Toggle mic mute on OSX

toggle-mic-mute.applescript

-- Thanks to:
-- https://coolaj86.com/articles/how-to-control-os-x-system-volume-with-applescript/
-- https://robservatory.com/silently-mute-the-mic-input-via-applescript/
-- https://macscripter.net/viewtopic.php?id=16588
--
-- For integration with the system see: http://eddmann.com/posts/creating-a-mac-microphone-mute-keyboard-shortcut/
--
-- In order to keep the `storedInputLevel` value you need to use it compiled:
-- $ osacompile -o toggle-mic.scpt toggle-mic.applescript
-- And then run:
-- $ osascript toggle-mic.scpt

property storedInputLevel : missing value

if input volume of (get volume settings) is 0 then
    -- we're muted, so it's time to unmute

    -- get the saved input level, and restore it
    set volume input volume storedInputLevel
else
    -- we're unmuted, so it's time to mute

    tell application "System Events"
        -- save the current input volume setting --
         set storedInputLevel to input volume of (get volume settings)
    end tell

    -- mute the input
    set volume input volume 0
end if

input volume of (get volume settings) ,the return value maybe missing value