Not a dumb question! Many technicians wear earplugs while tuning to cut out helpful noises, but also to reduce strain on their hearing. The percussive sound of tuning causes aural fatigue, and the right pair of earplugs will enable you to hear the important things without becoming fatigued by excessive sounds.
So (dumb question here) do you wear them while tuning (in case noises from outdoors might affect your hearing)?