sentences:  Consumer product companies now offer audio-delay adjustments to compensate for video-delay changes in TVs and A/V receivers, and several companies manufacture dedicated digital audio delays made exclusively for lip-sync error correction.For television applications, the Advanced Television Systems Committee recommends that audio should lead video by no more than 15 milliseconds and audio should lag video by no more than 45 milliseconds.However, the ITU performed strictly controlled tests with expert viewers and found that the threshold for detectability is -125ms to +45ms.