This situation may be that the circuit board inside the phone has a leakage situation, so there will be a buzzing sound, it is recommended not to continue to charge the phone, you can take the phone to after-sales maintenance for overhaul.
I guess your phone must be a metal case of the usb will have a weak leakage, listening to the headset and the ear motor ring (moving iron) to form capacitance. You can try the headphone and touch the case with your hand