On Thu, 20 Nov 2003 16:04:43 GMT, Carey Carlan
wrote:

Dithering smooths out the differences
between the 65,535 steps, making them as smooth as the 16 million steps.

Dither is just noise, but noise has a special property in this case.
Although it can't smooth out differences, it can remove errors. The
process of quantizing has fundamental errors estimating the smallest
bit, errors which track the signal itself. Dither randomizes this
error completely, leaving only noise.

A 24 bit conversion of the signal with the dither level of a 16 bit
conversion would have no more (or less) information than a 16 bit
conversion.

So, while the bits between the higher samples aren't necessary because
dithering smooths out the differences, the bottom 256 values between 16-bit
1 and 16-bit 0 allow you to use finer, quieter dithering that drops the
noise floor by 48 dB (ideally).

Perzactly!

Chris Hornbeck

"That is my theory, and what it is too."
Anne Elk