Disable microphone?

jnojr · 11-28-2012, 04:58 PM

We have several Macs in a lab where the microphone must be disabled. Not turned down, not oops I launched XYZ and it magically turned on again, not well the output isn't stored anywhere... it has to not work, and it has to not start working. Obviously, cracking open the case with little wire cutters or a soldering iron is a little extreme :-)

With some of the older Macs or versions of OS X, someone had identified kernel extensions that drove the mic and removed them, and some of the maintenance scripts check for those kexts reappearing after updates and move them again. This is less than optimal, as it's possible an update might be applied and then the script either isn't run or bombs out, and the mic is left active. That's unacceptable.

On some of the newer Macs, I was told that one kext drove both the microphone and the speakers, and they'd like to keep the speakers working. So I've been poking around a little.

On my iMac running 10.7.5, I can:

osascript -e "set volume input volume 0 --mute"

However, running a similar command or just grabbing the slider can turn it back up again. I'd like to find a way to "lock" that, or grey it out, at least for unprivileged users, but something that permanently lobotomizes it would be fine too. I was poking around in /System/Library/PreferencePanes/Sound.prefPane/ but there's nothing I can identify as the appropriate setting or file.

acme.mail.order · 11-28-2012, 06:35 PM

You are fighting a core function of the operating system, and I suspect that the input and output are in the same package.

Since it appears to be extremely important to you to have no microphones, then I recommend the extreme method you mentioned - open the case and disconnect it. Depending on which model you have the microphone could be on the same connector as other things which would require clipping it off rather than unplugging it - don't short the wires out, and of course this voids your warranty.

Out of curiosity, what do you do in this lab?

chabig · 11-28-2012, 11:28 PM

Quote:

Originally Posted by jnojr


	However, running a similar command or just grabbing the slider can turn it back up again. I'd like to find a way to "lock" that, or grey it out, at least for unprivileged users, but something that permanently lobotomizes it would be fine too.

You can use Parental Controls to prevent use of System Preferences. That might do the trick.

benwiggy · 11-29-2012, 02:56 AM

If the model(s) of Mac have an audio in socket, then all you have to do is select the Line-in as in the input source in Sound Preferences, and make sure that the preferences are locked from non-admins.

acme.mail.order · 11-29-2012, 09:00 AM

On my machine, regular users can change audio settings including input source.

And that only works until someone plugs a mic in - he seems to want it off for good.

11-28-2012, 04:58 PM	#1
jnojr Registered User Join Date: Nov 2012 Posts: 1	Disable microphone? We have several Macs in a lab where the microphone must be disabled. Not turned down, not oops I launched XYZ and it magically turned on again, not well the output isn't stored anywhere... it has to not work, and it has to not start working. Obviously, cracking open the case with little wire cutters or a soldering iron is a little extreme :-) With some of the older Macs or versions of OS X, someone had identified kernel extensions that drove the mic and removed them, and some of the maintenance scripts check for those kexts reappearing after updates and move them again. This is less than optimal, as it's possible an update might be applied and then the script either isn't run or bombs out, and the mic is left active. That's unacceptable. On some of the newer Macs, I was told that one kext drove both the microphone and the speakers, and they'd like to keep the speakers working. So I've been poking around a little. On my iMac running 10.7.5, I can: osascript -e "set volume input volume 0 --mute" However, running a similar command or just grabbing the slider can turn it back up again. I'd like to find a way to "lock" that, or grey it out, at least for unprivileged users, but something that permanently lobotomizes it would be fine too. I was poking around in /System/Library/PreferencePanes/Sound.prefPane/ but there's nothing I can identify as the appropriate setting or file.

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11-28-2012, 06:35 PM	#2
acme.mail.order League Commissioner Join Date: Sep 2003 Location: Tokyo Posts: 6,045	You are fighting a core function of the operating system, and I suspect that the input and output are in the same package. Since it appears to be extremely important to you to have no microphones, then I recommend the extreme method you mentioned - open the case and disconnect it. Depending on which model you have the microphone could be on the same connector as other things which would require clipping it off rather than unplugging it - don't short the wires out, and of course this voids your warranty. Out of curiosity, what do you do in this lab?

11-29-2012, 02:56 AM	#4
benwiggy League Commissioner Join Date: Aug 2006 Posts: 5,039	If the model(s) of Mac have an audio in socket, then all you have to do is select the Line-in as in the input source in Sound Preferences, and make sure that the preferences are locked from non-admins.

11-29-2012, 09:00 AM	#5
acme.mail.order League Commissioner Join Date: Sep 2003 Location: Tokyo Posts: 6,045	On my machine, regular users can change audio settings including input source. And that only works until someone plugs a mic in - he seems to want it off for good.