christos-antono/npctalk/voice-input

Voice input

Three ways in, all ending in the same exchange: open mic (just talk), push-to-talk (hold N), type (B). Build push-to-talk first; it has no detection problems. Then the open mic, which is what makes it feel like talking to people.

Open mic (examples/gta-v/mod/OpenMic.cs)

• 16 kHz mono capture in 30 ms blocks.
• Noise floor: the quietest moments of the last 1.5 s. An utterance starts when the level stays

SensitivityDb (12 dB) above that floor for 150 ms, and ends after SilenceMs (700 ms) below it. The floor adapts to the room and to the game's own sound.

• Keep 300 ms from before the start, so the first syllable isn't cut.
• Drop anything shorter than 450 ms (coughs, clicks) and anything over 12 s without a pause (music, a loud game).
• Pause while an NPC talks, and for 600 ms after: their voice comes out of the speakers and would be

transcribed as the player's. Also pause while push-to-talk is held, while typing, and while a reply is being written. Headphones make this much easier.

• Drop non-speech after transcribing: one-word fillers ("uh", "um", "hmm", "yeah", "okay", "thanks"...) and

empty transcripts are ignored (open mic ignored, not speech: in the log).

Who it goes to

Whoever the target lookup returns at that moment (skill make-npcs-talk, hook 1): within 5 m, or looked at within 12 m; the last partner sticks while close. If nobody's there, log it ("open mic -> nobody near") and show it on screen ("Listening... (to nobody near you)"), or the player thinks the mic is broken.

Speech-to-text

fal nvidia/nemotron-asr-multilingual/asr: send the WAV inline as a data URI (no upload step), ~0.4 s for a short sentence (0.38-0.80 s logged). Returns output or text. Whisper (any host) is the alternative; whatever you use, measure it per exchange.

Things that look like bugs

• "Nobody answers" with people around: is the mod on? A toggle key that switches everything off looks

exactly like a broken mic. Show the off state on screen. Then check the target rules (are they within 5 m or in front of the camera?).

• The NPC answers the room. The open mic hears everything: a call, music, someone else talking. Give the

player a mute key (M) and show the mic state on screen.

• It triggers on the game. Raise SensitivityDb, or use headphones.
• First word missing: the pre-roll is too short or the start threshold too slow.

Test without the game

npcvoice-check vad <voices folder> runs the detector on real voice clips mixed over quiet and loud noise, and reports what it caught and cut.