The Morse code symbol for the letter S consists of three dots (. . .). As one of the simplest characters in International Morse code, it can be converted to a signal consisting of three dot signals. This makes it an ideal starting point for those learning Morse code.
Timing Rules
According to the timing rules that govern how we interpret the dots and dashes, a dash lasts 3 times the duration of a dot. The shortest possible signal unit is the dot, which means that the three dots of S are the shortest possible time unit within a letter. In addition, there’s a very short space between the individual signals within a letter. This very short space distinguishes the three dots of S from three separate letters.
SOS Significance
There’s another reason that the letter S stands out. It forms the opening and closing element of the internationally recognized SOS distress signal. This sequence (SOS) consists of three short sounds (S), three longer sounds (O), and then three short sounds (S) again. There’s often a pause between each letter. Three short taps, three long taps, three short taps—this is what you hear during an emergency.
How To Recognize S By Ear
If you’re just beginning to learn Morse code, you’ll want to try to recognize each character by ear. One way to do this is to practice the rhythm of the signals, associating them with the actual letter. Remember that Morse code should be heard rather than read as dots and dashes; it’s intended to be interpreted via the ear.
One of the tools you can use to learn Morse code by ear is Farnsworth speed. Adjusting the space between the letters and the words can make learning easier by allowing your ears to distinguish the difference between separate signals. You can use any number of different tools to learn Morse code: they can play, flash, or vibrate the code to teach you its patterns.