Air conditioners, make lot of noise, specially one that’s are not serviced well & are old. Many homes have Room air conditioner & it makes continuous sound. After a while you don’t realise that constant noise.
With offices this problem is not much, because most big offices have central ducts with chiller units on the roof.
If your Window AC makes noise, its time to call Mechanic or an AC repair guy and fix it. Air conditioning noise is not a problem. It is a very steady straight noise, a low frequency sort of humming noise. It is typically not disturbing unless there is some rattling or clanking noise. What is normally disturbing is the high frequency noise.
When we talk about complexity of acoustics another big thing you have to think about is frequency & psycho acoustics. Which simply means – the perception of sound. Like how does that sound affect you in your mind because that is the most important thing. That depends on the background noise and the nature of the disturbing intruding noise. If you have low frequency steady noise its typically not disturbing. Ac is generally not a big problem unless it is really in bad shape.