https://www.reddit.com/r/thinkpad/comments/k6fu6y/hey_i_have...
I had some fun with this one, as mentioned in my comment there. I downloaded Lenovo's app and had it listen to the audio in the post, and it told me the error code and recommended steps.
I guess I am easily entertained.
Many BIOSes used a sequence of beeps to convey the error code. Here's a page about this (found via googling for 2 seconds, so standard caveats apply): https://www.computerhope.com/beep.htm
For the new Lenovo beeps, the idea wasn't that you would listen to them and look it up in a doc like you would with the old PC beeps. They were intended for people who would call customer support and say "my computer won't boot and it makes these strange sounds!"
The CS rep would run the app while on the phone call, have the customer reboot, then the app would listen to the call, hear the beeps and display the error code and recommendations.