Can you help me with this ringing noise

Every time i record into audacity I get this ringing noise:

I’ve never had this problem before. I’ve messed with the preferences and nothing changed.
Just tell me where it’s coming from and how to fix it.

It’s too quick. I can’t get enough out of it to tell what’s going on.

From the shape of the waves, I’d say something was oscillating. Something’s input and output are connected together like what happens in a band when somebody gets the mic too close to the speaker. Computer systems are typically too slow to scream, but they do rumble and the waves look like that when they do.