Hi there Bella7523,
Thanks for reaching out to the Apple Support Communities. Just to confirm, are you having issues with Hey Siri not working as expected? If so, give the steps listed in the resource below a try that can help with troubleshooting this specific issue: If "Hey Siri" isn't working on your iPhone - Apple Support
Check if "Hey Siri" is turned on
1. Go to Settings.
2. Tap Siri & Search.
3. From here, make sure the following settings are turned on:
- Listen for "Hey Siri"
- Allow Siri When Locked
Set up Siri to recognize your voice
1. Go to Settings.
2. Tap Siri & Search.
3. Turn off Listen for "Hey Siri," then turn it back on.
4. When the Set Up "Hey Siri" screen appears, tap Continue.
5. Say each command that you see on your screen.
6. Tap Done.
If Siri stops responding
1. Go to Settings.
2. Tap Siri & Search.
3. Tap Siri Responses.
4. Tap Prefer Spoken Responses to hear Siri speak responses, even when Silent mode is turned on.
Get more help with Siri
- Is the wrong device responding to "Hey Siri?" Learn how "Hey Siri" works with multiple devices.
- Learn how to change the volume of Siri's voice.
- If Siri activates when you press the side or Home button, but doesn't activate when you say "Hey Siri," contact Apple Support.
As for issues with contacts not being able to hear you while on a phone call, give the steps in this next resource a try that can help with troubleshooting that issue further: If the microphones on your iPhone aren't working - Apple Support
Keep us updated on the results.
Take care!