How do I change the 'mm hmm' response after saying 'Hey Siri' on an updated iPhone?

H1290 is completely correct. If you wake Siri, then pause, all Siri is doing is letting you know you were heard and Siri is waiting for your response. It would be no different, if you called me name and then didn't say something as I can assure I might not be as polite as saying Uh Huh. Nope, I might say "WHAT?" if you didn't say anything after calling my name.

As H1290 suggests, don't pause. Just say "Hey Siri what's the temperature outside?" As opposed to, "Hey Siri...............what's the temperature outside?"

Hello!

Thats just a prompt to get you to continue talking. Say “Hey Siri” or “Siri”, and continue with your request. Don’t pause after saying it’s name.

Also, you shouldn’t consider Siri to be rude. It’s just a computer talking. Incapable of feelings or emotions.

Have a great day!