Rec. ITU-R BT.1359-1 1 RECOMMENDATION ITU-R BT.1359-1 RELATIVE TIMING OF SOUND AND VISION FOR BROADCASTING

considering a) that a perceptible time difference between the sound and vision components of a television signal impairs the viewers’ reception of the programme; b) that separate picture and sound processing is becoming more and more widely used in broadcasting systems; c) that digital production and distribution equipment causes differential delay between the sound and vision signals; d) that programme production may involve tandem connected studios; e) that in studios the sound/vision relative timing should be the responsibility of the programme production directors; f) that the transmitting equipment and the receiver may introduce an additional, variable timing difference; g) that subjective evaluations show that detectability thresholds are about +45 ms to –125 ms and acceptability thresholds are about +90 ms to –185 ms on the average, a positive value indicates that sound is advanced with respect to vision,