Command to mute and unmute a microphone

You can mute with:

/usr/bin/amixer -q -c 0 sset 'Master',0 mute

Unmute:

/usr/bin/amixer -q -c 0 sset 'Master',0 unmute

You just need to replace ‘Master’ with the appropriate mixer name, on the terminal use “amixer” to get a list of mixer devices.

About setting the keyboard shortcut check the answers for How can I find which command is bound to a given keyboard shortcut?

pacmd is the command line interface to PulseAudio (the sound subsystem used in recent releases). I don’t know what the exact command is you’d need but I think you’d want to play with the set-sink-input-mute function.

pacmd is interactive when run without instructions so you have a good opportunity to play around with it and convert that into a one-line function for toggling mute.

You can mute the microphone with

amixer set Capture nocap

and unmute the microphone with

amixer set Capture cap

amixer set Capture toggle && amixer get Capture | grep '[off]' && notify-send "MIC switched OFF" || notify-send "MIC switched ON"

the gnome-shell extension nothing to say, which can be installed from its extensions.gnome.org page, provides a microphone icon, mouse and keyboard control, and walkie-talkie style push-to-talk.

Simply mute/unmute with this command:

amixer -D pulse sset Capture toggle

You can also add notification to make sure it’s on or off, as per vladimirich answer to the same question

amixer -D pulse sset Capture toggle && amixer get Capture | grep '[off]' && notify-send "MIC switched OFF" || notify-send "MIC switched ON"

Inspired by Mark Rooney’s answer on muting/unmuting sound.

To toggle mute of default microphone in pulseaudio:

1. Make sure that you have pacmd (from pulseaudio-utils package) and notify-send (from libnotify-bin).
2. Use this script:

#!/bin/sh

pacmd list-sources | awk '
BEGIN {default_found=0;}

/^[t ]**/ {default_found=1;}

/^[t ]*name:/ {
    if (default_found) {
        name=$2;
        gsub("[<>]", "", name);
    }
}

/^[t ]*muted:/ {
    if (default_found) {
        if ($2=="yes") {
            mute=0;
            icon="microphone-sensitivity-medium";
            status="unmuted"
        } else {
            mute=1;
            icon="microphone-sensitivity-muted";
            status="muted"
        }
        system("pacmd set-source-mute " name " " mute);
        system("notify-send --expire-time 1000 --icon " icon " Microphone: " status);
        exit;
    }
}

/^[t ]*index:/{if (default_found) exit;}'

Complementing the response ofLucian Adrian Grijincu and vladimirich

Add the display of a message by enabling/disabling the microphone.

Run multiple commands on the shortcut command:

$ sh -c "amixer set Capture toggle ; amixer get Capture | 
     grep '[off]' && notify-send 'MIC switched OFF' || notify-send 'MIC switched ON'"

Based on answer above https://askubuntu.com/a/337662/106182

I like to create my own terminal stupid shortcuts. So to configrure m = mute; mm = unmute

I added this to ./.bashrc

# ~/.bashrc
# 
alias m="amixer set Capture nocap"
alias mm="amixer set Capture cap"

update

interesting enough, yesterday I’ve re-enable autostart of “Screen Locker (Launch screen locker program) in the menu> sessions and startup > Application Autostart and now my hardware mute button start working (after restart) I have no idea why (XFCE Xubuntu 18.08)

I’m still keeping those terminal shortcuts but just wanted to point out

I switch between a USB webcam/mic and my internal mic and the other solutions typically work on the "default" device which is often not the device I’m actively using so I wrote this to mute all microphones

pacmd list-sources | 
        grep -oP 'index: d+' | 
        awk '{ print $2 }' | 
        xargs -I{} pactl set-source-mute {} toggle 
        && pacmd list-sources | 
        grep -oP 'muted: (?:yes|no)'

Using answer of vladimirich I created a script, because we can’t execute multiple commands in a hotkey entry.

• so I made a script with the line:

  amixer set Capture toggle && amixer get Capture | grep '[off]' && notify-send "MIC switched OFF" || notify-send "MIC switched ON"
  

• put it in a .sh file

• and call it in the hotkey command with sh <path to script.sh>.

Works like a charm.

Here’s an example for toggling a selected audio source only using CLI (command line interface) only:

1. Get list of possible sound cards in the system:

   pacmd list-sources | grep card:

   Example:

   card: 0 <alsa_card.usb-Microsoft_Microsoft___LifeCam_HD-5000-02>

   card: 1 <alsa_card.pci-0000_00_1b.0>

2. Select some way to identify the correct card. If you trust that your configuration does not change, you can use card number and simply run (e.g. if you want to control the card 1):

   pactl set-source-mute 1 toggle

   However, if you instead want to prepare for a case where e.g. your USB connected source is not always connected and you only want to mute that, you can use some way to detect it from the above output. Let’s say you want to control the LifeCam HD-5000 only. Then you could do it like this:

   pacmd list-sources | grep -P "card: d+ <[^>]*LifeCam_HD-5000[^>]*>" | awk '{print $2}' | xargs -rn1 -I_ pactl set-source-mute _ toggle

   This queries all audio sources from PulseAudio, extracts card rows that have LifeCam_HD-5000 as part of their name, uses awk to extract the second part of the row to get the card number and passes it to pactl to toggle correct source muting using xargs to put the number in correct position in the command. The -rn1 flag tells xargs to do nothing if the card number couldn’t be found.

   If you need to know the mute status for some scripting, you can do

   pacmd dump | grep -P 'set-source-mute [^ ]*LifeCam_HD-5000' | awk '{print $3}'

   which will emit yes (muted) or no (not muted).

On 20.04, I see option to set a shortcut for the same under Settings -> Keyboard Shortcuts -> Sound and Media.

There is no default key assigned though.