如果 Ubuntu 21.04 在插入 USB 麥克風的情況下運行，pulseaudio 無法啟動。但是如果Ubuntu 21.04在沒有USB的情況下運行，pulseaudio可以正常啟動，並且即使在系統啟動後插入USB仍然可以正常工作。
當pulseaudio啟動失敗時來自journalctl的日誌訊息：
-- Boot 37de7028dfda47569d03504658160650 --
Dec 11 04:46:09 hirsute-server systemd[1958]: Starting Sound Service...
Dec 11 04:46:10 hirsute-server pulseaudio[1967]: No such profile: output:hdmi-stereo
Dec 11 04:46:10 hirsute-server pulseaudio[1967]: Failed to initialize daemon due to errors while executing startup commands. Source of commands: /etc/pulse/>
Dec 11 04:46:10 hirsute-server systemd[1958]: pulseaudio.service: Main process exited, code=exited, status=1/FAILURE
Dec 11 04:46:10 hirsute-server systemd[1958]: pulseaudio.service: Failed with result 'exit-code'.
Dec 11 04:46:10 hirsute-server systemd[1958]: Failed to start Sound Service.
Dec 11 04:46:10 hirsute-server systemd[1958]: pulseaudio.service: Scheduled restart job, restart counter is at 1.
Dec 11 04:46:10 hirsute-server systemd[1958]: Stopped Sound Service.
Dec 11 04:46:10 hirsute-server systemd[1958]: Starting Sound Service...
Dec 11 04:46:11 hirsute-server pulseaudio[2087]: No such profile: output:hdmi-stereo
Dec 11 04:46:11 hirsute-server pulseaudio[2087]: Failed to initialize daemon due to errors while executing startup commands. Source of commands: /etc/pulse/>
Dec 11 04:46:11 hirsute-server systemd[1958]: pulseaudio.service: Main process exited, code=exited, status=1/FAILURE
Dec 11 04:46:11 hirsute-server systemd[1958]: pulseaudio.service: Failed with result 'exit-code'.
Dec 11 04:46:11 hirsute-server systemd[1958]: Failed to start Sound Service.
Dec 11 04:46:11 hirsute-server systemd[1958]: pulseaudio.service: Scheduled restart job, restart counter is at 2.
有任何想法嗎？如果需要更多信息，請隨時告訴我。