Troubleshooting for malfunction of amplification is described as below :
1. Press the Volume Up button to increase volume when you talk on device.
2. Restart your device.
3. Update firmware to the latest version：Settings > About > System update > Check Update.
4. Access to Safe Mode ( long press power key > Tap and hold " Power Off " > Tap " ok "：If your phone / Tablet works well in Safe Mode ,malfunction may be caused by some 3rd party apps . Please reboot your device and check again if it works well.
5. Backup your data and perform factory reset.