LITERATUR UND LINKS
Recommended sites to see:
https://hearinglosscure.stanford.edu/ - advanced research aiming restoring hearing
https://www.spreadthesign.com/ - sign language dictionary
http://www.fundacja-echo.pl/ - Fundacja Echo
http://www.medel.com/ - MEDEL cochlear implants manufacturer
http://whc.ifps.org.pl/ - World Hearing Center clinic