https://askubuntu.com/questions/125367/enabling-mic-mute-button-and-light-on-lenovo-thinkpads
This is what I did to fix the mic mute button on the Thinkpad T510i. The LED on it works now too. If you have a different Thinkpad, I suggest following the full tutorial on the AskUbuntu link above.
Anyways, this is what I did:
Created the file /etc/acpi/events/lenovo-mutemic
with the contents:
event=button/f20 F20 00000080 00000000 K
action=/etc/acpi/lenovo-mutemic.sh
Created the file /etc/acpi/lenovo-mutemic.sh
with the contents:
#!/bin/bash
INPUT_DEVICE="'Capture'"
YOUR_USERNAME="username"
if amixer sget $INPUT_DEVICE,0 | grep '\[on\]' ; then
amixer sset $INPUT_DEVICE,0 toggle
#echo "0 blink" > /proc/acpi/ibm/led
su $YOUR_USERNAME -c 'DISPLAY=":0.0" notify-send -t 50 \
-i microphone-sensitivity-muted-symbolic "Mic MUTED"'
else
amixer sset $INPUT_DEVICE,0 toggle
su $YOUR_USERNAME -c 'DISPLAY=":0.0" notify-send -t 50 \
-i microphone-sensitivity-high-symbolic "Mic ON"'
echo "0 on" > /proc/acpi/ibm/led
fi
Important: Replace username with your Linux username.
Find your Linux username by typing "whoami" in the terminal.
Finally, I did this:
sudo chmod +x /etc/acpi/lenovo-mutemic.sh
sudo service acpid restart
Thank you random user on AskUbuntu!