sentences:  These higher performance audio synchronizers allow the audio delay to track even large and quick video delay changes without generating any artifacts that are perceptible to even critical listeners for most audio program material.Recent development in video processing devices permit those devices to sense when a large video delay change will need to be made beforehand and allow that change information to be communicated to the audio synchronizer.The "advanced notice" from the video processing device allows the audio synchronizer to anticipate and take advantage of particular audio material (e.g., periods of relative silence or periods without music) to facilitate making corresponding large audio delay changes that do not risk generating noticeable audio artifacts.