Greetings, Sammy_2313.
Welcome to the Apple Support Communities. I understand that you are unable to hear others and they are unable to hear you while on a call. Being able to hear others and be heard is vital, so I can understand your concern. I’m happy to lend a hand.
To start, I suggest that you follow the steps shown, here: If you can't hear a person on a call or voicemail or if the sound isn't clear on your iPhone - Apple Support
Also, since others can’t hear you, work through these steps: If the microphones on your iPhone, iPad, and iPod touch aren't working - Apple Support
If the issue persists, make sure to contact your carrier to ensure that you don’t have a network problem. If all is well with your network, then I suggest that you Contact - Official Apple Support.
Best wishes.