Thanks for your input. To answer your questions at the end - Yes, we learned it primarily for the test, but also this was more than 20 years ago, and back then

Thanks for your input. To answer your questions at the end - Yes, we learned it primarily for the test, but also this was more than 20 years ago, and back then, the ATIS (Terminal Information System) broadcast that gave you your weather and QNH etc. would prefix every repeated recorded broadcast with the 4 letter ICAO airport code. My local airport here is YPDN (Darwin, Australia), but in larger cities with several airports, we had to verify via morse to the instructor during a flight test that we had dialled in the correct ATIS frequency by cross checking the morse ICAO code. Also, we had to do the same verification when dialling in to an NDB (Non Directional Beacon) which is about the most basic navaid available on a plane. Because the ADF (Automatic Direction Finder) on board used to dial into an NDB was in the HF radio band and thus subject to reflections off the troposphere inadvertently picking up another NDB over the horizon, we also had to listen to the repeated morse identifier of that beacon to ensure we had dialled in and were tracking the correct one. As said, only on flight tests mainly. We soon got used to the patterns of the beacons and transmissions that we used regularly and would just listen for the pattern rather than try and decipher each letter/number. EDIT: Here is a video I found recently which talks about using the binary tree method of memorising morse code, as well as another method - https://www.youtube.com/watch?v=D8tPkb98Fkk https://www.youtube.com/watch?v=D8tPkb98Fkk