Also make sure Audacity is the only program running. Close all your known applications and restart the machine.
In extreme, disconnect your network. If you do, pay attention to error messages complaining about disconnecting your network.
There’s a list of computer-y things that can interfere with live, ordinary voice recording. That’s why I recommend not recording on the computer. Stand-alone sound recorders and even your phone can do a very nice job.
If you use your phone, make sure your iPhone Voice Memo (for example) is set for “LossLess” quality and you can transfer the work to your computer for editing.
Other phones may have other settings.
I recorded that on an iPhone in my quiet, echo-free office. I mastered it and it passes audiobook quality tests.
Koz