I was recently facing a real issue with audible phone notifications. For those that I do have enabled, I needed to quickly distinguish what just came in, and possibly from whom, because I need to react to some of them immediately, and I may not have my phone on me at all times, but it may be within earshot.

I needed some dozen of short, reasonably unobtrusive but distinct sounds. You know where this is going.

I ended up assigning a set of two-letter codes, first letter = source, second = same letter for generic, others for specific initials, so things like NN = other, EE = email, WW = WhatsApp, TB = text message from Bob.

When generating the Morse WAVs I set it to 40 WPM where longer sequences mostly blur into "outlines", but they are short, so I manage, and I added some 0.3 s padding on both ends to account for things like sound ducking and other hiccups. Works great.