@Override
 public void setVolume(float v) {
   if (use_start_sound) {
     start_sound.setVolume(v);
   }
   if (use_mid_sound) {
     mid_sound.setVolume(v);
   }
   if (use_end_sound) {
     end_sound.setVolume(v);
   }
   if (use_short_sound) {
     short_sound.setVolume(v);
   }
 }