!The Whisper Requires A Distortion
A digital channel with a limited number of bits is a rigid pipe. It has a fixed number of steps.
If you map those steps evenly across the entire range of human hearing, the loud sounds are captured perfectly, but the quiet whispers are crushed. A whisper might only span two or three digital steps, reducing a voice to a jagged, unintelligible buzz of quantization noise.
To save the whisper, the signal must be deliberately deformed before it enters the pipe.
An analog circuit compresses the signal logarithmically. It violently amplifies the quiet whispers, stretching them so they span dozens of digital steps, while aggressively squashing the loud shouts so they don’t clip the top of the scale.
The signal that travels through the digital pipe is warped and unnatural, a grotesque caricature where the quiet is as loud as the screaming.
But when it emerges on the other side, a mirror-image expander perfectly reverses the deformation, crushing the whispers back down to their true volume and pushing the shouts back to their peak.
The quantization noise, which attached itself to the amplified whisper in the pipe, is crushed down with it, vanishing below the threshold of hearing.
The whisper requires a distortion.
