metrovoc/README.md

## README.md

      
    Raw
  

              README.md
            
          
    macOS Tahoe Audio Glitch: Diagnosis & Workaround

Symptom

On macOS Tahoe (26.x, tested on 26.3 / M3 MacBook Air), system audio gradually degrades over time — volume drops significantly and sound becomes muffled across all outputs (built-in speakers, Bluetooth headphones, etc.) at the same volume setting.

Onset is intermittent: anywhere from hours to days after a clean reboot.
coreaudiod sometimes shows elevated CPU usage during the degraded state.
A full reboot reliably restores normal audio. The issue then eventually recurs.

What doesn't work


sudo killall coreaudiod: Does not resolve the issue. In my experience, each restart of coreaudiod appeared to make the CPU usage slightly worse, suggesting the problem compounds with repeated restarts.
Toggling sample rate (48000 ↔ 44100 via Audio MIDI Setup): No effect in my case.
pmset sleepnow (sleep/wake cycle): Did not help either.

Key observation

When I killed all audio daemon processes (coreaudiod, audiomxd, audioclocksyncd, etc.) without killing audio client processes first, the audio would recover for approximately 1 second before immediately degrading again. This strongly suggests that one or more audio client processes hold some corrupted state that gets re-applied to the freshly restarted audio stack.
When I killed all processes using CoreAudio (clients + daemons together), audio recovered and remained normal.
What works

Kill all CoreAudio client processes first, then restart all audio daemons:
# 1. Find and kill all user processes that have CoreAudio loaded
lsof 2>/dev/null | grep CoreAudio | awk '{print $2}' | sort -un | xargs kill -9 2>/dev/null

# 2. Kill Xcode/CoreSimulator if running (known to exacerbate the issue)
killall Xcode SimulatorTrampoline com.apple.CoreSimulator.CoreSimulatorService simdiskimaged 2>/dev/null

# 3. Restart all audio daemons (not just coreaudiod)
sudo killall -9 coreaudiod audiomxd audioclocksyncd audioanalyticsd audioaccessoryd AudioComponentRegistrar
See fixaudio.sh for a ready-to-use shell function.
Environment & possible contributing factors

These may or may not be relevant — listed for completeness:

macOS Tahoe 26.3 (25D125), Apple M3 MacBook Air
Data migrated between machines (Air M3 → Pro M4 Pro → back to Air M3). Migration left behind ghost audio device entries (BlackHole, Zoom virtual device, old Bluetooth devices) in /Library/Preferences/Audio/com.apple.audio.SystemSettings.plist.
Bluetooth headphones (Bose QC Ultra 2 HP) frequently connected/disconnected.
Xcode and CoreSimulator services running in the background. Multiple community reports indicate Xcode/Simulator can amplify Tahoe audio issues.

Status

This is a workaround, not a root fix. The underlying cause appears to be a bug in macOS Tahoe's CoreAudio stack. Apple has reportedly addressed some audio issues in 26.1, but the problem persists through 26.3 in my environment.
I have not yet identified which specific client app is the primary culprit. The watchdog is running and I'll update this if I find out.

  
## fixaudio.sh
#!/bin/bash
# fixaudio — workaround for macOS Tahoe audio degradation bug
# Kills all CoreAudio clients + all audio daemons to restore normal audio.
#
# Usage: source this file and run `fixaudio`, or add the function to your .zshrc/.bashrc.
# Requires sudo for killing system audio daemons.

fixaudio() {
  sudo -v || return 1

  local skip="coreaudiod|audiomxd|audioclocksyncd|audioanalyticsd|audioaccessoryd|AudioComponentRegistrar|audio.DriverHelper|audio.SandboxHelper|ParrotAudioPlugin"

  echo "=== Audio clients ==="
  lsof 2>/dev/null | grep CoreAudio | awk '{print $2, $1}' | sort -t' ' -k1,1 -un | grep -vE "$skip" | while read pid name; do
    echo "  kill $name ($pid)"
    kill -9 "$pid" 2>/dev/null
  done

  killall Xcode SimulatorTrampoline com.apple.CoreSimulator.CoreSimulatorService simdiskimaged 2>/dev/null

  sleep 1
  echo "=== Audio daemons ==="
  sudo killall -9 coreaudiod audiomxd audioclocksyncd audioanalyticsd audioaccessoryd AudioComponentRegistrar 2>/dev/null
  echo "  killed all audio daemons"

  sleep 2
  echo "=== Done. coreaudiod PID: $(pgrep coreaudiod) ==="
}
	#!/bin/bash
	# fixaudio — workaround for macOS Tahoe audio degradation bug
	# Kills all CoreAudio clients + all audio daemons to restore normal audio.
	#
	# Usage: source this file and run `fixaudio`, or add the function to your .zshrc/.bashrc.
	# Requires sudo for killing system audio daemons.

	fixaudio() {
	sudo -v \|\| return 1

	local skip="coreaudiod\|audiomxd\|audioclocksyncd\|audioanalyticsd\|audioaccessoryd\|AudioComponentRegistrar\|audio.DriverHelper\|audio.SandboxHelper\|ParrotAudioPlugin"

	echo "=== Audio clients ==="
	lsof 2>/dev/null \| grep CoreAudio \| awk '{print $2, $1}' \| sort -t' ' -k1,1 -un \| grep -vE "$skip" \| while read pid name; do
	echo " kill $name ($pid)"
	kill -9 "$pid" 2>/dev/null
	done

	killall Xcode SimulatorTrampoline com.apple.CoreSimulator.CoreSimulatorService simdiskimaged 2>/dev/null

	sleep 1
	echo "=== Audio daemons ==="
	sudo killall -9 coreaudiod audiomxd audioclocksyncd audioanalyticsd audioaccessoryd AudioComponentRegistrar 2>/dev/null
	echo " killed all audio daemons"

	sleep 2
	echo "=== Done. coreaudiod PID: $(pgrep coreaudiod) ==="
	}
No results found