Good luck with that. We took our oldest on his first flight when he was about 6 months old. Turned out he has an extremely rare genetic condition (like 1 in 10 million) where hearing levels can fluctuate and head trauma or pressure changes (or a couple of other things including just totally random time) can cause complete permanent deafness. Departing flight was fine. Return flight - up we went, down we went - pop - he never heard naturally again. 3+ years, learning sign language, genetic testing, $200,000 of bilateral cochlear implant surgeries on an infant/toddler, and a ton of hearing and speech therapy later, and he is on a normal school track. Fun times. Thanks, US Air (just kidding, not their fault).