I had a request from a customer who saw that our TalkBox had an external mute input.
They were tired of listening to the special STIPA signal through their public address system even when they were not actively taking speech intelligibility measurements with their XL2.
We purchase a 3G Gate Opener on Amazon and a pay-as-you-go SIM card from Mint.
We cut a 3.5 mm to 3.5 mm cable to go from the TalkBox's 3.5 mm to the Gate Opener Terminal strip.
We downloaded the Android App (also available on iOS) and got it running.
Here is a link to some screen shots going through the setup
If you are interested in seeing it in action, stop by our booth at InfoComm, Booth C1167.