system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do audio wires work? How does a unit send something through metal wires that comes out of a speaker as a song/voice/etc?
gpt
Ever shaken a large sheet of paper back and forth and listened to the wobbling sound it makes? It's from the air being pushed back and forth. In other words a very primitive speaker.

Next, take 2 magnets, in one position, the attract each other, in a different position they repel each other. Now what if we can turn one of those magnets on and off? Such as sending current through an bit of coiled wire, and making an electromagnet. Now we can make the magnets repel or attract with out having to turn the magnet around. Now we've got a very primitive voice coil.

If we attach this primitive voice coil to a diaphragm, we can make the voice coil move back and forth, which moves the diaphragm back and forth several hundred - thousand times a second. That movement of the diaphragm moves the air, which transmits those vibrations to our ear, which we hear as sound. 

Put your fingers on your throat, and making a hummm sound, you'll feel those same vibrations. The more complex the range of vibrations, the more complex the sounds.