My ears don't hurt, but my left ear feels a little blocked afterwards. I was standing a meter and a half away from a machine that fits rim into the tire, while also pumping air or something. The tire was lying horizontal. Anyway it popped loudly like a gunshot. Is this normal sound? I didn't like having my ear blocked. Is this permanent damage to my ear? I didn't have my ear right close to the tire but I was standing close. Is this normal when fitting new tires?
This is absolutely normal. What's going on is they are seating the beads of the tire against the rims. In order to get them to do this, they have to over pressurize the tires a bit, which then allows the beads to pop over the sides and seat hard against the rims. This ensures they are in position correctly on the rim and promotes sealing after the fact.