As a hearing loss elder, I wish I had known then what I have since learned. Between a mis spent youth running around in loud cars and a military experience involving loud noises and a pleasurable but noisy hobby, some how I find that I need very expensive hearing assistance just to do ordinary things like talk to friends and family, watch television, go shopping and have appointments and meetings. What has happened in my case is cumulative rather than sudden, consequently I didn't realize what was happening until it did. What has happened to me is basically operator error. I didn't notice it happening and you may not notice it either but it does!
http://www.woodworkingtips.com/etips/etip43.htmlIf you are interested in the really technical stuff,
https://www.osha.gov/dts/osta/otm/new_noise/