Load sound in function

[ag288]

I'm basically trying to implement a medical token display system. When a certain token is called, the token number should be read out loud. However, since this is a wall mounted display screen, the sound has to be played without any user interaction. However, the speak() function only triggers on button click. Is there some way of triggering the sound from a function (without user interaction). I tried a hidden button click but that's not working either