Hi Aretha, you don't actually have to change the numbers in your phone to dial by voice command. Do you see the transparent bar near the top of your screen with Google written across it? There's a mic icon on the right side of this bar, just tap on it once and say, "Call [contact name]."
For example, I could do this:
1. Tap on the mic button
2. Say, "Call Aretha"
Afterwards, a call will be placed automatically to the person named Aretha on my phonebook. If you do this on your own and it doesn't happen automatically, the screen may show you instructions on how to proceed. Just follow these and you'll be good to go.
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