1. Check if the Mi Home APP has obtained permission to use the microphone (recording) of the mobile phone. If you have not obtained the permission, please turn on the relevant permissions in the settings of the mobile phone.
iOS device:
In the system settings, enable the microphone permission of the Mi Home APP;
Android device:
In the application permission management of the system settings, enable the microphone or recording permission of the Mi Home APP.
2. Check if the sound on the mobile phone is turned down too low resulting in no sound.