The Silent Microphone
Ubuntu utilizes the PulseAudio (or more recently, PipeWire) sound server to manage audio inputs and outputs. A common and highly frustrating issue occurs when the system resumes from a Suspend (sleep) state. Upon waking up, Ubuntu sometimes fails to properly restore the audio state and automatically mutes the primary microphone, or drops its input volume to zero. This means that if you wake your laptop to immediately join a Zoom or Microsoft Teams meeting, you will be completely inaudible to the other participants until you manually dig into the system settings to unmute yourself.
Forcing Audio State Restoration
To ensure your microphone is always ready and stop Ubuntu from automatically muting your audio input upon waking from suspend, you must adjust the ALSA (Advanced Linux Sound Architecture) state daemon.
The issue usually stems from the ALSA restore service failing to apply saved volume levels after a power state change. Open a terminal (Ctrl+Alt+T). First, manually set your microphone to the correct, unmuted level using the standard Ubuntu Sound settings. Then, in the terminal, type sudo alsactl store and press Enter (provide your password). This forces ALSA to save the current, working configuration. Next, you need to ensure the restore service is enabled to run automatically. Type sudo systemctl enable alsa-restore.service. If the problem persists, it may be a conflict with PulseAudio’s module. You can try disabling device restoration in PulseAudio by editing its config: sudo nano /etc/pulse/default.pa, finding the line load-module module-device-restore, and commenting it out by placing a # at the start of the line. Restart PulseAudio (pulseaudio -k) to apply.