sounds variability + first step fix

src/audio/audio.cpp

@@ -249,6 +249,12 @@ speakerid_t audio::play(
     int priority,
     int channel
 ) {
+    if (!sound->variants.empty()) {
+        size_t index = rand() % (sound->variants.size() + 1);
+        if (index < sound->variants.size()) {
+            sound = sound->variants.at(index).get();
+        }
+    }
     Speaker* speaker = sound->newInstance(priority, channel);
     if (speaker == nullptr) {
         remove_lower_priority_speaker(priority);