Verify your TV is set to the appropriate input, make sure the volume is turned up.

Verify the audio cables are connected correctly and securely, verify any wireless/Bluetooth peripheral devices are connected.

Make sure the volume settings are adjusted to the appropriate level, and confirm that the loudspeaker is enabled.

Verify the audio codec on the Smart TV is compatible with the audio format of the media file.

Update the firmware, reset the TV, or restore the factory default settings.