I’m going off on a tangent here, but… This reminds me of an episode in the novel series The Baroque Cycle by Neal Stephenson. The protagonist, Jack Shaftoe, is near deaf on one ear. During the comings and goings of a military field campaign somewhere on the British Isles where Jack is participating as a soldier, he has a massive plug of ear wax removed from his ear. To his amazement, his hearing is restored, and his previously near deaf ear now provides him with highly acute hearing.
If you like the style of Neal Stephenson, The Baroque Cycle is a good read, although massive.