All I will say is this; my sister was raped a couple of years ago and since then she began to carry one around with her. She's since stopped though, so I don't know if she's become more self-confident or whether or not she doesn't recommend them - probably a mixture of both. But they are really heavy to carry around, they are quite chunky and the batteries are a little strange so are relatively difficult to replace. Having said that the noise is indeed very loud and high pitched. To be honest though, I think you are better off saving your money and just being wise about personal safety; ie. don't wear headphones when you are on your own late at night, avoid darkly lit areas, always tell somebody where you are etc...after all, the alarm isn't actually going to prevent you from being attacked in the first instance.