Wednesday, February 23, 2011

Vol. I No. 23

"Digital audio is worse than you think it is."

Reader, my subject matter for this entry prompted me to record the above expression.

I once came across in my reading a mention that there at one point existed in ancient China a machine that could record and playback sound. It was said to have been a box which was used by government and military to relay messages. It was presumably a cylinder which took an impression from a cone-and-needle, similar to Edison's invention in the 1800's.

Consider for a moment the way this ancient invention and its Edisonian update function. Sound from the voice vibrates the cone, and the needle imprints the wax surface of the moving cylinder. During playback, the impressions in the wax cause the needle to vibrate more or less exactly as it did when the voice was vibrating it.

Consider how the cone and needle, held by a carriage upon the wax surface, can vibrate in any number of ways that will imprint the wax and later be reproduced. The sound of the speaker's voice, which in its richness, depth, and character of tone will move the air in all sorts of directions, in three dimensions, will move the cone, and hence the needle, similarly. And these movements in every direction will substantially be reflected by corresponding impressions in the wax - and thus will be reproduced in playback.

We all know how scientists, engineers, and technicians love their math. Both conceptually - for example on a blackboard or a graph - and also as actual output from test equipment such as oscilloscopes and oscillographs, they regard and deal with sound as a merely linear phenomenon. They neglect or forget all movement of the needle in that third dimension - up and down - which cannot be represented on a graph.

This is why I say that digital audio is worse than you think. It is a poor, intermittent estimate of the sound considered as merely two-dimensional, which entirely and completely neglects to represent any sound vibration in the third dimension.

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