Engineering Brief
Experiments with Dither in Level-Calibrated Floating Point Audio Processing
AES Convention 135 · Paper 106 · October 2013
Abstract
The use of dither to decorrelate quantization error in fixed point signal processing systems is a well-established practice in professional audio. Floating point computation, however, is quite common due to the ease of use and ubiquity of high performance platforms, among other reasons. Dither is (anecdotally) less frequently found in floating point audio systems, until the final mapping to fixed point representation, but quantization error occurs in the rounding operation during intermediate calculations. Widrow and others have provided detailed treatment of the quantization error in floating point audio calculations, and in the present work experiments using dither during the internal rounding operation in a floating point unit are compared to the external addition of noise when the signal levels are known to be calibrated from the original analog source.
