On the Android box, go to into the Google Play store and download and install "Speech Recognition and Synthesis from Google"
Once installed, exit the Google Play store and go to
Settings > Device Preferences > Accessibility > Text to Speech > Language. In here, set to English (UK)
then in almost the same menu (back 1 from setting Language) go into
Settings > Device Preferences > Accessibility > Text to Speech > Settings for Speech recognition and synthesis from Google. Make sure this has a dot to be selected for the software to turn text into speech.
From a PC/web browser go to https://lt.engage.gp
Click on the 3 lines in the top right and choose Management console.
Expand "Patient Call" from the left side menu
Under Waiting Room TV, choose TV1 in the main window and then tick the box for Announce Call Messages and press Save