Hi KatRosBon,
Thanks for posting in Apple Support Communities. You've tried some great steps so far. To isolate whether this is related to your AirPods, iPhone or Phone app, let's observe the following.
• What happens when you make a phone call using only your iPhone without the AirPods?
• What happens if you make a FaceTime call with the AirPods connected?
• Is it that you cannot hear your contacts, they cannot hear you or what happens?
If this issue seems related to your AirPods and your contacts cannot hear you, try changing your microphone setting from Settings > [AirPods name]. If needed, reference the 'Set microphone to left, right, or automatic' section of Change the settings of your AirPods and AirPods Pro - Apple Support.
Next, if continued, try resetting your AirPods which can help with multiple issues including audio. Guidance below is from How to reset your AirPods and AirPods Pro - Apple Support.
1. Put your AirPods in their charging case, and close the lid.
2. Wait 30 seconds.
3. Open the lid of your charging case.
4. With your AirPods in your ears and connected to your iPhone, iPad, or iPod touch, go to Settings > Bluetooth, or Settings > [your AirPods], and tap the More Info button next to your AirPods. If you don't see your AirPods in Settings > Bluetooth or in Settings > [your AirPods], just go to the next step.
5. Tap Forget This Device, and tap again to confirm.
6. With the lid open, press and hold the setup button on the back of the case for about 15 seconds, until the status light on the front of the case flashes amber, then white.*
7. Reconnect your AirPods: With your AirPods in their charging case and the lid open, place your AirPods close to your iPhone, iPad, or iPod touch. Follow the steps on your device's screen.
Best of luck.