Many iPhone X users are facing issue with ear speaker that iPhone X users while attempting to make a call, The person on the other end can hear but I can't hear them. Calls on the speaker works fine but its issue with iPhone X earspeaker only. Restarting and resetting the iPhone does not seems to fix the issue. The issue is even reported with brand new 1 day old iPhone X.
Not only the iPhone X some iPhone 8 users are facing issue of no audio or very low earpiece volume in iOS 11. This is defiantly an issue with iPhones that Apple should focus upon.
Fix 1: Turn off Bluetooth
For some user just by turning off Bluetooth while making calls fixed the issue. So please try to keep the iPhone’s Bluetooth off and check for any improvements.
Fix 2: hard reboot
Hard reboot your iPhone X: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Then, press and hold the Side button until you see the Apple logo.
However this seems to fix the issue but temporarily and may occur again.
Fix 3: Turn off Noise cancellation
Go to Settings from your home screen
Tap General, then go to Accessibility
Scroll all the way down to the Hearing section
Turn off ‘Noise Cancellation’
Fix 4: Repair the Ear Speaker or Replacement from Apple
There are likely chances that your iPhone has hardware defect and needs to be repaired. You should get it to nearby Apple store to get it checked and receive other iPhone in place of defective unit.