Some skin wonderings

Do all people have a crease an inch and a half from their inner elbow as they begin to bend the elbow?
Do all people hear through their skin when they rub skin close to their ears--or as far away as upper arms? It sounds like I don't just hear it externally but that I also hear the vibrations or something. I assume others can't hear my skin that way...

Hooray for reawakened wonder. Thank you Dr. Nelson.