Hi tr888,
Thanks for using Apple Support Communities! I see you're having an issue with your Bluetooth headset and I'd like to do what I can to help out.
Bluetooth devices can pick up interference, and this article has some tips to help with that: Resolve Wi-Fi and Bluetooth issues caused by wireless interference
Are your headphones connected to your iPhone?
If so, do you have the same issue when connected to a different device?
Do you have the same issue with another Bluetooth device connected to your iPhone?
If you put your iPhone into Airplane Mode, do you still have the same interference? If not, enable Wi-Fi while still in Airplane Mode and see if the interference starts up again. If not, turn off Airplane Mode, and see if it starts up again with the cellular connection active. This will help isolate to either connection.
Use Airplane Mode on your iPhone, iPad, iPod touch, and Apple Watch
Take care!