I recently had my hearing tested. One of the tests had the earphones placed on my skull above and forward of one ear and below and behind the other and it was amazing how well I could hear the test tones.
What wasn't amazing, but rather depressing, was what I couldn't hear. 😩
There's so much reinforcement going on with more than our ears than we appreciate. Factor our brain into it and you'll find that it is
highly nonlinear when deciphering sound. Test equipment, on the other hand is very linear in measuring sound. Or, used to be unless you have the money for some really serious tests.
Hearing aids have always been poor performers in restoring hearing acuity. It's down to what area do you prefer compared to what you can do without. Around the early 90s, some group came up with
nonlinear signal processing to get closer to approximating what it is that we actually hear. I don't know if it actually worked or if it's commercially available.
Based on that, can we finally put to rest the falsehood that what we measure is what we hear, and nothing more?
All the best,
Nonoise