Hi @oluwatobi ,
Can’t be heard problem
Has the phone been dropped or gotten wet at all?
Is the phone in a protective case or cover?
If so remove it from the case and check if it works OK.
Can you be heard if you use the phone in loudspeaker mode (also called hands free mode)?
Try using the earphones with the microphone attachment when on a call to prove that the phone’s voice transmission circuitry is working.
If you can be heard OK with either the earphones+microphone or in loudspeaker mode then the phone’s internal microphone may be faulty or the voice inlet hole may be blocked with lint etc.
Use a strong light and a magnifying glass to inspect the voice inlet hole located on the bottom edge of the phone to see if it is blocked at all.
If it is or even if you can’t tell, DO NOT use a pin or metal probe to clear the obstruction as you may damage the microphone which is directly behind the hole. Try using a vacuum cleaner and see if the obstruction (if any) can be sucked out.
If still no good then the phone will have to be opened and the problem further diagnosed
Since you are having other problems as well try starting the phone in safe mode and check if it works OK
To enter safe mode with the phone ON press and hold the power button. When the shutdown options window opens press and hold power off. An option will appear to reboot the phone in safe mode.
To exit safe mode turn off the phone in the normal way.
If the phone works OK when in safe mode then a downloaded app is the cause of the problem. The trick is to find out which one.
You’ll need to uninstall each downloaded app one by one and test the phone in normal mode until it works OK. When it does then the last downloaded app that was uninstalled was the culprit.
If it still doesn’t work OK when in safe mode, try wiping the cache partition in the phone and check if this resolves the problem