Here in the UK, I was told about the importance of wearing ear plugs on my CBT (125cc primer!).
The instructor told us he had average hearing at best, which is a result of all that bike riding - he says you will experience hearing loss as you get older, if you don't wear plugs (due to the YEARS of bike riding).
I can appreciate this, more so riding at higher speeds (motorways / dual carriageways), where wind noise becomes profound.
I then get off my bike after a (high speed) ride and often ambient sounds are slightly muted for a while, from the riding noise I've just experienced <<< THIS is causing damage!
Seconds to put in, but the benefits can help over a lifetime!