I suspect that it's much easier to hear the audible pattern than to see the pattern of a blinking light.

the frequency range of pulsing audio is much higher than pulsing light thats for sure. sound was used a lot to calibrate analytical instruments in labs. throw a frequency divider a tiny amp and a tiny speaker and you could easily find if your frequency is stable, drifting...

Sure, I wasn't suggesting it was an improvement. I also assumed the actual pattern isn't important in a strict sense, just as an indication of when and frequency?

But of course, in general either could be the case. And perhaps don't want to wear earphones (or disturb colleagues) etc. only meant it as an additional similar idea.

Waterfall display might work though, or coloured sequences give each function it’s own colour then draw the last stack as a pattern of colours, humans are really good at spotting anomalies in patterns, probably because tree,tree,tree,wolf,tree was useful to our ancestors.

This was common in home computers that could run a routine at every VBL (Vertical Blanking) interrupt, often chosen as the main timing 'tick' interrupt. Change the overscan border color for each part of the subroutine, and the timing gets reflected quite directly in the colored fringes that are displayed as the program executes.

A colleague 3D printed a stop light that showed red when Xcode was compiling and green when it was done.

Was it me??

Yes :) I almost forwarded the comment to you lolz!

you can have both and put a sound and/or light trigger to the logs with a grep and a tiny script.