1. The speaker hole may be blocked by a foreign object. Check it and clean it out if necessary. 2. Adjust the volume on your phone to check. 3. Press the function button on the Watch Pro and go to Settings>>Sounds>>Volume to modify the volume settings. 4. To experience the latest firmware features, you can upgrade the firmware to the latest version in the CMF Watch app. To do this, open the CMF Watch app, go to the Device page, and click Device Upgrade. 5. If the above steps do not resolve the issue, press the button on Watch Pro to enter Settings--System Menu. Click Reset. Then, check again to see if the issue is resolved.