audio cues: add master on/off switch; silence PortAudio teardown noise

Two follow-ups from hands-free testing:

- Audio cues had no off-switch: empty sound fields fall back to the freedesktop
  system chime, so wakeword/recording always made noise. Add a [sounds] enabled
  master flag (default true) exposed as "Play audio cues" in Settings → Input.
  When off, _play_cue/_play_sound are no-ops — fully silent operation.

- The VAD level meter (sounddevice/PortAudio) leaked harmless thread-teardown
  errors ("pthread_join ... failed", "PaUnixThread_Terminate ... failed") to the
  terminal on every clip end. PortAudio writes these straight to fd 2, so wrap
  the stream open/close in a fd-level stderr suppressor (_quiet_c_stderr).

Tests: cue gating respects the master switch (16 passed).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

linux/CHANGELOG.md

@@ -14,8 +14,15 @@ The version is defined in [`blitztext/__init__.py`](blitztext/__init__.py).
   system-tray menu when the wakeword is enabled. It pauses/resumes hands-free
   detection by toggling the `/tmp/wake_muted` flag (external scripts may toggle
   the same file).
+- **"Play audio cues" master switch** (Settings → Input → Audio cues, or
+  `[sounds] enabled` in the config): one toggle to silence every start/stop
+  chime, including the hands-free wakeword cues. Defaults to on.
 
 ### Fixed
+- **PortAudio/ALSA teardown noise**: the level meter no longer leaks
+  `pthread_join ... failed` / `PaUnixThread_Terminate ... failed` lines to the
+  terminal when a clip ends — that C-library chatter (written straight to fd 2)
+  is now suppressed around the stream open/close.
 - **Wakeword stuck muted**: a leftover `/tmp/wake_muted` flag silently disabled
   detection with no in-app way to clear it. The state is now exposed and
   reversible from the tray, so a stale flag no longer kills hands-free use. The

linux/blitztext/audio.py

@@ -7,11 +7,39 @@ the chosen input and report a 0..1 level to a callback.
 
 from __future__ import annotations
 
+import contextlib
+import os
 import shutil
 import subprocess
+import sys
 import threading
 
 
+@contextlib.contextmanager
+def _quiet_c_stderr():
+    """Silence chatter written directly to fd 2 by C libraries.
+
+    PortAudio/ALSA print harmless thread-teardown noise
+    ("pthread_join ... failed", "PaUnixThread_Terminate ... failed") straight to
+    the underlying stderr file descriptor, which Python-level redirection can't
+    catch. We briefly point fd 2 at /dev/null around the offending call.
+    """
+    try:
+        stderr_fd = sys.stderr.fileno()
+    except (AttributeError, ValueError, OSError):
+        yield  # No real stderr fd (already captured/redirected) — nothing to do.
+        return
+    saved_fd = os.dup(stderr_fd)
+    devnull_fd = os.open(os.devnull, os.O_WRONLY)
+    try:
+        os.dup2(devnull_fd, stderr_fd)
+        yield
+    finally:
+        os.dup2(saved_fd, stderr_fd)
+        os.close(devnull_fd)
+        os.close(saved_fd)
+
+
 def list_mics() -> list[tuple[str, str]]:
     """Return [(source_name, friendly_label)] for real input sources.
 
@@ -59,6 +87,7 @@ class LevelMeter:
                 self.on_level(min(1.0, level * 12.0))
 
         try:
+            with _quiet_c_stderr():
                 self._stream = sd.InputStream(
                     samplerate=16000, channels=1, dtype="float32",
                     blocksize=1600, device=self._resolve_device(), callback=_cb,
@@ -88,6 +117,8 @@ class LevelMeter:
         with self._lock:
             if self._stream is not None:
                 try:
+                    # PortAudio/ALSA spews thread-teardown noise to fd 2 here.
+                    with _quiet_c_stderr():
                         self._stream.stop()
                         self._stream.close()
                 finally:

linux/blitztext/config.py

@@ -52,6 +52,7 @@ class Config:
     reject_hallucinations: bool = True
     strip_trailing_punctuation: bool = False
     # audio cues (paths to WAV files; "" = built-in system sound)
+    sounds_enabled: bool = True   # master switch for all start/stop/wakeword cues
     sound_before: str = ""
     sound_after: str = ""
     # whisper
@@ -169,6 +170,7 @@ def load(path: Path = CONFIG_PATH) -> Config:
         silence_rms=float(q.get("silence_rms", 150.0)),
         reject_hallucinations=bool(q.get("reject_hallucinations", True)),
         strip_trailing_punctuation=bool(q.get("strip_trailing_punctuation", False)),
+        sounds_enabled=bool(snd.get("enabled", True)),
         sound_before=snd.get("before", ""),
         sound_after=snd.get("after", ""),
         wakeword_enabled=bool(ww.get("enabled", False)),
@@ -276,6 +278,7 @@ def save(cfg: Config, path: Path = CONFIG_PATH) -> None:
             "strip_trailing_punctuation": cfg.strip_trailing_punctuation,
         },
         "sounds": {
+            "enabled": cfg.sounds_enabled,
             "before": cfg.sound_before,
             "after": cfg.sound_after,
         },
@@ -364,9 +367,12 @@ reject_hallucinations = true
 strip_trailing_punctuation = false
 
 [sounds]
-# Optional WAV files played as audio cues. Leave empty for the built-in system
+# enabled = master switch for ALL audio cues (start/stop chimes and the
+# hands-free wakeword cues below). Set false for completely silent operation.
+# Optional WAV files played as audio cues: leave empty for the built-in system
 # sound. "before" plays when recording starts; "after" plays on any stop
 # (stop+paste, stop+paste+Enter, or auto-stop on silence).
+enabled = true
 before = ""
 after = ""
 

linux/blitztext/daemon.py

@@ -150,12 +150,17 @@ class Daemon:
             self._vad_meter = None
 
     def _play_sound(self, sound_name: str) -> None:
+        if not self.cfg.sounds_enabled:
+            return
         from . import sound
         sound.play(fallback=sound_name)
 
     def _play_cue(self, cue: str) -> None:
         """Play an audio cue. Hands-free (wakeword) sessions prefer the wakeword
-        sounds, then the general [sounds] cues, then a built-in system sound."""
+        sounds, then the general [sounds] cues, then a built-in system sound.
+        The whole feature is gated by the [sounds] master switch."""
+        if not self.cfg.sounds_enabled:
+            return
         from . import sound
         if cue == "before":
             custom = (self.cfg.wakeword_sound_detected if self._session_silent else "") or self.cfg.sound_before

linux/blitztext/gtksettings.py

@@ -773,7 +773,11 @@ class SettingsDialog:
             "Played when your command is captured (silence or stop) — confirms your input was taken.")
 
         page.pack_start(Gtk.Separator(), False, False, 8)
-        page.pack_start(Gtk.Label(label="Audio cues (manual dictation)", xalign=0.0), False, False, 2)
+        page.pack_start(Gtk.Label(label="Audio cues", xalign=0.0), False, False, 2)
+        self.snd_enabled = Gtk.Switch(); self.snd_enabled.set_active(self.cfg.sounds_enabled); self.snd_enabled.set_halign(Gtk.Align.START)
+        _labeled(page, "Play audio cues", self.snd_enabled,
+                 tooltip="Master switch for every start/stop chime, including the hands-free "
+                         "wakeword cues above. Turn off for completely silent operation.")
         self.snd_before = self._sound_field(
             page, "Play before", self.cfg.sound_before,
             "Sound played when recording starts — your confirmation that Blitztext is listening.")
@@ -1120,6 +1124,7 @@ class SettingsDialog:
             c.silence_rms = float(self.q_rms.get_text())
             c.reject_hallucinations = self.q_halluc.get_active()
             c.strip_trailing_punctuation = self.q_strip.get_active()
+            c.sounds_enabled = self.snd_enabled.get_active()
             c.sound_before = self.snd_before.get_filename() or ""
             c.sound_after = self.snd_after.get_filename() or ""
             c.wakeword_enabled = self.ww_enabled.get_active()

linux/tests/test_daemon_notify.py

@@ -43,6 +43,23 @@ def test_on_wakeword_starts_a_silent_session(monkeypatch):
     assert started.get("wf") is d._route_workflow
 
 
+def test_audio_cues_master_switch(monkeypatch):
+    import blitztext.sound as sound_mod
+    plays = []
+    monkeypatch.setattr(sound_mod, "play", lambda *a, **k: plays.append((a, k)))
+    d = _make_daemon(monkeypatch)
+
+    d.cfg.sounds_enabled = False
+    d._play_cue("before")
+    d._play_sound("device-removed")
+    assert plays == [], "no cue should play when audio cues are disabled"
+
+    d.cfg.sounds_enabled = True
+    d._play_cue("before")
+    d._play_sound("device-removed")
+    assert len(plays) == 2, "cues should play when enabled"
+
+
 def test_wakeword_while_busy_does_not_notify(monkeypatch):
     """The away-from-keyboard "Busy" storm: a detection arriving while the
     previous clip is still being processed must be ignored silently."""