Play 3D sound using say3D on a static object. Place player nearby. Switch to splendid camera - change time acceleration. Sound occasionally is very loud irrespective of whether player is in 1st or 3rd person. Seems easier to reproduce by changing focus - Alt Tab - to desktop and then Alt Tab into Arma3. Sound sometimes is much louder than before - it then either stays at that higher volume or starts to gradually attenuate. As if it's lost focus on the object playing the sound and its relative distance to the player object and related volume.