There are some things that simply make a ton of noise when they’re running.
I had a vacuum for a few years that my neighbors would complain about.
The thing is, I live in a house; so that means it’s so loud they’re hearing it through my wall and into their window. To top it off, our houses are at least 20 yards apart. I think the vacuum alone was starting to give me tinnitus. I’m also used to having a loud washer that sometimes makes banging noises when the load of laundry is spinning out. Although I should probably replace it soon, it’s hard to bring myself to spend the money when it still technically works. However, there are some things that should be looked at immediately once you start hearing loud noises during operation. A car engine is a good example, but sometimes it’s not so obvious. HVAC condensers are the outdoor components of standard split style air conditioners. They’re supposed to make noise while they run, but they shouldn’t sound like an old refrigerator compressor while they run. Since they have the same kind of compressors just larger, hearing these old refrigerator sounds will give you an indication that you need your condenser inspected. My HVAC supplier had to install a new compressor after the original started to get really loud every time my entire air conditioner turned on. I was lucky that it was covered under the manufacturer warranty because it happened within the first 10 years of ownership. My neighbor has the same exact problem, but his HVAC supplier is refusing to fix it. I tell him that it gets louder every week and he just nods his head in agreement.