Why is there no sound on BBK's phone?

There is no sound when the mobile phone calls. I suggest you try to solve it in the following ways:

1, enter phone settings-sound-turn off mute, and turn up the ringtone volume.

2. Click a button on the up/down shortcut bar to clear and release the running memory.

3. Restart the phone.

4. Enter phone settings-General-Restore factory settings-Restore all settings/Clear all data (Restoring all settings will not delete files in the phone, please back up important data in the phone before clearing data).