When to take bera for newborn. Month?.

Now my son is 2.1 months. First and second oae at 5th day and 20th day came both refer and 21st day we took bera.. it showed profound hearling loss. One more info, he had jaundice on the 5th day with 16.5 value, and his birth weight was 2.25 and when he was discharged after jaundice, he was only 2kg. Ent suggested to take bera after 3 months. I see some response in him after 1 month like any sharp sound he startled a few times.. and while he is sleeping, any normal sounds.. his breathing pattern is changes.. when we engage him(no hand movements) through talking.. his attention is completely on us. If some new people come home and he is sleeping.. all the chit chats wake him. Even for the feeding cycle, if he is asleep, we wake him up by calling his name and giving sounds.. he flings and moves.. recently, he started cooing. For rattle sounds.. he is not turning for the sound(may be i m over expecting). should I wait for the 3rd month to end or wait for another one month??.