My mother-in-law told me that when my husband was an infant any loud noise upset him. He would even startle in the crib when someone folded a newspaper.
He's nearly 81 and was diagnosed with Alzheimer's five years ago. He has a good disposition and is appreciative. Loud noises throw him and he's not able to identify them. Lawn mowers, construction equipment, power washers, a pot clanging in the kitchen, all cause for alarm. Everytime there's a noise like that he cries out, "What's that?" and I have to answer. It does get tiring after a while, but I always tell myself it could be worse.
He hates the rain too, like it's his personal enemy. Everytime it rains I have to listen to "Look at that gd rain!" Good luck with that. We live in one of the rainiest places in the US!