Hearing

Hello Helprequiredasap,

Thank you for reaching out to Apple Support Communities.

These steps should help troubleshoot your microphone issues:

"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.

If people can't hear you when you're using speakerphone 

1. Open the Camera app.
2. Record a video while speaking at the top of your iPhone.
3. Tap the camera chooser  to switch to the other camera. Then record another video while speaking at the top of your iPhone.
4. When you play back the videos, you should hear your voice clearly."

More details can be found here: If the microphones on your iPhone aren't working

If the issue persist, can you provide a few more details? When did you first notice this? Does this happen with multiple apps? Also, what is your exact iOS version?

Cheers!