This is an explanation of my aid. My benefit, which I will call volume in the dead ear, is small overall. But the amount of TransEar (bone conduction) input in my dead side is enough to accomplish hearing in the bone. Add that hearing to the good cochlea and I get a satisfactory summation, a total of better hearing, and sound recognition from both ears. The sound is real, not mechanical nor tinny.
With TransEar the task is to establish
enough bone contact with the mold end to get a benefit. So when I read posts that say "I need to push on the mold to hear something" I think they are on the right track to becoming satisfied.
If I plug the good ear completely, I have enough volume to hear in a quiet setting with the TransEar. But in a noisy room, plugging the good ear again, I get background competition for comprehension. So my TransEar depends on one good hearing ear, and good bone contact.
I do have a vibration sensation in my TransEar when it is picking up sound on the dead side. I am still working on relating the vibration to direction. At least I've told my brain to get busy on it.
Perhaps Cros users (air conduction aids on both ears) will give some details on this topic.