Default [Q] Ear piece problem after water test

Unfortunately I same as many others couldn't help to test my ZR's water resistance. First sound from both speaker and earpiece were muffled and given the water penetration it seemed ok. After a while speaker got back to normal but the sound of earpiece is really low. Before water test it was really loud and even from 30cm distance you could hear other party quite clearly but now even enabling hearing aids is not enough! any hints of solving it?

it's been 2 weeks since water test.