voice memos not record

Do you have this problem just in voice memo?

There are 3 microphones in the iPhone.

• The bottom microphones is for Voice Memo and phone calls. (so is possible to be the lightning connector assembly - iPhone 8 Lightning Connector Assembly)
• The (top) front microphone is used for FaceTime calls, Siri and selfie videos with the front camera.
• The (top) back microphone is used for videos with the rear camera .
•  If the issue affects more than one microphone, then it could be the Audio Codec IC on the logic board. Anything at the logic board level will require micro-soldering so you would need to find a repair shop that offers those services.