Since April 2020 I have been recording The Daily Lectionary podcast which usually consists of 7 readings from the Christian Bible. One of the things that I’ve had to contend with is what to do when I make mistakes.
This is something that every podcaster (or, at least, every podcast editor) needs to figure out, even if your podcast doesn’t require you to read the entire genealogy of Jesus. Some people make notes of timestamps, other people make some sort of audio cue, such as snapping their fingers.
I wanted something very simple (a single clap) but I also didn’t want to have to clap my hands loudly every time I made a mistake, if for no other reason than my wife is sometimes asleep in the next room.
I decided to make my computer do it for me – more specifically, my Stream Deck, which has the ability to play a specific audio file at the push of a button using the “Soundboard” action labeled “Play Sound”.

(Aside: Although I am using a Stream Deck, you could also do something similar with Farrago or even Keyboard Maestro, etc. using the same method described here.)
After recording myself making a single loud clap, I saved the file to my computer, and then added a button in an easy-to-reach location on the Stream Deck. Its action looks like this:

The next part is actually my favorite part. In Audio Hijack (which I use to record my audio), I added a block to send the output of the Stream Deck directly to the .wav file that I am recording. This means that I don’t have to hear the very loud clap in my headphones, but it will be added to the audio file.
This seems like it would also work well if you are recording a podcast with several people, because if you need to mark a section for editing, you can use this method without deafening your co-hosts and/or guests.
The result is a very clear, stark indicator in the waveform that shows where the mistakes were. Here’s an example of one of the few times that I only made one mistake:

This makes it very easy to spot the mistakes for targeted editing. I hope this helps someone else. You can download my clap mp3 here.