The Influence of Video Quality on Perceived Audio Quality and Vice Versa

Three questions are being studied. Question one: To what extent is the perceived audio quality of an audiovisual stream influenced by the video quality? Question two is the reverse: To what extent is the perceived video quality of an audiovisual stream influenced by the audio quality? Finally: How do audio and video quality contribute to the overall perceived audiovisual quality? The quality ranges from broadcast audio and video quality to standard videophone (telephone) quality. The main conclusion is that when subjects are asked to judge the audio quality of an audiovisual stimulus, the video quality will contribute significantly to the subjectively perceived audio quality. The effect is about 1.2 points on a nine-point quality scale. The reversed effect is much smaller, about 0.2 point. Furthermore a simple mapping from the audio and video quality to the overall audiovisual quality is given, and it is shown that the video quality dominates the overall perceived audiovisual quality in nonconversational experiments.