Beeping?

I have owned my Macbook for years and have only had issues with it once a few years ago.

A few minutes ago while working on my Macbook, a beeping noise started. It was a constant beeping that happened every couple of seconds and lasted until I rebooted my computer. My computer was also frozen for some weird reason.

I had my earbuds plugged in so I could hear the beeping really clearly but when I removed my earbuds, the beeping stopped.

When I rebooted the computer, everything seems to be working fine now.

What would cause this?

Has this happened to anyone else?

I searched on YouTube but none matched what happened to me. Some were only three beeps while others were longer.