Hello DAVE CHALLANT,
I understand your volume is low for your earbuds after updating to iOS 12.0.1. I am happy to help with this. If you haven't done so already, restart your iPhone.
Restart your iPhone, iPad, or iPod touch - Apple Support
Check all possibilities try different apps or even phone calls. Go to Settings > Sounds and adjust the volume there.
If you cant hear a person on a call or voicemail or if the sound isn't clear on your iPhone - Apple Support
Try the headphones with another device. If they are Bluetooth headphones unpair and then pair again to see if the issue persists.
Get help with your AirPods - Apple Support
- Go to Settings > Bluetooth and tap the icon next to your AirPods.1 Then tap Forget This Device.
- Put your AirPods in the case and close the lid. Wait 15 seconds, then open the lid.
- Press and hold the setup button on the back of the case until you see the status light flash amber a few times, then flash white.
- Place your AirPods close to your device. Follow the steps on your iOS device's screen.
Keep us posted.
Cheers!