voice-goio docs

Phraseology and Prosody

normalise converts ATC message text written the way the application holds it into what a controller says:

BAW123 climb FL350 → Speedbird one two tree, climb flight level tree fife zero

It covers ICAO and FAA phraseology (voicegoio.ICAO, voicegoio.FAA), emergency signals, METAR shorthand and the pauses.

Pauses are the normaliser’s job

Both piper (through espeak) and macOS say take their pauses from punctuation, so inserting commas at semantic boundaries is the only lever there is. The normaliser adds one after a callsign, between the elements of a taxi route (TWY A3 and B → “taxiway alpha tree, bravo”), after a distress signal, and between an information unit and the instruction that follows it. That last rule keys off having just finished a keyword group rather than off the verb alone, which is what stops radar contact becoming “radar, contact”.

Emergencies

The library pronounces what the application writes and does not rewrite phraseology, so the application sends the real thing — MAYDAY MAYDAY MAYDAY or PAN PAN, PAN PAN, PAN PAN. It does know that “mayday” is a one-word signal and “pan pan” a two-word one, so the pauses land between the repeats instead of inside them.

METAR shorthand and the ATIS

The normaliser speaks METAR shorthand, so a broadcast can be written the way the application already holds it — BKN020 → “broken two thousand”, 10KM BR → “one zero kilometres mist”, NOSIG → “no significant change”.

Digits

ICAO speaks 5 as “fife”, as the FL350 and SQK 4321 examples do, and the frequency 127.45 reads one two seven decimal four fife. The historic design spec §4.1 shows “five” there, contradicting its own digit table; the digit table wins. See Design notes.