How to enable the Thinkpad microphone mute key on Ubuntu 16.04
While the hardware mute button of my Lenovo x230 worked on Ubuntu 14.04 out of the box, it does not on Ubuntu 16.04. It is fairly simple to fix, though.
There is an extensive answer on Ask Ubuntu, but only part of it was required for me. Here is the gist of it.
Open a terminal
acpi_listenand press the mute key. You should see something like this:Copy
button/f20 F20 00000080 00000000 K
amixer scontrols. You will see multiple lines, one of which should be:Copy
Simple mixer control 'Capture',0
If there is no
'Capture', you might see
'Internal Mic'or similar.
Now bind the key to toggle that device. Create an ACPI event file for that:Copy
sudo vim /etc/acpi/events/lenovo-mutemic
Add the following. Fill in
acpi_listenresult for your hardware mute key. If there was no
Capturecontrol for you, change accordingly (keep the quotes).Copy
event=button/f20 F20 00000080 00000000 K action=/usr/bin/amixer sset 'Capture',0 toggle
Restart the ACPI service.Copy
sudo service acpid restart
That should be all. Do some testing to see if it actually works.
On my x230, the hardware key has an integrated notification LED. If your Thinkpad does not have that, you could use your power LED and/or an extra notification bubble.
Please see the answer on askubuntu.com on how to add such features, or if you run into trouble.