There are several things that can be done to correct this however the television is dependent upon the source of the audio.
Low audio on all inputs and devices
If audio is low on one device while all others are ok, the device that encounters the issue will require troubleshooting and not the TV.
Some cable or satellite boxes will have their own audio controls for volume.
Check the audio settings of the TV
Try disabling/enabling “Auto Volume” or “Clear Voice”. Disabling these two features will remove some alteration of the audio by the TV. This will allow you to hear the program according to the broadcaster’s discretion.
You may want to adjust the sound mode based on the type of program you are viewing.
If the audio settings have been adjusted to an unwanted setting you can use the “SOUND RESET” to restore the TV to factory audio settings.
If the sound quality or volume is still not at the level you want, it is recommended to use a separate home theater system or amplifier to cope with different user environments.
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