Videophone, teleconferencing, multimedia and other visual communication techniques often produce a delay in the video signal relative to voice signal, particularly at low bit rates. The delayed video sequence is visually annoying in real-time telecommunication services because the voice is not synchronized with the mouth movement or facial expression of the speaker. Inserting extra delay in the speech signal permits synchronization. However the delay occurs in both directions and produces undesirable discomfort.
USPTO Backgrounds
USPTO Backgrounds