This slot is used by Heretic's SoundSequence actors and gives them common properties.
Contrarily to the ambient sound things SoundWaterfall and SoundWind, these sound sequences are not positioned in a given place in the world: they are played at the same volume everywhere in the map and do not seem to originate from any point. Only one sound sequence will be played at a time, randomly chosen from all the available (and active) sound sequence things placed in the map. Placing several identical sound sequence things allow to weigh the odds of this sequence being chosen: for example, if three "bells" and a single "laughter" sound sequences are placed in a map, the bell sound will be chosen about 75% of the time.
:HereticAmbience // Heretic waits 10 seconds after level load before it starts // playing any sounds. delayonce 350 volumerand 0 50 attenuation none randomsequence delayrand 210 465 restart end