Workflow does not finish when initiated by dictation command

Try:

on run {input, parameters}
    set myPassword to "My Password"

    ignoring application responses
        do shell script "sudo killall coreaudiod" password myPassword with administrator privileges
    end ignoring
end run

OR

on run {input, parameters}
    set myPassword to "My Password"

    ignoring application responses
        do shell script "sudo killall coreaudiod &>/dev/null &" password myPassword with administrator privileges
    end ignoring
end run

This is a working example that I derived from the example in https://code.google.com/p/iterm2/wiki/AppleScript

Check out the comment from stefan.v...@gmail.com

tell application "iTerm"
    activate

    try
        set _session to current session of current terminal
    on error
        set _term to (make new terminal)
        tell _term
            launch session "Default"
            set _session to current session
        end tell
    end try

    tell _session
        write text "ls"
    end tell
end tell