'Another problem associated with surround sound and the quadriga editing systems were the delays in picture information in relation to the soundtrack caused by the digital video effects device. Normally a slippage of one or two frames is tolerable with conventional television, but with HDTV this becomes a disturbing factor.

'The wide shot provides such a detailed image that synchronisation of percussion becomes essential.

'In fact, the mind perceives that it wishes to see a delay in sound - since it travels at 1100 feet per second, and we, the viewer, observe from a distant point.

'So does it then become necessary to advance the sound again to suit the close-ups?

'The present techniques of sound coverage tend to use spot effect microphones working close to the performers thereby producing adequate and synchronised sound for a close-up medium, but for the detailed wide screen perhaps we have to think again.