I got these headphones a few months ago, and they are intermittently delivering electrical shocks into my ears while using them. They are lightly used (~2 times/week on cardio machines and freeweights) and had no serious events that could have damaged them. I think it might be related to certain frequencies, but I'm not sure, and there are some posts of other with similar compaints about this line of headphones giving them shocks from static. Whatever the source, it is very unpleasant and I have stopped using this product. I am very disappointed.