The exit row requirements for US airlines are listed in 14 CFR 121.585.

https://www.law.cornell.edu/cfr/text/14/121.585

(b) No certificate holder may seat a person in a seat affected by this section if ...
...
(3) The person lacks the ability to read and understand instructions required by this section and related to emergency evacuation provided by the certificate holder in printed or graphic form or the ability to understand oral crew commands.
...(5) The person lacks sufficient aural capacity to hear and understand instructions shouted by flight attendants, without assistance beyond a hearing aid;

(6) The person lacks the ability adequately to impart information orally to other passengers;