International Morse alphabet
SOS in Morse code
The international distress signal is three dits, three dahs, three dits.
...---...dit dit dit dah dah dah dit dit dit
30 second sound drill
Listen to the complete rhythm. Do not count its parts.
Ready
Hear SOS as one sound
At 20 WPM, the elements join into a recognizable audio shape. Farnsworth spacing leaves time after the complete character without changing that shape.