Headphones 1.8: What are headphones, actually?

Requirements of a sound machine:

If you wanted to make a machine that can produce to make every possible sound, it would need to be able to able to vibrate at any speed. 

In order to be able to make all sound that human can hear, the machine would need to… at a frequency of up to 40,000 “on’s” and “off”s”

What is a solenoid?

They consist of an electromagnet ( a coil of a wire that electricity can flow through) and a permanent magnet. When you phone sends an electric signal to your headphone, the electromagnet acts like a magnet and attracts or repels the permanent magnet. This machine simply pushes a rod back and forth when you applied electricity.

Making a solenoid vibrate

If you repeatedly turned a solenoid on and off quickly, it would make sounds, the faster you turned it on and off, the higher the pitch is and eventually you can’t hear it anymore because the vibration is too fast. When your phone plays music, your phone converts those “on’s” and “off’s” into an electrical signal into the audio jack.

What are headphones?

A solenoid that converts on and off into music.