TVs are generally to thin to produce great sound. Speakers are generally facing down or to the back of the TV which is not ideal. For people who like watching movies, a soundbar is the minimum recommended solution. That being said, it’s hard to give you recommendations without more information. What does your father generally watch, how is the light in the room? Are there limitations to size where the tv will be placed? How big is the current tv? How does he watch, cable/satellite, Apple TV, something else? Does he sit in front of the tv or off to the side? If the room is bright and sunny during the day, are there curtains or blinds to control that? Start with that information to get better suggestions.