system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do my computer speakers produce noise when the plug in touches my skin?

And also, why don't my headphones do the same?
gpt
Your skin has a small electrical charge on it. You can check it out by holding the end of a voltmeter or touching the input to an oscilloscope. This is basically seen as noise on the line since your body is not grounded and comes out as a noisy sound from the speaker. If you also touch the ground of the plug with the same finger, you will notice the sounds goes away.

Since computer speakers are powered and headphones are not, the noise can be amplified loud enough to hear. Headphones rely on the power of the signal to produce sound. Your skin does not produce enough power for you to hear the noise.