alsapulseaudio
I was listening to music, and my sound suddenly went dead in all my applications. I'm using Ubuntu 12.04, which uses pulseaudio, so I tried sudo /etc/init.d/pulseaudio restart, but nothing happened. According to lsof | grep pcm, nothing is using the soundcard at the moment, although I'm not entirely sure if my source for that command is applicable.
Is there a way another way to restart Ubuntu 12.04's sound system from the command line without rebooting the system?
Fixed it on my box. I think there's something wrong with pulse audio and the sound card (maybe problems with an updated driver) or maybe something with the pavucontrol application. Either way, I had to tell PulseAudio to stop looking for my sound card and just play everything through Alsa.
I ran aplay -l | grep card to find the specific sound card I wanted, then I edited /etc/pulse/default.pa and added a line load-module module-alsa-sink device=hw:0,0 where the 'hw:0,0' corresponds to the card found in the aplay -l command. Restart PulseAudio or reboot the system and give it a shot.
Note: I noticed Pulse doesn't recognize my built-in webcam or the audio at the moment either. sigh
PulseAudio basically sits atop ALSA, and use it internally. ALSA is unable by itself to be used by multiple applications, so PulseAudio provides this functionality among others.
Summarized:
This diagram is from the Wikipedia page of PulseAudio:
Best Answer
I've used
pulseaudio -k && sudo alsa force-reloada couple of times, and it worked well. The first part kills pulseaudio, the second reloads ALSA. You don't need to restart pulseaudio, because it auto-restarts.