Trigger event on focus

Interested in topic for my current project. When button gains focus, to mimic functionality of hover, would like audio to be triggered that will signify the state conditionally f the button’s state is visited. I have a. inelegant workaround that uses the previous object losing focus and a conditional statement for the button the user will be arriving on. That way they will know from an audible alert the button being read out by reader is complete. A sighted user would experience the button as grayed out. Worried about users going in an order I don’t anticipate (“up” instead of “down”). Thank you.