sentences:  The audio synchronizer receives the DDO signal and in response delays the audio by an equivalent amount, thereby maintaining proper audio-video sync.Modern audio synchronizers operate by digitizing and writing the audio signal into a ring memory, which is most commonly a RAM-based memory having independent read and write ability.At the appropriate delay time (as conveyed by the DDO) after an audio sample (or group of samples) are written into the memory, the previously stored audio sample is read from the ring memory.