The dot as the base unit
Every duration begins with one timing unit. A dot occupies one unit. A dash occupies three. The ratio, not an absolute number of milliseconds, defines the symbol.
At a faster sending speed the unit becomes shorter, but the one-to-three relationship remains. This proportional model lets the same alphabet work from deliberate training speeds to rapid expert communication.
Three kinds of silence
The gap between dots and dashes within one character is one unit. The gap between complete characters is three units. The gap between words is seven units.
Silence is therefore encoded structure. If a sender uses a three-unit pause inside a character, the receiver may hear two characters. If word spacing is too short, separate words merge into an ambiguous stream.
Calculating a unit from WPM
A common PARIS convention defines one standard word as fifty timing units. This produces the familiar approximation that one dot unit in seconds equals 1.2 divided by words per minute.
At 12 WPM, a dot is about 100 milliseconds and a dash about 300. At 20 WPM, a dot is about 60 milliseconds. Implementations should calculate from one base unit so every mark and gap changes consistently.
Character speed and effective speed
Learners may benefit from characters played at a reasonably brisk internal speed while extra silence lowers the overall text rate. This preserves each character’s audible shape and reduces the temptation to count.
This approach is often associated with Farnsworth spacing. The interface should distinguish character speed from effective message speed whenever both are adjustable, otherwise a WPM label can mislead the learner.
Audio frequency and envelope
Pitch is normally expressed in hertz. It affects listening comfort but not Morse meaning. Many users find a mid-range sine tone clear, while individual hearing and equipment can make another frequency preferable.
A generated tone should avoid abrupt clicks where practical by using a short amplitude envelope. That acoustic polish must not lengthen the signal enough to distort the standardized timing ratios.
Human sending variation
Real operators do not produce mathematically perfect marks. Small variation is normal, and experienced listeners recognize rhythm despite it. Excessive compression, drifting dash length, or inconsistent gaps eventually causes ambiguity.
Training should reward readability rather than machine-like rigidity. Record and replay sending, compare boundaries, and correct recurring patterns such as shortened word gaps or dashes that approach dot length.
Timing in audio decoding
A decoder estimates tone regions and silence regions, then clusters their durations into likely units. Noise, fading, echoes, clipped recordings, and changing speed can make that inference uncertain.
A trustworthy result reports confidence and shows detected Morse. Advanced settings may guide frequency or threshold detection, but they should remain secondary to a simple default workflow.
Practice with timing
Choose a short word, hear it once, and tap its rhythm. Then inspect where marks end, where letters end, and where the word ends. Repeat slowly without stretching individual characters into counted fragments.
Use the interactive chart for isolated rhythms, the translator for custom text, and the speed test for controlled progression. Accuracy, stable spacing, and relaxed recognition should improve together.
Sources and further reading
- International Telecommunication Union, Recommendation ITU-R M.1677.
- PARIS timing convention used in established Morse speed measurement.
- MorseCode.wiki audio-generation and interpretation methodology.