Signal to cause mate-panel to refresh icons

I implemented a script that acts like a toggle and added it as an application shortcut to mate-panel. All it does essentially is touch or remove a file that other applications interrogate. I have processes that speak text through my speakers like saying when I get an email it reads the sender and subject line. Sometimes when I'm on the phone or something like that I want it to be silent - hence the script that touches a file. The script also changes the icon used in mate-panel.


# This just toggles the creation of the /opt/clearscm/bin/shh file
if [ -f $touchfile ]; then
  rm $touchfile
  cp ~/.icons/ShhOff.png ~/.icons/Shh.png
  # Stop currently playing audio
  killall play
  # Stop any Google TTS
  kill -9 $(cat /tmp/
  # Clean up tmp
  rm -rf /tmp/simple_google_tts.*
  # Touch shh file
  touch $touchfile
  # Change the icon
  cp ~/.icons/ShhOn.png ~/.icons/Shh.png

Under gnome-panel the change of the icon file would be sensed and re-drawn in the panel. It was a good way for me to know if the sound was on or off.

mate-panel doesn't do this. I was hoping that perhaps I could send mate-panel a signal to refresh the icons.