Ear Growth

You point at a creature you can see within range, which must make a Constitution saving throw. On a failed save, the creature grows sensitive ears all over its body for the duration. In this state, the creature has advantage on Wisdom (perception) checks requiring hearing and has vulnerability to thunder damage. Whenever the creature takes thunder damage while in this state, it must succeed on a Constitution saving throw or fall prone and become deafened until the end of its next turn.

If the target had no natural sense of hearing before the spell was cast on it, the ears it grows grant it a sense of hearing for the duration.