If you had a good morse operator, he or she could send five different messages at once.

Bogs
John, when I was a well laddie I sent a lot of Morse code, weather reports, flight plans, passenger lists, etc. Yes, they even paid me to send and receive Morse code. We would use a typewriter when receiving and the secret for accurat work was to somehow ignore the content of the message, "sort of in the ears and out the fingers without going near the brain".
When I came to mess around with computers it was obvious that I would be writing some More code programs and I made Morse code hardware too including a keboard that converted keystrokes into audible code. Although others were suitably impressed with this device back in the '70's I found it impossible to use, I would type a word while hearing it a moment later and the word or parts of the word were repeated!

It was impossible to break the old habit.