Huddles are English-only: neither transcription nor speech can be switched to another language

[HolgerGERMANY]

Type: feature request (with a concrete blocker)
Component: desktop (huddle/stt.rs, huddle/models.rs, crates/buzz-voice)
Date: 2026-08-07
Context: a German-speaking team running a self-hosted relay, using huddles daily

Summary

For a team that does not speak English, huddles are currently unusable as a
working tool:

• Transcription runs an English-only model. German speech is transcribed as
  English phonetics — "Transkribiere bitte deutsche Sprache" comes out as
  "Tans three Eera B Deutsche Sach". The huddle transcript is what agents read,
  so the agents receive nonsense.
• Speech runs an English-only voice model. German replies from agents are
  pronounced with English phonetics.

Neither is a setting. Both are pinned in code.

Transcription

STT_MODEL_DIR_NAME = "parakeet-tdt-ctc-110m-en", artifact
sherpa-onnx-nemo-parakeet_tdt_ctc_110m-en-36000-int8.tar.bz2
(desktop/src-tauri/src/huddle/models.rs:121-127), pinned by SHA-256. There is
no language selection anywhere in the huddle code — grep -i "language\|locale"
over desktop/src-tauri/src/huddle/ finds nothing relevant.

We tried swapping the model files for the multilingual
sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k
(same NeMo-CTC family, so it matches the nemo_ctc config in stt.rs). The app
accepted it — readiness only checks manifest version and file presence
(expected_size is |_| None for the STT slot, models.rs:397,611) — but the
output was unusable: single Cyrillic characters and periods, no words. Rolled
back. So a drop-in swap is not a viable workaround for operators either.

Speech

const MODEL_LANGUAGE: &str = "english_2026-04"
(crates/buzz-voice/src/pocket_april.rs:32), and loading fails outright on a
mismatch:

"expected Pocket TTS language {MODEL_LANGUAGE}, got {}"

Importing a reference voice (import_pocket_voice, 2–30 s of audio) changes the
timbre only — we tested it with a German speaker sample; pronunciation stays
English. There is no alternative TTS backend in the shipped code: a grep for
say|AVSpeech|NSSpeech|espeak|piper across desktop/src-tauri/src/huddle/
returns nothing.

What would help, in order of usefulness

1. A siri:/system-voice backend. The key format already appears in tests
   (huddle/tts_settings.rs: "siri:aaron"), and voice_preferences is already
   a per-backend list. On macOS the system voices cover German (and many other
   languages) at good quality, with no extra download. This alone would fix the
   speech half for every non-English team.
2. A language selector for STT, with per-language model artifacts — even a
   small set (de, fr, es) would cover most of Europe.
3. Failing both: document that huddles are English-only, so teams do not
   spend a day discovering it by experiment.

Why this matters more than it looks

The huddle transcript is posted into the huddle channel as ordinary kind:9
messages, which is what makes agents useful in a voice call — they read what was
said and answer. With an English-only transcriber, a German team's agents receive
garbage, so the whole agent-in-huddle feature collapses for them, not just the
subtitles.