"hear" is not used in the continuous tenses that often in English.
"I can't believe what I'm hearing" sounds fine to me, but "You are hearing well" sounds wrong to me.
In English it is atypical to use adverbs to modify passive verbs with adverbs without the word can. So the answer to "How well do you hear?" is usually "I can(not) hear well." Note the exceptional case of "I am well," though some people will tell you that in this case well is actually a weak adjective because the use of adverbs in that way is so rare.