I'm answering from the dark side, where I live in the worst of both worlds. I need hearing aids for conversation, and even then I sometimes just don't get female voices, and... I have to stuff my ears with cotton wool for concerts. Quiet sounds I can't hear; loud sounds hurt. Some of that is rubbish, and some of it is completely true. The idea that you should buy expensive audio, because, hey, your ears-brain adjust and it's still worth it, is... moot. Sometimes yes. Sometimes no. I would emphatically say, do not buy bad audio, because it will annoy the hell out of you much more than it might have done in better-hearing days! Weird. But true. The ear adjustment thing, as per that video, is over-exaggerated. If he had, say, High-frequency hearing loss, which is the common thing from ageing/loudness, let him try to compensate and hear conversation properly. No, you can't. First, someone takes away the differences between P, B, D, T, then the softer consonants meld into that mush, then you are earin omeiin wih ha liile meaning at all and then you don't even know someone is speaking to you. This is what happens to conversation: does he think music fares any better? No, it does not. But music contains so many frequencies and their harmonics, and we have memory, and we can continue to make something of it. Details are lost, and do not get compensated back in. Air is but a dream: never to be heard again. I can still hear a violin and know it is a violin. I can enjoy the melody I am hearing. I'm not aware of what I'm not hearing because, yep, I can't hear it. Hearing aids give me an idea of the shimmering highs in the violin tone, but do they improve music? No: mostly they make it sound like cheap horrible audio! My hearing, at last test, slopes off from one kH. I haven't got one to try, but not sure whether I can even hear the top few notes on a piano any longer. I can't hear the beeps that idiot young designers build into gadgets, so can I hear every not a piccolo can play? Probably not. Can hifi help? I decided a while back that it was no longer worth spending money on my ears (I switched to photography so I'm no richer!) and then... I discovered the difference that HD800s make, even to the spoken word: a great investment! And there are surprising things, like finding that I can tell the difference between two amplifiers on the same 'phones. And, as I said, that bad sound is not only still bad, it is worse. I get out a lot to (sadly often over-amplified) South-Indian classical music. I love the whole experience. And I still hear a lot of the sound. More than you might think. But I don't listen to much music of any kind at home, any longer. I find it a bit like listening to low-bit-rate MP3. I don't mean 128: I mean 32. The life goes out of it. Is it worth buying high-end audio when you are already getting actually deaf? No. It isn't. But avoid bad audio like the plague. The question can you hear the difference becomes very literal. Hell, yes, sometimes its the difference between bearable and intolerable. And don't be afraid of EQ. The music that comes as close as I can tell to balanced would be someone else's screech. In that respect, high fidelity is certainly a thing of the past.