feat(voice): voice-mode prompt, isolated session, units, verbal voice swap, fast barge-in

Second voice UX iteration. Targets Marius's live-test pain points from today.

- **Voice-mode system prompt** (personality/VOICE_MODE.md, plumbed via
  claude_session.build_system_prompt(voice_mode=True)) — when the voice
  adapter starts a session, append voice-tailored instructions: short replies,
  no markdown, no abbreviations, time without seconds, distances rounded
  to "mii"/"milioane", no curly quotes / em-dash / ellipsis. Marius asked
  for a "in-the-car friend" persona for voice.

- **Isolated voice session key** (router.py) — voice mode uses
  `voice:<channel_id>` so it doesn't share context with the text adapter
  on the same Discord channel. Fresh start, voice prompt applied
  automatically without `/clear` ceremony. `/clear` drops both keys.

- **Metric units + Romanian thousands** (src/voice/normalize.py) —
  `384.000 km` was being read as "trei sute optzeci și patru virgulă zero
  zero zero km" because the dot was treated as decimal separator and `km`
  wasn't expanded. New `normalize_thousands` collapses Romanian thousands
  separators (`X.000`/`X.000.000`) before number expansion, and
  `expand_units` handles km/kg/cm/mm/ml/ha/mp with correct Romanian
  pluralization ("un kilometru", "două kilograme", "douăzeci de
  centimetri", "o sută de kilometri" with "de" particle).

- **`/voice setvoice <M1-F5>` slash command** (discord_voice.py) — Discord
  native autocomplete; swaps the live TTSQueue voice_id AND persists
  voice.default_voice to config.json. No restart needed.

- **Verbal voice change** (src/voice/voice_commands.py — new module +
  29 tests) — say "schimbă vocea pe M5" / "vorbește cu vocea F3" / "voce
  em cinci" from inside the voice channel. Detector requires both a
  trigger word (voce/vorbește/schimbă/treci pe) and a recognizable voice
  ID (direct "M5", word form "em cinci", or fallback substring match for
  Whisper-mangled forms like "unul cinci"=M5 and "Mâcinci"=M5). On
  detection: live-swap, persist to config, mirror to chat with
  `🎤 ... / 🔊 Voce → M5`, speak short ack in the NEW voice, skip
  Claude. "pământinci" still can't be recovered (no recoverable digit
  substring); user gets passthrough to Claude in that case.

- **Whisper initial_prompt** now lists the voice-command vocabulary so
  STT biases toward producing clean "M5" / "F3" tokens instead of
  inventing "pământ" / "unul" phonetic neighbors.

- **Fast barge-in** (pipeline.py EchoVoiceSink) — previously `ttsq.clear()`
  only fired in `on_segment_done` (after 800ms silence + 2-3s STT ≈ 3s lag).
  Now also fires from the sink as soon as VAD detects ≥2 consecutive
  windows (~200ms) of sustained speech on Marius's user while Echo has
  pending TTS frames. Single-window glitches don't cut Echo off; sustained
  speech does. (Acoustic echo bleed-through still requires headphones —
  no AEC in the bot.)

- Tests: 130 voice + router tests pass; updated test_router.py to expect
  `/clear` to drop both text and voice session keys.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

config.json

@@ -105,9 +105,11 @@
     "url": "http://10.0.20.161:11434"
   },
   "voice": {
-    "allowed_user_ids": ["949388626146517022"],
+    "allowed_user_ids": [
+      "949388626146517022"
+    ],
     "user_name": "Marius",
-    "default_voice": "M2",
+    "default_voice": "M5",
     "auto_leave_minutes": 5
   },
   "paths": {

personality/VOICE_MODE.md

@@ -0,0 +1,30 @@
+# Voice Mode
+
+Răspunzi prin voce (TTS). Marius te aude — nu citește. Reguli care contează:
+
+## Lungime și ton
+
+- **Scurt**: 1-2 propoziții, max ~30 cuvinte per turn. Marius vorbește cu tine — nu redactezi un document.
+- **Conversațional**: ca un om viu. Fără "Sigur, iată...", "Permite-mi să...", "Te rog să...". Direct la subiect.
+- **Fără markdown**: zero bullet points, zero `**bold**`, zero ``code blocks``, zero linkuri. Totul e citit cu voce.
+
+## Numere și unități
+
+- **Ora**: fără secunde. Spune "ora 23 și 9 minute" sau "9 și jumătate", nu "23:09:42".
+- **Distanțe mari**: rotunjește în "mii" sau "milioane". Pentru Pământ-Lună spune "384 mii de kilometri", nu "384.000 km".
+- **Zecimale**: omite-le când nu adaugă informație. "5 lei" nu "5,00 lei". "două ore" nu "2,0 ore". "20 de minute" nu "20,5 minute".
+- **Unități scrise**: pipeline-ul TTS expandează `km`/`kg`/`cm`/`mm`/`ml`/`ha`/`mp` automat, dar evită abrevieri rare. Scrie "metri" nu "m." dacă e ambiguu.
+
+## Structură
+
+- Listă scurtă verbală: "Trei lucruri: întâi X, apoi Y, plus Z."
+- Listă lungă: spune 1-2 propoziții esențiale prin voce, restul scrie în chat cu o frază tip "Restul l-am scris în chat".
+- Întrebări clarificatoare: pune UNA, nu trei.
+
+## Punctuație
+
+- Doar virgule și puncte. Fără `„` `"` `—` `…` `«»` — pipeline-ul oricum le sanitizează, dar evită-le să eviți pauzele forțate.
+
+## Tu ești Marius's prieten în mașină
+
+Imaginează-ți că Marius conduce și te-a întrebat ceva pe difuzor. Răspunzi natural, scurt, la subiect — fără ceremonii.

src/adapters/discord_voice.py

@@ -246,6 +246,45 @@ def register(tree: app_commands.CommandTree, bot: discord.Client) -> app_command
             log.warning("Presence reset skipped", exc_info=True)
         await interaction.followup.send("Plecat.", ephemeral=True)
 
+    _VOICE_CHOICES = [
+        app_commands.Choice(name=v, value=v)
+        for v in ("M1", "M2", "M3", "M4", "M5", "F1", "F2", "F3", "F4", "F5")
+    ]
+
+    @voice_group.command(name="setvoice", description="Schimbă vocea Echo (M1-M5 sau F1-F5)")
+    @app_commands.describe(voice="Voce nouă")
+    @app_commands.choices(voice=_VOICE_CHOICES)
+    async def setvoice(
+        interaction: discord.Interaction,
+        voice: app_commands.Choice[str],
+    ) -> None:
+        await interaction.response.defer(ephemeral=True)
+        new_voice = voice.value
+        # Live-swap on the active session if Echo is in voice on this guild.
+        guild_id = interaction.guild.id if interaction.guild else None
+        session = _voice_sessions.get(guild_id) if guild_id is not None else None
+        live_swapped = False
+        if session is not None and session.ttsq is not None:
+            session.ttsq.voice_id = new_voice
+            live_swapped = True
+        # Persist as the new default for future sessions.
+        try:
+            cfg = Config()
+            cfg.set("voice.default_voice", new_voice)
+            cfg.save()
+        except Exception as e:
+            log.warning("config save failed for new default voice: %s", e)
+            await interaction.followup.send(
+                f"Voce schimbată live ({new_voice}), dar config-ul nu s-a salvat: {e}",
+                ephemeral=True,
+            )
+            return
+        if live_swapped:
+            msg = f"Vocea schimbată **live** pe {new_voice}. Următoarea frază va folosi vocea nouă."
+        else:
+            msg = f"Default voce setată {new_voice}. Va intra în vigoare la următorul /voice join."
+        await interaction.followup.send(msg, ephemeral=True)
+
     @voice_group.command(name="doctor", description="Verifică voice stack")
     async def doctor(interaction: discord.Interaction) -> None:
         await interaction.response.defer(ephemeral=True)

src/claude_session.py

@@ -399,15 +399,23 @@ def _run_claude(
 # ---------------------------------------------------------------------------
 
 
-def build_system_prompt() -> str:
+def build_system_prompt(voice_mode: bool = False) -> str:
-    """Concatenate personality/*.md files into a single system prompt."""
+    """Concatenate personality/*.md files into a single system prompt.
+
+    When ``voice_mode=True``, appends ``VOICE_MODE.md`` so the model knows
+    its reply will be read aloud (terse, no markdown, no abbreviations, etc.).
+    """
     if not PERSONALITY_DIR.is_dir():
         raise FileNotFoundError(
             f"Personality directory not found: {PERSONALITY_DIR}"
         )
 
+    files = list(PERSONALITY_FILES)
+    if voice_mode:
+        files.append("VOICE_MODE.md")
+
     parts: list[str] = []
-    for filename in PERSONALITY_FILES:
+    for filename in files:
         filepath = PERSONALITY_DIR / filename
         if filepath.is_file():
             parts.append(filepath.read_text(encoding="utf-8"))
@@ -434,6 +442,7 @@ def start_session(
     model: str = DEFAULT_MODEL,
     timeout: int = DEFAULT_TIMEOUT,
     on_text: Callable[[str], None] | None = None,
+    voice_mode: bool = False,
 ) -> tuple[str, str]:
     """Start a new Claude CLI session for a channel.
 
@@ -441,13 +450,16 @@ def start_session(
 
     If *on_text* is provided, each intermediate Claude text block is passed
     to the callback as soon as it arrives.
+
+    *voice_mode* — when True, ``VOICE_MODE.md`` is appended to the system
+    prompt so the model produces short, TTS-friendly responses.
     """
     if model not in VALID_MODELS:
         raise ValueError(
             f"Invalid model '{model}'. Must be one of: haiku, sonnet, opus"
         )
 
-    system_prompt = build_system_prompt()
+    system_prompt = build_system_prompt(voice_mode=voice_mode)
 
     # Wrap external user message with injection protection markers
     wrapped_message = f"[EXTERNAL CONTENT]\n{message}\n[END EXTERNAL CONTENT]"
@@ -578,6 +590,7 @@ def send_message(
     model: str = DEFAULT_MODEL,
     timeout: int = DEFAULT_TIMEOUT,
     on_text: Callable[[str], None] | None = None,
+    voice_mode: bool = False,
 ) -> str:
     """High-level convenience: auto start or resume based on channel state.
 
@@ -598,7 +611,8 @@ def send_message(
         if session is not None and session.get("model"):
             effective_model = session["model"]
         response_text, _session_id = start_session(
-            channel_id, message, effective_model, timeout, on_text=on_text
+            channel_id, message, effective_model, timeout,
+            on_text=on_text, voice_mode=voice_mode,
         )
         return response_text
 

src/router.py

@@ -123,8 +123,10 @@ def route_message(
     # Text-based commands (not slash commands — these work in any adapter)
     if text.lower() == "/clear":
         default_model = _get_config().get("bot.default_model", "sonnet")
-        cleared = clear_session(channel_id)
+        cleared_text = clear_session(channel_id)
-        if cleared:
+        # Also drop the isolated voice session if one exists on this channel.
+        clear_session(f"voice:{channel_id}")
+        if cleared_text:
             return f"Session cleared. Model reset to {default_model}.", True
         return "No active session.", True
 
@@ -159,12 +161,19 @@ def route_message(
     # (Engineering decision #14 in the plan.) Only the discord-voice adapter
     # triggers it — text adapters keep the message verbatim.
     claude_text = text
-    if adapter_name == "discord-voice":
+    voice_mode = adapter_name == "discord-voice"
+    if voice_mode:
         user_name = _get_config().get("voice.user_name", "user") or "user"
         claude_text = f"[speaker:{user_name}] {text}"
+    # Voice sessions use an isolated session key so they start fresh with
+    # VOICE_MODE.md and don't pollute the text channel's conversation.
+    session_key = f"voice:{channel_id}" if voice_mode else channel_id
 
     try:
-        response = send_message(channel_id, claude_text, model=model, on_text=on_text)
+        response = send_message(
+            session_key, claude_text, model=model, on_text=on_text,
+            voice_mode=voice_mode,
+        )
         _set_last_response(channel_id, response)
         return response, False
     except Exception as e:

src/voice/normalize.py

@@ -94,6 +94,55 @@ def expand_numbers_ro(text: str) -> str:
     return _NUM_TOKEN.sub(_sub, text)
 
 
+# ---------- Thousands separator ----------
+
+# Romanian uses dot or space as thousands separator: 384.000 / 384 000. The
+# decimal expander would read "384.000" as "trei sute optzeci și patru virgulă
+# zero zero zero" — wrong. Collapse the dots so expand_numbers_ro reads the
+# whole integer.  Only 1-3 leading digits followed by ≥1 group of exactly 3
+# digits, never adjacent to other digits.
+_THOUSANDS_DOT = re.compile(r'(?<!\d)(\d{1,3}(?:\.\d{3})+)(?!\d)')
+
+
+def normalize_thousands(text: str) -> str:
+    """Strip the dot from Romanian thousands-separator integers."""
+    return _THOUSANDS_DOT.sub(lambda m: m.group(1).replace('.', ''), text)
+
+
+# ---------- Metric units ----------
+
+# (regex_matching_<n><unit>, singular, plural). Matches an integer or decimal
+# followed by the abbreviation as a whole word. Skipping bare ``m`` and ``l``
+# because they collide with too many tokens ("M2" voice id, list markers).
+_UNIT_PATTERNS: list[tuple[re.Pattern, str, str]] = [
+    (re.compile(r'(?<!\w)(\d+(?:[.,]\d+)?)\s*km\b', re.IGNORECASE), 'kilometru', 'kilometri'),
+    (re.compile(r'(?<!\w)(\d+(?:[.,]\d+)?)\s*kg\b', re.IGNORECASE), 'kilogram', 'kilograme'),
+    (re.compile(r'(?<!\w)(\d+(?:[.,]\d+)?)\s*cm\b', re.IGNORECASE), 'centimetru', 'centimetri'),
+    (re.compile(r'(?<!\w)(\d+(?:[.,]\d+)?)\s*mm\b', re.IGNORECASE), 'milimetru', 'milimetri'),
+    (re.compile(r'(?<!\w)(\d+(?:[.,]\d+)?)\s*ml\b', re.IGNORECASE), 'mililitru', 'mililitri'),
+    (re.compile(r'(?<!\w)(\d+(?:[.,]\d+)?)\s*ha\b', re.IGNORECASE), 'hectar', 'hectare'),
+    (re.compile(r'(?<!\w)(\d+(?:[.,]\d+)?)\s*mp\b', re.IGNORECASE), 'metru pătrat', 'metri pătrați'),
+]
+
+
+def _format_unit(amount_str: str, singular: str, plural: str) -> str:
+    """Mirror ``_format_currency_unit`` for metric units. Decimals fall through
+    to the generic decimal expander (which leaves them with plural form)."""
+    if '.' in amount_str or ',' in amount_str:
+        return f"{_decimal_to_ro(amount_str.replace(',', '.'))} {plural}"
+    return _format_currency_unit(int(amount_str), singular, plural)
+
+
+def expand_units(text: str) -> str:
+    """Expand metric unit abbreviations into spoken Romanian."""
+    for pattern, singular, plural in _UNIT_PATTERNS:
+        text = pattern.sub(
+            lambda m, sg=singular, pl=plural: _format_unit(m.group(1), sg, pl),
+            text,
+        )
+    return text
+
+
 # ---------- Time ----------
 
 _TIME_PATTERN = re.compile(r'(?<!\d)([01]?\d|2[0-3]):([0-5]?\d)(?!\d)')
@@ -257,8 +306,10 @@ def normalize_for_tts(text: str) -> str:
     text = strip_markdown(text)
     text = sanitize_punctuation(text)
     text = expand_abbreviations(text)
+    text = normalize_thousands(text)
     text = expand_time(text)
     text = expand_currency(text)
+    text = expand_units(text)
     text = expand_numbers_ro(text)
     text = expand_symbols(text)
     words = text.split()

src/voice/pipeline.py

@@ -34,6 +34,7 @@ from typing import Any, Callable, Optional
 import numpy as np
 
 from src.voice._discord_voice_adapter import AudioSink, VoiceData
+from src.voice.voice_commands import detect_voice_change
 
 log = logging.getLogger(__name__)
 
@@ -274,6 +275,12 @@ class VoiceSession:
         except Exception as e:  # noqa: BLE001
             log.warning("ttsq.clear failed: %s", e)
 
+        # In-band voice command: change TTS voice without round-tripping Claude.
+        new_voice = detect_voice_change(text)
+        if new_voice is not None:
+            await self._handle_voice_change(speaker_name, text, new_voice)
+            return
+
         # 1. Mirror to text channel (one Unicode 🎤 — exception per plan).
         if self.mirror_enabled and self.text_channel is not None:
             try:
@@ -327,6 +334,45 @@ class VoiceSession:
         except Exception as e:  # noqa: BLE001
             log.error("route_message voice path failed: %s", e)
 
+    async def _handle_voice_change(
+        self, speaker_name: str, original_text: str, new_voice: str,
+    ) -> None:
+        """Apply an in-band 'change voice' command: swap live, persist to
+        config, mirror to chat, speak a short acknowledgment in the new voice.
+        Does NOT forward the utterance to Claude."""
+        # 1. Live-swap on the TTS queue. Next clause synth uses the new voice.
+        try:
+            self.ttsq.voice_id = new_voice
+        except Exception as e:  # noqa: BLE001
+            log.warning("ttsq voice swap failed: %s", e)
+        # 2. Persist as the new default for future sessions.
+        try:
+            from src.config import Config
+            cfg = Config()
+            cfg.set("voice.default_voice", new_voice)
+            cfg.save()
+        except Exception as e:  # noqa: BLE001
+            log.warning("voice default persist failed: %s", e)
+        # 3. Mirror what was heard + show the swap in the text channel.
+        if self.mirror_enabled and self.text_channel is not None:
+            try:
+                send = getattr(self.text_channel, "send", None)
+                if callable(send):
+                    coro = send(
+                        f"\U0001f3a4 {speaker_name}: \"{original_text}\"\n"
+                        f"\U0001f50a Voce → **{new_voice}**"
+                    )
+                    if asyncio.iscoroutine(coro):
+                        await coro
+            except Exception as e:  # noqa: BLE001
+                log.warning("voice mirror send failed: %s", e)
+        # 4. Verbal acknowledgment in the NEW voice.
+        try:
+            self.ttsq.push_text(f"Vocea {new_voice}.")
+        except Exception as e:  # noqa: BLE001
+            log.warning("voice ack push failed: %s", e)
+        self._log_metric({"event": "voice_change", "new_voice": new_voice})
+
     # ----- helpers -----
 
     def _resolve_speaker_name(self, speaker_id: int) -> str:
@@ -381,6 +427,10 @@ class EchoVoiceSink(AudioSink):
         # chain breaks when "I spoke but Echo heard nothing" happens.
         self._first_packet_logged: set[int] = set()
         self._first_speech_logged: set[int] = set()
+        # Track consecutive VAD-positive windows per user. Used to delay
+        # barge-in (don't cut Echo off on a single jittery VAD hit; require
+        # ≥2 windows ≈ 200ms of sustained speech).
+        self._vad_consecutive: dict[int, int] = {}
         # Background poller that triggers the silence flush even when Discord
         # DTX stops delivering RTP packets after the user stops speaking. Without
         # this, sink.write would stop firing and STT would never run on the
@@ -444,9 +494,27 @@ class EchoVoiceSink(AudioSink):
                     if uid not in self._first_speech_logged:
                         self._first_speech_logged.add(uid)
                         log.info("voice sink: VAD detected speech from user %s", uid)
+                    self._vad_consecutive[uid] = self._vad_consecutive.get(uid, 0) + 1
                     with self._sink_lock:
                         self._last_speech_ts[uid] = time.monotonic()
                         self._has_speech[uid] = True
+                    # Fast barge-in: after ≥2 consecutive VAD windows (~200ms
+                    # of sustained speech), cut Echo's TTS mid-sentence so the
+                    # user doesn't have to wait the full silence-flush + STT
+                    # cycle (~3s).
+                    if self._vad_consecutive[uid] >= 2:
+                        try:
+                            ttsq = self.session.ttsq
+                            if ttsq is not None and not ttsq.is_empty():
+                                ttsq.clear()
+                                log.info(
+                                    "voice sink: barge-in cleared TTS queue (user=%s)",
+                                    uid,
+                                )
+                        except Exception as e:  # noqa: BLE001
+                            log.warning("barge-in clear failed: %s", e)
+                else:
+                    self._vad_consecutive[uid] = 0
 
             pcm_for_stt = self._take_flushable_pcm(uid)
             if pcm_for_stt:
@@ -530,7 +598,10 @@ class EchoVoiceSink(AudioSink):
                 mono16, language="ro", beam_size=5,
                 initial_prompt=(
                     "Echo Core, asistent personal AI românesc al lui Marius. "
-                    "Conversație colocvială în română."
+                    "Conversație colocvială în română. "
+                    "Comenzi voce recunoscute: schimbă vocea pe M1, M2, M3, M4, M5, "
+                    "F1, F2, F3, F4, F5. Exemple: vorbește cu vocea M5, voce F3, "
+                    "treci pe vocea F1."
                 ),
                 condition_on_previous_text=False,
             )

src/voice/voice_commands.py

@@ -0,0 +1,118 @@
+"""Detect in-band voice commands from STT transcripts.
+
+The voice pipeline transcribes Marius's speech via Whisper and dispatches the
+text to Claude. Some utterances are not questions for Claude — they're
+control commands for the voice stack itself. This module parses those out
+*before* the Claude round-trip so they take effect instantly and don't waste
+a Claude session turn.
+
+Currently handled:
+  * change TTS voice — "schimbă vocea pe M5", "vorbește cu vocea F3",
+    "voce em cinci", "voce feminină 3", etc.
+
+The parser is intentionally conservative: it requires BOTH a voice trigger
+word ("voce", "vorbește", "schimbă", "treci pe") AND a recognizable voice
+ID. A bare "M5" without context is NOT a command — Marius might be quoting
+a string.
+"""
+from __future__ import annotations
+
+import re
+from typing import Optional
+
+
+_VALID_VOICES = {f"M{i}" for i in range(1, 6)} | {f"F{i}" for i in range(1, 6)}
+
+
+# Trigger words that suggest the user is talking ABOUT the voice, not just
+# saying something that happens to contain a voice-ID-looking substring.
+_VOICE_TRIGGER_RE = re.compile(
+    r'\b(voce|vocea|voci|voice|vorbe[șs]te|schimb[aăÎ]|treci\s+pe)\b',
+    re.IGNORECASE,
+)
+
+# Direct form: "M5", "F 3", "m5", etc.
+_VOICE_ID_DIRECT_RE = re.compile(
+    r'\b([MF])\s*([1-5])\b',
+    re.IGNORECASE,
+)
+
+# Word form: "em cinci", "M trei", "masculin doi", "feminină patru", etc.
+# Whisper often transcribes "M5" as "em cinci" / "M cinci" because letter
+# names are spelled out phonetically in Romanian.
+_VOICE_ID_WORDS_RE = re.compile(
+    r'\b(em|m|masculin[aăe]?|ef|f|feminin[aăe]?)\s+(unu|una|doi|dou[ăa]|trei|patru|cinci|[1-5])\b',
+    re.IGNORECASE,
+)
+
+
+_DIGIT_WORD_TO_INT = {
+    'unu': 1, 'una': 1, 'unul': 1, '1': 1,
+    'doi': 2, 'două': 2, 'doua': 2, '2': 2,
+    'trei': 3, '3': 3,
+    'patru': 4, '4': 4,
+    'cinci': 5, '5': 5,
+}
+
+# Substring fallback: matches digit roots even when Whisper glues them into
+# compound non-words like "Mâcinci" (for "M cinci"=M5).
+_DIGIT_SUBSTR_RE = re.compile(
+    r'(cinci|patru|trei|dou[ăa]|unul|unu|una)',
+    re.IGNORECASE,
+)
+
+_F_GENDER_HINT_RE = re.compile(r'feminin|\bef\b|\bF\d?\b', re.IGNORECASE)
+
+
+def _normalize_gender(word: str) -> Optional[str]:
+    """Map gender word to 'M' or 'F'."""
+    w = word.lower()
+    if w in ('m', 'em') or w.startswith('masculin'):
+        return 'M'
+    if w in ('f', 'ef') or w.startswith('feminin'):
+        return 'F'
+    return None
+
+
+def detect_voice_change(text: str) -> Optional[str]:
+    """Parse a transcript for a 'change voice' command.
+
+    Returns the target voice id (one of M1-M5, F1-F5) or None if no command
+    was detected. Requires both a voice trigger word and a voice ID.
+    """
+    if not text:
+        return None
+    if not _VOICE_TRIGGER_RE.search(text):
+        return None
+    # Try the direct form first (M5, F3, etc.)
+    m = _VOICE_ID_DIRECT_RE.search(text)
+    if m:
+        candidate = f"{m.group(1).upper()}{m.group(2)}"
+        if candidate in _VALID_VOICES:
+            return candidate
+    # Fall back to the word form ("em cinci", "feminin trei", ...).
+    m = _VOICE_ID_WORDS_RE.search(text)
+    if m:
+        gender = _normalize_gender(m.group(1))
+        digit = _DIGIT_WORD_TO_INT.get(m.group(2).lower())
+        if gender is not None and digit is not None:
+            candidate = f"{gender}{digit}"
+            if candidate in _VALID_VOICES:
+                return candidate
+    # Permissive fallback: Whisper sometimes glues the letter into the next
+    # word ("Mâcinci" for "M cinci") or replaces it ("unul cinci" for
+    # "M unu cinci"). After a voice trigger word, scan for any digit-word
+    # substring and infer gender (F if a feminine marker is present, else M).
+    digit_hits = _DIGIT_SUBSTR_RE.findall(text)
+    digits = [_DIGIT_WORD_TO_INT[d.lower()] for d in digit_hits
+              if d.lower() in _DIGIT_WORD_TO_INT]
+    digits = [d for d in digits if 1 <= d <= 5]
+    if digits:
+        gender = 'F' if _F_GENDER_HINT_RE.search(text) else 'M'
+        # Last digit wins — handles "M unu cinci" → M5 since "unu" is a
+        # mangled letter-name prefix, "cinci" is the actual target.
+        return f"{gender}{digits[-1]}"
+    return None
+
+
+__all__ = ["detect_voice_change"]

tests/test_router.py

@@ -30,7 +30,10 @@ class TestClearCommand:
         response, is_cmd = route_message("ch-1", "user-1", "/clear")
         assert response == "Session cleared. Model reset to sonnet."
         assert is_cmd is True
-        mock_clear.assert_called_once_with("ch-1")
+        # /clear drops both the text-adapter session and the isolated voice
+        # session for the same Discord channel.
+        mock_clear.assert_any_call("ch-1")
+        mock_clear.assert_any_call("voice:ch-1")
 
     @patch("src.router._get_config")
     @patch("src.router.clear_session")
@@ -191,7 +194,7 @@ class TestRegularMessage:
         response, is_cmd = route_message("ch-1", "user-1", "hello")
         assert response == "Hello from Claude!"
         assert is_cmd is False
-        mock_send.assert_called_once_with("ch-1", "hello", model="sonnet", on_text=None)
+        mock_send.assert_called_once_with("ch-1", "hello", model="sonnet", on_text=None, voice_mode=False)
 
     @patch("src.router.send_message")
     def test_model_override(self, mock_send):
@@ -199,7 +202,7 @@ class TestRegularMessage:
         response, is_cmd = route_message("ch-1", "user-1", "hello", model="opus")
         assert response == "Response"
         assert is_cmd is False
-        mock_send.assert_called_once_with("ch-1", "hello", model="opus", on_text=None)
+        mock_send.assert_called_once_with("ch-1", "hello", model="opus", on_text=None, voice_mode=False)
 
     @patch("src.router._get_channel_config")
     @patch("src.router._get_config")
@@ -227,7 +230,7 @@ class TestRegularMessage:
 
         cb = lambda t: None
         route_message("ch-1", "user-1", "hello", on_text=cb)
-        mock_send.assert_called_once_with("ch-1", "hello", model="sonnet", on_text=cb)
+        mock_send.assert_called_once_with("ch-1", "hello", model="sonnet", on_text=cb, voice_mode=False)
 
 
 # --- _get_channel_config ---
@@ -269,7 +272,7 @@ class TestModelResolution:
         mock_chan_cfg.return_value = {"id": "ch-1", "default_model": "haiku"}
 
         route_message("ch-1", "user-1", "hello")
-        mock_send.assert_called_once_with("ch-1", "hello", model="haiku", on_text=None)
+        mock_send.assert_called_once_with("ch-1", "hello", model="haiku", on_text=None, voice_mode=False)
 
     @patch("src.router._get_channel_config")
     @patch("src.router._get_config")
@@ -283,7 +286,7 @@ class TestModelResolution:
         mock_get_config.return_value = mock_cfg
 
         route_message("ch-1", "user-1", "hello")
-        mock_send.assert_called_once_with("ch-1", "hello", model="opus", on_text=None)
+        mock_send.assert_called_once_with("ch-1", "hello", model="opus", on_text=None, voice_mode=False)
 
     @patch("src.router._get_channel_config")
     @patch("src.router._get_config")
@@ -297,7 +300,7 @@ class TestModelResolution:
         mock_get_config.return_value = mock_cfg
 
         route_message("ch-1", "user-1", "hello")
-        mock_send.assert_called_once_with("ch-1", "hello", model="sonnet", on_text=None)
+        mock_send.assert_called_once_with("ch-1", "hello", model="sonnet", on_text=None, voice_mode=False)
 
     @patch("src.router.get_active_session")
     @patch("src.router.send_message")
@@ -307,4 +310,4 @@ class TestModelResolution:
         mock_get_session.return_value = {"model": "opus", "session_id": "abc"}
 
         route_message("ch-1", "user-1", "hello")
-        mock_send.assert_called_once_with("ch-1", "hello", model="opus", on_text=None)
+        mock_send.assert_called_once_with("ch-1", "hello", model="opus", on_text=None, voice_mode=False)

tests/test_voice_commands.py

@@ -0,0 +1,55 @@
+"""Tests for src/voice/voice_commands.detect_voice_change."""
+from __future__ import annotations
+
+import pytest
+
+from src.voice.voice_commands import detect_voice_change
+
+
+class TestDetectVoiceChange:
+    # --- positive cases (direct form) ---
+    @pytest.mark.parametrize("text,expected", [
+        ("schimbă vocea pe M5", "M5"),
+        ("Schimbă vocea pe F3.", "F3"),
+        ("vorbește cu vocea M1", "M1"),
+        ("vorbește cu vocea F2", "F2"),
+        ("voce M4", "M4"),
+        ("Voce F5.", "F5"),
+        ("treci pe vocea F1", "F1"),
+        ("Echo, treci pe M2.", "M2"),
+        ("voice M3", "M3"),
+    ])
+    def test_direct_form(self, text, expected):
+        assert detect_voice_change(text) == expected
+
+    # --- positive cases (word form, what Whisper actually produces) ---
+    @pytest.mark.parametrize("text,expected", [
+        ("schimbă vocea pe em cinci", "M5"),
+        ("vorbește cu vocea em trei", "M3"),
+        ("voce em unu", "M1"),
+        ("schimbă vocea pe ef doi", "F2"),
+        ("voce ef cinci", "F5"),
+        ("vorbește cu vocea masculină cinci", "M5"),
+        ("schimbă vocea pe feminină trei", "F3"),
+        ("voce masculin patru", "M4"),
+        ("schimbă vocea pe M cinci", "M5"),
+        ("voce F două", "F2"),
+    ])
+    def test_word_form(self, text, expected):
+        assert detect_voice_change(text) == expected
+
+    # --- negative cases ---
+    @pytest.mark.parametrize("text", [
+        "",
+        "cât este ora",
+        "M5",                          # no trigger word
+        "Salut Echo, sunt în M3",       # M3 here is a location/etc, no trigger
+        "vocea ta este foarte bună",    # trigger but no voice id
+        "schimbă te rog",               # trigger but no id
+        "voce M6",                      # out of range
+        "voce M0",                      # out of range
+        "voce F8",                      # out of range
+        "schimbă vocea pe șapte",       # digit out of range
+    ])
+    def test_no_match(self, text):
+        assert detect_voice_change(text) is None