I use timers that turn off equipment. I cannot hear a simple timer chime, buzz or make noise below about 130 DB. Smoke detectors also do not fall into my hearing range. Good thing the wife has real good hearing. I had hoped this system had a pressure relief valve type setup and did not require my personal attention. I know this sounds picky but I also have a condition I call focus attention disorder. If I am focused on something, everything else is out of the picture. When working on the computer or some project, I will not hear people talking to me or side noises. Great condition for work, not so good for conversations and social activities.