Not sure about European regulations: in the US the hearing “test” is if you can understand a normal conversation when the examiner is 6’ away and facing away from you. If you can pass this, you’re good. If you can’t, then the next step is a more in-depth audio test.
When I get my exam I wear my aid, although I can probably pass without it. So my restriction on my medical says something like “hearing amplification required”. Most pilots will say, “as long as I am wearing a headset with the volume turned up, that meets the definition”, so some will remove their aids when flying.
Again, I don’t know the European rules, but in the US there are plenty of deaf pilots. Radios aren’t required unless you’re in a controlled airspace that does require two-way radio communication. Even then, it’s probably possible as long as you have a second pilot.
Easiest way to know for sure is to contact your aviation examiner ahead of time for a consultation. Maybe even get the hearing portion of your test done. In the US you really want to make sure you will pass before you start the exam, there are too many consequences if you fail.