you mean if you can turn the volume up and down of the speakers connected to your smart TV? If yes, then yes you can using the TV remote or you can connect your Android phone to your LG smart TV through WiFi but first check the procedures below:
How to Control a TV Using Wi-Fi
1. Connect the LG television to the “TV LAN” port on your router. Enable the LG television for Wi-Fi.
2. Navigate to the LG’s Home Dash Board screen. Open the “Setuo" menu followed by the “Network” menu.
3. Click “Configure settings” on the television screen.
4. Navigate to your Android device’s homescreen. Tap “Settings” followed by “Wireless and networks.” The LG television will recognize the Android device as a remote control.
5. Control the television’s control pointer with your Android device’s touch pad. Tap “Settings” to adjust touch pad sensitivity, designate a sound or vibration for each button tap and add a name for your television. Adjust the “Mute” setting to mute television volume during an incoming call and tap “My CH” to set channel preferences. Change volume or channel via the channel and volume wheel on your Android device’s display.