Speakers and Static from Hands Why is it that when you touch the a bare male end of a speaker feed that the speaker makes hissing noises? Is it just (eddy?) currents running through you?
 A: First off, what you describe only happens for highly amplified speakers.  The current change when you touch the wires is pretty tiny and you'll only hear a sound when that signal is being amplified significantly before being sent to the speakers.
There are many reasons why a tiny bit of electric current flows from your body to the speaker wire so I'll only list a few off the top of my head:


*

*When you first touch the wire any static electricity can flow to the wire which could make a loud pop

*Air moving over your body provides a constant source of static electrons which can flow into the wire

*Sweat and salt can act as a tiny saltwater battery between your fingers and the wires

*Your body produces tiny amounts of electrical current (this is how your neurons work)

*Your body can act as a giant inductor for the $50$ or $60$ $\mathrm{Hz}$ electric current from the power grid (and therefore changing magnetic field) surrounding you

*Your body is a (poor) antenna for the radio waves passing through you

*The "ground" your body is making contact with may have a tiny varying potential which would allow current to flow from the wire through your body to this ground (and vice-versa)

*The speaker wire is typically two wires right next to each other that act as an antenna.  if you touch only one of the wires you act as a ground allowing induced current from radio waves to flow through you to the ground


Without a lot of experimentation it's hard to know which of these are the significant sources of electric noise and of course, there may be others I didn't list.
