Owning a condo can be worse than renting an apartment with bad neighbors because it is not so easy to give a 30-day notice to move out when you your next door neighbor cannot sleep unless he is playing his thumping music that vibrates your walls all night while you are trying to sleep.

It may hurt at first to spend less time with a friend but their vibration will zap your positive vibration.

first of all the big hunkers can vibrate the wall especially when turning off or on.Secondly when they fail and ultimately they will fail, you can't get another unit to fit the hole exactly and need to reduce or expand the hole through the wall.And thirdly they're not usually tightly sealed in the winter.When those type units fail we remove and patch the hole inside and outside.

Also, some appliances vibrate more than others.

Noise that is not transmitted through vibration is just sound waves traveling through empty air.

I plan on replacing with tile.I have tried a 5 inch scraper with a 4 foot handle, then I tried the same scraper and a 3 lb sledge, then I tried a hand held vibrating scraper you buy at Harbor Freight. 

It vibrates back and forth and you push it.

A personal visit develops a much better vibration with the seller.Frank

Noise comes from vibration, vibration comes from excess energy being channeled incorrectly.Be prepared to rewire the house.

To succeed in life you need to be on the same vibration with you significant other.