I don’t know what you mean by descriptive link or what the show is.
I think you hit everything. I went down the Google Pathway to find out what a Snap was. You said you were narrating audiobooks. That’s your show.
Unless a failure is common and wide-spread, we have to build your studio in our imagination to solve problems. It’s nice to think we can just pull solutions out of thin air, but it doesn’t work that way.
I didn’t change anything before the hiss started happening.
…that you know of. Do you let your Mac do Auto Updates? It’s internet connected, right? I make my Mac notify me of updates and then do them when I’m at a good stopping point. If there is a possibility of danger, disconnect the internet, finish my job, reconnect, and do the update.
Nothing springs to mind immediately. Will you produce a ten-second sound test?
https://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html
Some noises have signatures and we can tear them apart and identify them and sort what’s causing them. For one example, noises whose pitch clusters around 60Hz (in the US) might be traced to room wall power problems.
In your specific instance, a hiss sound is always produced by microphone systems. The goal is to make your performance so much louder that it doesn’t matter. 60dB (in English) is a thousand to one. Make your voice a thousand times louder than the hiss.
However, Macbooks do make very quiet noise and it’s possible to position a Mac such that its vents are pointed to the AT 2020 USB Plus which is a directional microphone.
And that’s why it’s good to know all about your studio. Is it possible to temporarily move your Macbook further away from the 2020 and see if the noises change?
Debby Downer wants to suggest that you could have a broken microphone. That’s another reason for us to analyze that brief sound test. You are correct. You should not suddenly need to use Noise Reduction.
Koz