Has anyone ever had an hearing test done by an audiologist, and then used an equalizer to adjust their speakers to compensate for measured hearing loss? If so, what did you notice? I suspect that for older audiophiles, or those among us who have listed to too much loud music, there are people with significant hearing loss over 1000 Hz; even a loss of as much as 40 dB is considered "mild hearing loss" by audiologists, but imagine how that much affect the evaluation of audio components. Here are some samples of normal and pathological audiograms:
http://www.audiologyawareness.com/hhelp/agramdem.htm