Which Siri?

I carry my iPad with me everywhere. When I'm reading a book, I like the fact that phone calls go to my iPad instead of my iPhone.

But in the car, with my iPhone mounted over my air conditioner, when I say "Hey Siri", I want my phone to answer (I do this to use its GPS). I guess I should just use my fingers to start Siri. Is there a better way?

Thanks.

If you have "Hey Siri" enabled on both the iPhone and iPad and speak that magic incantation, both the iDevices might respond, only one of them might respond or nether of them will. There is no way of controlling (unless you are REALLY adept at directing your voice in a very unusual and inhuman way toward a specific iDevice) which device will respond. You don't need to have "Hey Siri" enabled on the iPad for the phone forwarding, so you might want to disable it..