Why is Personal Voice on my iPhone turning on by itself?

Re: Personal Voice : Why is it turning on by itself

Seems it is set-up, so is in use by default .. you can tap to select other voices.

or

you can triple-click the side or top button to access it: (or use the accessibility shortcut)

If needed, you can: Go to: Settings > Accessibility > Live Speech where you can tap to turn it on or off

If you haven't already viewed it ; The second-part of the video below (at 2.58) explains more about how to use it.

https://www.youtube.com/watch?v=cRXswd7yaRk