Chen, you know I fully appreciate your desire to learn and experience; as a matter of fact I even share it! However, all of the examples you give, with a few very rare exceptions, only cause temporary damage that repairs itself and has no real long-term side effect or damage. I have been tazed, maced, and toughened myself for martial arts training, but I had no damage beyond a few days or so. However, after studying a little about hearing, I had two sets of custom earplugs made to fit my ear canal that will cut a LOT of noise and they each came with a small pocket carrying case. Damage to the ear is so easy and so permanent, as well as having constant side-effects like Tinnitus, that I not only carry the ear plugs for shooting, but every day for loud situations like screaming children in a restaurant or a loud repair shop or factory. If I had the chance, I might try to get them in during a shooting! The ear is about the only part of our body that seems to be less forgiving to abuse and does not heal itself as well as most of the rest of us.
When I was younger I shot firearms intermittently without hearing protection (we're all impervious then, ya'know?), then I had a 12-guage shotgun discharged near my face that left me with severe tinnitus for a week and about a year later a large blast went off before I was behind cover, leaving me with a minor concussion and a bleeding ear. I decided that was the end of my hearing stupidity! This is an interesting discussion because I had a hearing test yesterday and the doc told me my hearing was much better than he expected it to be for someone my age. I believe those ear plugs have really helped me save my hearing as I reach middle age, and should I ever have to defend myself and possibly deal with auditory exclusion I will, but when I was younger, I do remember my ears closing to the point that people behind and to the side of me became harder or even unable to be heard - THAT was what originally started to worry me!