I'm thinking about wall mounting a television, so I've used a stud finder to locate several studs in my wall. Out of curiosity, I knocked on the wall in several places to see if I could hear the difference between hollow and studded areas. To my surprise, when knocking directly over the studs, there seems to be a metallic ringing sound.
Is it actually possible to hear this with a steel stud, or am I deluding myself? The wall in question is plaster, if it matters.