Gourami Damaged Labyrinth?

When my blue gourami gets air the bubbles go through his gills. None of my other gouramis or betta have this. Is his labyrinth damaged?

 

I've seen my bettas go up to get air and they sometimes have air bubbles that come out their gills. I think it's normal.

 

This gourami always has bubbles every time. Is that normal?

 

My betta always always has a couple bubbles go through his gills, I figured he was just really gulpin'

 

When a labyrinth breather takes in air at the surface, it goes into the organ, but it forces out the used air from the last breath. Remember, oxygen is only about 20% of atmospheric air, so once they use up that, the rest is left over and has to be expelled. So the bubbles coming out are the previous breath being eliminated.