People can't hear me when I call them

Hi K_99,

Thanks for coming to Apple Support Communities for help today.

Have you tried testing the mic with the Voice Memos app: If the microphones on your iPhone aren't working?

"If people can't hear you on phone or FaceTime calls

1. Open the Voice Memos app. 
2. Tap the Record button , speak at the bottom of your phone, then stop the recording. 
3. When you play back the memo, you should hear your voice clearly.
4. If you don't hear your voice clearly, contact Apple Support."

Also be sure your receiver is clean and not blocked: If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker.

"Clean your receivers and speakers

Remove all screen protectors, films, or cases from your device. Check the speaker opening to see if it's blocked or dirty. On iPhone only, make sure that the receiver is not blocked or dirty. If necessary, clean the speaker or receiver opening with a small, soft-bristled brush. Make sure that the brush is clean and dry."

If the issue still isn't resolved after these steps, it's likely that the iPhone will require service.

Have a fantastic day!