I have high octane AD[H]D and as my hearing "goes" so does my ability to listen to people with noise around. For at least 12 years i've had to warn my wife and children if they're not facing me when they talk i can't hear them - but i was recently let in on the fact that other people consider them mumblers, so. I have a heard time hearing most people on the phone, especially call centers.
Prior to what i would describe as idiotic practices in my 20s and 30s, i could focus rapt attention on as few or as many people as required in nearly any situation, parties, bars, whatever. Music venues obviously not, but looking at someone and talking loudly near their ear (vice versa) worked fine.
My hearing issues are similar to my FIL's, who is 50% deaf in one ear and 95%+ in the other. if you're sittin on the wrong side, you're getting a lot of smiles and nods, because "eh?" gets old. real. fast. However, i can hear a raccoon messing around outside, and no one else seems to hear it; also a phone notification going off in the next room, as examples. my hearing "feels" fine, except in the very specific circumstance of human speech recognition. I also have tinnitus sometimes - it comes and goes, and if i concentrate i can focus it to the point of wincing, sometimes.
interestingly i have to turn down the master volume of games when i am voice chatting. any amount of noise from the game will interfere with my ability to process people speaking, especially if the game has a lot of talking. Additionally, i cannot watch any tv or film produced after about 2000 or so without subtitles, regardless of how fancy the "5.1 surround" center channel DSP is.
sorry for rambling, i suppose i don't think ADHD has anything to do with my hearing loss or issue; I should have worn hearing protection more when i was younger and i'm not regretting it much now, but when i can't hear music i enjoy i'll be pretty sad about that.