I always wonder if hearing aid has military applications, or for non-hearing-disabled people. Is it possible to have an above average hearing with this?
I warn against using devices to make it easier to hear - when you have no hearing loss - as it could make your hearing system "lazy".
Just like physiotherapists now advise against overuse of knee and neck braces. Better to strengthen the muscles needed to do the function rather than supplement with an aid.
One of the biggest advantages of German tanks in WWII, was the excellent communications system. It was engineered so that all members of the crew could clearly hear instructions in battlefield conditions.
Technology which can improve communication and perception and also protect hearing in battlefield conditions always has military applications.
Is it possible to have an above average hearing with this?
You can already buy consumer electronic hearing protection devices which can allow you to hear quieter sounds than otherwise, while protecting you from loud transients.