Maybe preload sounds. The code from Scene.SoundPlay method:
public SoundVirtualChannel SoundPlay( Sound sound, Vector3 position, double priority = 0.5, double volume = 1.0, bool loop = false )
{
var mode = SoundModes.Mode3D;
if( loop )
mode |= SoundModes.Loop;
var sound2 = sound?.Result?.LoadSoundByMode( mode );
//
//
// if( sound2 != null )
// return SoundPlay( sound2, position, priority, volume );
//
//
return null;
}