I’m sure we are all familiar with ear fatigue, volume spikes etc, I have been knee deep in synths for 2 years and thought I found my groove for avoiding hearing discomfort. I have noticed some funky sound cancellation phenomenon turning my head and whilst playing the Super Gemini. More worrisome a heightened level of ear ringing and fatigue than usual or at least that I perceive. I started to wonder is there a reason the patches are so quiet, is UDO worried about the output? Can binaural sound reinforce/cancel frequencies that lead to more potential for hearing damage. I don’t want to troll or be alarmist, I want to love this synth and I am generally curious if any one has better data or knowledge on the first principles, I admit I don’t have the background or equipment to test the supposition.
I can say that I personally find my Gemini quite soothing and comfortable to listen to, both through headphones and monitors, though I’ve spent more time in headphones as only got monitors recently. I can also say it has been a concern for me, as I’m in my 40s now and tinnutus is something I started really noticing a few years ago - it can be quite bothersome. My feeling has mostly been one of relief and deep enjoyment listening to the synth, it is much less fatiguing to my ears than anything else I have. I don’t know, but I think having plenty of headroom and dynamic range helps with this, as well as the complex and involving sounds it is capable of. I guess the patches are quiet because they’ve standardised them all on the cautious side, I doubt it’s due to worry about causing hearing damage, as that would largely depend on the listening habits of the user. I have a nice pair of open-backed headphones, by the way, which I think might also help with comfortable listening - they feel loads better than the closed noise cancelling pair that I also have.
(When using binaural beats technology to entrain brainwaves to certain frequencies one might prefer to be cautious, as some of the brain states involved can be deep and trance-like, “not suitable for listening to while operating heavy machinery” kinda thing - but “binaural beats” is something quite different, it is not the same sense in which the UDO synths are said to be binaural.)
(Also, one of the things I try to do when my tinnitus is bothering me, say laying in bed awake in the dead of night, is to consciously relax my jaw - I find it helps. Also I can listen to different parts of the sound, and sometimes if I listen just right it dips right out, like the sound of a river you’re no longer paying attention to. Weird. It got really bad for me at one point, such that I was feeling a little shut in by it, but at some point something just shifted, somehow, and it has been bothering me much less since, though it is still present. It’s a difficult area, being a sound only you can hear! It seems definitely a good idea to avoid sustained periods listening to sounds at high volumes (or raving right in front of the speakers, or sticking your head in the bass bin 
) but as I say: playing my Gemini has felt good for me in this respect, more than anything.)