Morse Code Converter

International Morse code was developed in the 1830s by Samuel Morse and Alfred Vail for use with the electric telegraph, one of the first long-distance communication systems. Each letter and digit is represented by a sequence of short signals (dots) and long signals (dashes). The timing ratios are standardised: a dot is 1 unit, a dash is 3 units, the gap between symbols within a letter is 1 unit, between letters is 3 units, and between words is 7 units. At 20 words per minute (WPM), one unit is approximately 60 milliseconds.

The encoding scheme that survives today is ITU-R Recommendation M.1677-1, which covers all 26 Latin letters, digits 0–9, and common punctuation. The format used by this converter separates letter symbols with spaces and words with a forward slash surrounded by spaces (e.g. `.... . .-.. .-.. --- / .-- --- .-. .-.. -..` for "HELLO WORLD").

Morse code remains operationally relevant in several fields. Amateur (ham) radio operators are tested on Morse proficiency in many countries. International aviation uses Non-Directional Beacon (NDB) identifiers broadcast in Morse. The maritime SOS distress signal, `... --- ...`, is defined in Morse. Military and special operations units use it as a fallback when voice communications are compromised.

The audio playback feature here implements correct ITU timing: the WPM slider adjusts the unit duration, and each beep uses a smooth envelope (brief fade in/out) to reduce the harsh clicking you'd hear with abrupt square waves. This makes it practical for learning and practising Morse recognition by ear.