As you already know, many people have trouble understanding the dialogue on TV. There can be many reasons for this. The most common reason is hearing loss. If a person is dealing with high frequency hearing loss, the sound can be muffled making it difficult to clearly understand what is being said.
Another reason that can cause trouble hearing the TV is the speaker placement. On your new flat screen TV, the speakers are smaller and are located near the back of the TV, thus creating a poorer sound quality than older TV's.
In some cases it is not even the TV at all, but rather the programming. Even some people with normal hearing might have trouble understanding what is being said, even if they have a speaker system or a sound bar. The dialogue gets drowned out by the music and/or the background noise made to "improve" the viewing experience.
Sometimes fixing the issue can be as simple as lowering the bass and increasing the treble on your TV settings due to the background noise tends to carry a larger bass emphasis while speech carries more treble.
While adding a speaker system or sound bar may help with the situation, we at KARE recommend the ChairSpeaker due to its Voice Enhancing Technology that emphasizes the human voice while deemphasizing the background sound. If you are having hearing issues when you are watching TV, then the ChairSpeaker will be the solution.