My mom had a bad case of COVID (13 days in the ICU). It affected her hearing. She said the hearing in her left ear would just cut out almost completely, and then later come back but not as strong as before. She went for a hearing test and they verified she had some hearing loss. She also experienced a number of other side effects but she's thankfully mostly back to normal now. You may have dodged a bullet by getting the vaccine, but like you said there's really no way to know.