Why am I hearing this cricket-like sound/static through my headphones/speaker when the volume is turned up?

I am currently using external headphones with my mac, and somehow, this static-like sound (reminds me of crickets starts to be heard even if the volume is only turned up a quarter of the way. Why is this happening? This has never happened before. I've tested it with both MacBook Pro speakers and my headphones, and the same issue occurs. This is a really annoying issue, and I would like to get it resolved.