Listen to the default microphone
gst-launch-1.0 pulsesrc ! autoaudiosinkSpecify the source by name (can match a substring)
gst-launch-1.0 pulsesrc device="device_name" ! autoaudiosinkRecord the monitor of the default sink
gst-launch-1.0 pulsesrc device=@DEFAULT_MONITOR@ ! opusenc ! oggmux ! filesink location=path/to/file.ogg