Use Data Only on LTE
Cellular Data Enable LTE Off or Data Only
When making phone calls on your iPhone do your callers complain about your voice being distant or muted? Does your speaker sound ok but your normal microphone sound horrible?
Many blogs claim this is a hardware issue and you should fix or upgrade your phone. However, this is not true and probably a scam to get you to upgrade your phone. Here is how to fix the problem disabling a voice over LTE on your phone.
We discovered through the help of Apple tech support that using data only over Enable LTE helps improve audio call quality. For some reason voice over LTE might not work well on iPhone 5, 7, 8 and even new models.
Here is how to test if turning off VOLTE will help improve your call quality.
1) Test your microphone with the voice memo app on your phone
2) Go to cellular data and turn on data only on Enable LTE
3) Test a voice call and test a Facetime audio only call.
This should help you fix your voice quality on your phone without having to upgrade to a new phone.
According the the Apple tech support person this LTE voice problem happens with all carriers.