Tinnitus is very common. Like sensorineural hearing loss, it is often caused by exposure to excess noise. That noise can be something immediate, like an explosion or something that has been present in your life for a long time like working in an environment with a lot of constant background noise. Loud music is often a cause. So is hunting, serving in a military combat zone, etc. This is why ear protectors are so important.

Reality is...it often will change in 'tone' or soften over time, but once you have it, it's probably going to stay. The best remedy is to try to screen it out with other thoughts and sounds. The brain can do remarkable things with appropriate stress management techniques. I have had it since I was in high school. Not sure why, but I hunted with my dad a lot, and also enjoyed music. I was diagnosed with sensorineural hearing loss in my 20s. That has gotten worse over many years. I wore hearing aids from my mid 30s on, and now have a cochlear implant in one ear. Those technologies have kept me in the hearing mainstream.

Do get a baseline hearing test. You may not have a measurable degree of HL, which is a good thing, but know it's wise to use ear protection in noisy settings. You describe your possible 'tinnitus' as rather soft sounds, so I hope it stays that way.

Keep us posted on what you find out. Lots of research is being done on hearing, tinnitus, etc,, but it's coming rather slowly.