unhear means to reverse the process of hearing, so that (a sound, etc.) was never heard. Lexicurio rates it Sui generis — a strength score of 89 out of 100.
Etymology
From un- + hear.
verb
- To reverse the process of hearing, so that (a sound, etc.) was never heard.“I wish I could unhear that terrible song!”
- To forget a sound.“They could never unhear what they heard that night.”