I use this cable to connect my iPhone to my sound system. If I have not connected the iPhone, booming sound system; when I connected it, the hum is no longer there. Another cable, which I happened to have found this hum had not. As the hum only occurs when the cable is NOT connected to the iPhone, which is not so tragic, for me personally, however, a problem, which is why I now but the other (randomly found) cable use.