it. Make one and place it physically on top of the fx_runner. Then add the key noise and the value sound/effects/flamejet_lp.wav. Check the LOOPED-ON checkbox to make it repeat infinitely. That's it!
A note of warning, however. You cannot loop MP3s in MP. There is no real specific reason for this; it just doesn't work. If you reference an MP3, you will get a "sound cannot be streamed" sort of error when you try to load your BSP in the game. If you wish to loop a WAV, simply place the target_speaker without any flags set and the key wait and however long you want it to delay between fires. You cannot, however, fully loop sounds in MP. It simply cannot be done - the closest you can get is with a 1 second pause between firings, with the wait flag set.
target_speakers can be triggered just like dynamic lights can - so if you want to trigger a fx_runner and a target_speaker together (making a switchable flame jet, lightning, or other such object), you can! Just attach them both to a trigger_multiple and have at it.
If you want a global sound (like rain or lightning) you can also check the GLOBAL flag. An interesting feature there (for example, if you wanted lightning) would be to add the key wait (to cause a delay between firings) and then the key random. Then sound will then fire every wait number of seconds, plus or minus random seconds. This could be useful if you wanted to create randomly striking lightning sounds. (This is how lightning was triggered in duel_kamino).