extreme krypton 9 bluetooth key switch door music can be turned off. You can try to press the volume plus sign and minus sign on the battery cover for about 2 seconds at the same time. At this time, the blue light will flash 5 times, indicating that the operation is successful, and the prompts for events such as door lock opening and closing, Bluetooth connection and disconnection will be turned off. If you need to turn on the tone again, you can do it again in the same way.