How to Use Automator to change a system preference

Here is an AppleScript that will do this:

tell application "System Preferences" to activate

tell application "System Preferences"

reveal anchor "input" of pane id "com.apple.preference.sound"

end tell

tell application "System Events" to tell process "System Preferences"

tell table 1 of scroll area 1 of tab group 1 of window 1

select (row 1 where value of text field 1 is "Internal microphone")

end tell

end tell

quit application "System Preferences"

You can put this into an AppleScript in AppleScript Editor (it's in Utilities), or run it in Automator.

The simplest way would be to save it as an AppleScript application and use that as a login item.

I wrote it up as a standalone AppleScript application called "InputMic" and saved it to my dropbox. You can download it here if you like: https://www.dropbox.com/sh/assrkjdvns0lj9m/RjP7Mc2HcM

You can put it in your Applications folder and set it as a Login Item in system preferences > Users & Groups.

Or drag it to the dock and then run it manually, or both. It will ask for your permission to run as an accessability item in Security & Privacy settings; just click the lock in the left corner, check the box next to InputMic, and then close the lock.

Had to change the link for the script: https://www.dropbox.com/sh/j4wm8tnrv1tb8iq/9XIExh1y57