I bought this product about 5 years ago and it works great. It's in the basement and is loud enough to hear anywhere on the first floor and in some locations on the second floor.So why the negative review? I bought another in December 2010. It looks identical to the first one but the alarm now sounds like the faint chirping of a cricket. Tried different batteries, same result. OK, well the first one is still working well, I asked Amazon for a replacement. Free return shipping, fast turn around time. I love Amazon. However, replacement alarm has exactly the same problem. You would not be able to hear this thing across a medium sized room unless it was the dead of the night. I don't know what happened to the quality control at Sonin, but I recommend that you look elsewhere. It's more than likely that you'll be sending yours back as well.