There are some differences in our previous models and TVGuardian LT. TVGuardian LT mutes the audio on both a TV and surround sound receiver during the phrase containing the foul language. It will work with both HD and Standard (SD) TVs. However, the LT model does NOT display profanity-free closed captions.
We personally like the mute only experience with TVGuardian LT. If you have a previous model, you can get a feel for the experience by turning off the closed caption option.