Hi Noperooskies,
It sounds like you are experiencing issues with the microphones on your iPhone. We can help with this.
Do you experience issues with the microphone with every phone call you make or does the issue only occur when you are in certain locations? Are you able to put the call on speakerphone or is the option greyed out once you are on the call?
Do you notice a difference if you restart your iPhone? You can find out more information about how to restart your iPhone here: Restart your iPhone
Is your iPhone up-to-date with the latest version of iOS? You can find out more information about updating your iPhone here: Update your iPhone, iPad, or iPod touch
We look forward to hearing back from you!