[Jazmanaut]

Very interesting. I did not know, that eardrum works in both ways. But offcourse, what goes in one direction, must come back as well.
https://eu.nuraphone.com/pages/how-it-works

 

[Jazmanaut]

Every day, somethin new.
https://en.m.wikipedia.org/wiki/Otoacoustic_emission

 

[castleofargh]

Very interesting. I did not know, that eardrum works in both ways. But offcourse, what goes in one direction, must come back as well.
https://eu.nuraphone.com/pages/how-it-works

^_^. it's not the eardrum sending back the signal, just the shape of the ear sending back reflected signal and giving a few cues about the general shape of said ear. while there is a solid interest in those stuff recently and I'm very glad for it, not everybody agrees on what works or what is necessary.
the AKG N90Q does something a little similar, by calibrating itself once on the user's head.
anything aiming at a more individual customization is in the long run a good thing, because that's where we must go anyway if we really wish to make headphones the best listening source.