How do headphones/Speakers (audiot output devices) work?

Question

Ive always wondered this, and im sure i could look it up, but its easier having it explained. I no like music boxes and records work by plucking shards of metal or grooves on a record in precise sequences to produce minute sound that together produce tunes. But with todays speakers and headphones, What is it inside thats Actually creating the sound of human voices and music, and etc. What contact or actuall physical things is producing the sounds? Im sure once i learn it it will seem very clear how it works. But still its just amazing thinking we started as monkeys on a planet, and have used this planet to make things that can do what some of the things today can do. a testament to our ingenuity. but I still think we could be alot farther than we are. sigh.

Answer 1

the basic concept of a speaker (including a tiny speaker in headphones) is that a coil of wire is next to a permanent magnet. when the apmplifier sends current through the speaker wire it causes a magnetic field to be generated in the coil. that magnetic field interacts with the field of the permanent magnet either pushing it away or pulling it close. this coil is attached to the cone you see.
The amplifier changes the current in the coil in the way necessary to vibrate the coil/ cone exactly as sound. and so you hear it.
a fun experiment is to take a AA battery and put it across the speaker leads. If you have positive to positive the cone will push out of the speaker box, towards you. Flip the battery around and it goes back.