Why is there a buzzing sounds coming from my PC audio out jack?

Sounds like a dirty or dammaged connector.

There are a couple of possibilities.

It is possible the headphones are broken or defective, like blown speakers; the sound coming out of the computer is OK, but the headphones can’t reproduce it for some reason.

More likely, the connection where the headphone plug goes into the connector at the computer is faulty. As @ChazMaz said, a dirty or poor connection there can cause awful static.

Clean the male part of the plug from the headphones with some rubbing alcohol on a soft cloth. Dry thoroughly.

If there is still a bit of static after cleaning, plug in the connector and twist it back and forth to help clean the connection inside.

@PerryDolia I have tried with multiple sets of speaker and headphones, and they all get the same result, so I’m sure it’s the PC that has an issue.

I have had like problems… turned out to be tired ¼ inch jacks.