Very interesting to read all the comments. I think spending money on a quality sound pressure meter with a calibration device makes sense and very worthwhile. Reed Instruments seems good.
Surprised no one has discussed keeping their ears clean. I had some blockage a couple years ago and I applied sweet oil daily for a while and that softened things up and got rid of the problem. When you chew food the movement tends to be a self cleansing mechanism for the ear canal area. Also flowing warm water from a shower to the ear area is helpful.
Also I take metoprolol, a heart medication, and side effects are tinitus.