Improper synchronization between audio and video results in audio track been late or early comparing to video picture, which especially noticeable while watching people talking (so called “LipSync” from lip synchronization). This issue is one of the most common and annoying in digital content playout and distribution and has cumulative effect with additive accumulation of the delays from every point of content transformation, processing and distribution.
Audio volume could vary between different station and different programs and regulators are trying to protect viewers demanding broadcasters, advertiser and content providers to normalize their loudness level to the recommended target. But advertising could still be much louder than program it breaks and from station to station we have to adjust volume of our receiver or TV set.
Audio signal absence or Silence (sometimes also called “No Audio” or “No Decodable Audio”) is a very annoying perceptual quality issue easily impacting your customer’s viewing experience.