Hi PastaKathy,
If you suspect a problem with your device microphone, check out If the microphones on your iPhone aren't working for some steps to isolate the concern:
"Clear the microphones
- Remove any screen protectors, films, or cases from your iPhone.
- Clear any debris from the openings of your iPhone."
and
"If people can't hear you on phone or FaceTime calls
- Open the Voice Memos app.
- Tap the Record button , speak at the bottom of your phone, then stop the recording.
- When you play back the memo, you should hear your voice clearly.
If people can't hear you when you're using speakerphone
- Open the Camera app.
- Record a video while speaking at the top of your iPhone.
- Tap the camera chooser to switch to the other camera. Then record another video while speaking at the top of your iPhone.
- When you play back the videos, you should hear your voice clearly."
You can also test using paired or connected headphones that include a microphone. If those work and the other steps do not help, service is likely required and consulting Apple Support will be next.
Regards.