How does audio travel through you?

Community General Discussion
1

You are the best people to ask and so I will ask you.

  1. How does an aux cable work? How is sound transmitted over the cable? There doesn't seem to be a (+) and (-), just 1 metal tip

  2. Tested myself If my friend holds an AUX cable plugged into the computer, and I hold one connected to a speaker, and we make contact, the sound plays.

Why are we not too resistive? How come adding more people to the chain seems to not diminish the sound (we had about 6 people in a chain).

I tested again with myself (one cable in each hand) standing on a chair to make sure I wasn't grounded, and it still worked.

2

The "metal tip" will contain gnd and the positive signal.

little notches on the pin usually a black line to indicate where 1 ends, i find it surprising this works...

eg Audio Source > Amplifier > Speaker

So what are you touching? before or after the amplifier stage?

3

I assume the amplifier is build into the computer speakers no? Also if you barely touch the tip of the cable, it still works.

4

I assume the amplifier is build into the computer speakers no?

Yes.

An amplifier has a high input impedance. Therefore when you add the resistance of your body in series with the signal it makes very little difference to the signal because your body resistance is very small compared to the amplifier's input impedance. The body will give about 1 to 30K of resistance to an electrical signal depending on how damp the skin is. An amplifier will have about 1M input impedance so the drop in voltage formed by 30K and 1M in a potential divider is, to use a technical term, sod all.

So it is not audio that is traveling through you but an electrical signal. Electrical signals travel well in salty water and that is mainly what we are all made of.