Siri does not answer me when I say Hey Siri

This might help, If "Hey Siri" isn't working on your iPhone - Apple Support

I hope this helps!

Pastorjdj wrote:

Siri does not answer me when I say Hey Siri. Siri would respond with yes.

What has possibly changed?

Did you recently switch to a newer phone? On the newer model phones, Siri doesn't say "yes". You don't need to leave any pause between "Hey, Siri...." and your question. You just say, "Hey, Siri, what time is it?".