Mac OS X Lion: Sound problem after unplugging my headset/headphones.

Make sure that "All Processes" is selected in Activity Monitor. I believe the default is "My Processes", which won't show you system daemons.

The little kill coreaudio kill app worked great.

I hope Apple takes note and fixes this glitch in a coming update.

Thanks a bunch Ken.

I also thought i was the only one having this problem and it is annoying. I am not going to go through contacting this person and that person for something apple has created with their upgrading their system. I feel that apple needs to come up with some answers and some type of fix because it does not make sense to have to reboot in order to get sound. That is a great big problem and inconveyance on so many levels. Apple needs to get it together since too many people invest in their products...

I have an advanced version of this glitch 🙂

I use my MB (old black one) to watch videos on tv. I connect audio thru optical cable. Before Lion all was fine. Now there is no sound when watching AVI files. Others, like MKV, MP4 seem to play (the sound) ok. I tried switching to conventional minijack to RCA and the sound was gone altogheter. Only after reboot i got it back.

So now to watch AVIs i have to plug in minijack to RCA; when watching MKVs, i can use optical. But i have to choose first whitch one i'm going to watch, because after switching, the sound will be lost at all.

Lets hope Apple can hear us an fix this (and quite a few other) Lion glitches 🙂

(in case you wonder if sound channels and/or encoding differ - it doesn't matter, because in Snow Leopard and Leopard all was fine. Its a Lion glitch)

I have an early 2011 13' MBP and as soon as I installed Lion my headphones quit working. I tried the fix by changing the settings In the Audio MIDI Setup and it didn't work for me. They are Shure se535 and I use them everyday with my Iphone so I know its not them. Hope there is an update soon to fix this, pretty big screw up iof you ask me, Apple.

Hi Guys,

I am experiencing a similar problem on iMac Mid 2011. After install the Lion I had problems to use the sound.

I have a usb video capture device which also allows sound capture.

I solved sound problem disconnecting this usb device during computer startup. I guess OS Lion had some problem during driver load of sound cards...

Any idea how get this solved?

I am also having this problem. It is a real pain. The ultimate irony is that my headphones and audio work like a charm on my Windows 7 bootcamp side.

Ken's command didn't work for me. I would appreciate any other suggestions, although I'm guessing we have to wait for an update from apple.

I have this same problem after unplugging speakers that I have been using for a month with no problem. Now, no internal sound except the chime. I am using Leopard.

The volume control in the upper toolbar has the ball all the way at the top but it is greyed out and not moveable. Nothing in sound preferences is changeable to help this. When I push the volume control F4 or F5 or mute they all have a circle with a line through it showing that there is no sound. Resetting PRAM didn't help and I went into MIDI utility as someone else suggested and mute was not checked in the boxes there, though next to M the sound is turned all the way down but it is greyed out there too and I can't change it. I tried the SMS reset too and that did not help either. ???

And I assume the app will not work with Leopard.

Thanks. I did the Activity Monitor procedure and restarted (and did PRAM reset again just for good measure on restart) and no change. I wonder if I should do it with the external speakers plugged in, as someone mentioned above. I'm not where they are today, though.

OK, I got back to my office where the speakers are, plugged them in and the sound volume control became black and moveable again. But when I unplugged them it went back to gray. So I plugged them back in and ran the Activity Monitor process as you suggested and it worked. Even when I restart now, it is usable again. If it goes back to gray in the future, I will run the app. THANK YOU kyen99!

I've just upgraded from a white MacBook to a 13" i7 MacBook Pro that came with OSX Lion. I've had it just over 3 weeks and I've always had this problem. I'm a student so spend most of my day working with headphones, but of an evening when I want to watch films using my internal speakers this happens. It also happens during the day if I remove and re-plug the headphones more than x times (about 5). It's really inconvenient having to reboot, and I don't have the problem caused by X11 because I'd never even heard of it before reading this thread.

Also, my iTunes won't quite unless forcequite, I don't know if this is related?

Any advice on what I should do as it's inconveniencing my life tremendously.

For reference, all my hardware is Mac compatible as my headphones are Beats Pros.

Thank you.

Here's another goodie from the Lion audio failfest. I'm streaming my audio from a mid 2010 MacBook Pro (17'') to a Logitech bluetooth adapter my speakers are connected to. With some trickery I got this setup to a point where it chose to work reliably, more or less. Some days ago I used my Samsung bluetooth headphones on said machine, only to see all of my audio deeply frozen - to a point I had to dance the nuke-your-whole-Lion-BT-scheme-and-rebuild-from-scratch-dance. Brilliant. Now all is back to good working order - except the volume control for said Logitech device. Increasing or decreasing volume (method doesn't matter) will invariably kill sound alltogether, which can be brought back instantly by tapping the mute button on the keybord twice. Feels almost kinda … playful. Did I mention that Logitech thingie works like a charm from my original iPad, volume and all?

This Lion audio problem is driving me nuts. None of the solutions proposed here or in any other thread in this forum has worked for me. What was working until today was running all the automation scripts with Onyx. But today this solution stopped working too (yesterday's update related, maybe).

Well, what makes me really angry is that I don't see Apple say a word about this. Looks like they're not even looking at it.